- Pd/C as a reusable catalyst for the coupling reaction of halophenols and arylboronic acids in aqueous media
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Pd/C was found to catalyze the Suzuki-Miyaura coupling reaction of halophenols in aqueous media. When halophenols were treated with ArB(OH)2 and a catalytic amount of 10% Pd/C (0.3 mol % Pd) in aqueous K2CO3 solution, the corresponding hydroxybiaryls were obtained in a high yield or quantitatively. The palladium catalyst was easily recovered and reused.
- Sakurai, Hidehiro,Tsukuda, Tatsuya,Hirao, Toshikazu
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- Efficient Syntheses of Star-Branched, Multifunctional Mesogens
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Star-branched molecular architectures lend themselves to convergent synthesis strategies for creating materials that combine three or more functional modalities, but these approaches require a core moiety with several reactive groups that are orthogonal t
- Song, Shuang,Rudick, Jonathan G.
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- Novel photochromism of differently-linked bis-benzopyrans
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The unique photochromic bis-chromene 5 incorporates the structural attributes of both 3 and 4. UV-vis irradiation of 5 leads to a dark brown colour, which is formed by mixing the purple and red colours observed for the photolysates of 3 and 4, respectively. The Royal Society of Chemistry.
- Moorthy, Jarugu Narasimha,Venkatakrishnan, Parthasarathy,Samanta, Subhas
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- Palladium supported on natural phosphate: Catalyst for Suzuki coupling reactions in water
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The Suzuki-Miyaura coupling reaction is one of the most important synthetic catalytic reactions developed in the 20th century. However, the use of toxic organic solvents for this reaction still poses a scientific challenge and is an aspect of economical and ecological relevance. The use of water as a reaction medium overcomes this issue. In the present work, we described efficient Suzuki coupling reactions in water, without any phase transfer reagents and it is possible to couple challenging substrates like aryl chlorides. Notably, this protocol also works with ultra-low loading of catalyst with high turnover numbers.
- Hassine, Ayoub,Sebti, Sa?d,Solhy, Abderrahim,Zahouily, Mohamed,Len, Christophe,Hedhili, Mohamed Nejib,Fihri, Aziz
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- Microwave assisted cross-coupling reactions using palladium nanoparticles in aqueous media
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Glucose stabilized palladium nanoparticles (PdNPs) have been prepared and the application of NPs in catalyzing both Suzuki and Heck reactions has been explored in aqueous media under microwave conditions. Both electron-rich and electron-deficient aryl halides can be coupled with a variety of boronic acids and styrene to access a wide variety of biaryl compounds and substituted alkenes in good to excellent yields. The catalyst can be recycled and reused four times with minimally affecting the morphology and efficiency of the nanoparticles. A plausible reaction mechanism has been proposed.
- Dhara, Kalyan,Parasar, Bibudha,Patil, Avinash J.,Dash, Jyotirmayee
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- Counteranion-Controlled Ag2O-Mediated Benzimidazolium Ring Opening and Its Application in the Synthesis of Palladium Pincer-Type Complexes
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We report a new approach to synthesize palladium complexes through Ag2O-promoted hydrolytic ring opening followed by palladium coordination. The novelty of Ag2O-promoted hydrolysis in comparison with the commonly used base-mediated hydrolysis lies in the anion-controlled product selectivity in the synthesis of pincer-type palladium complexes. Moreover, these palladium complexes have been tested in the Suzuki reaction using aryl bromides in methanol and H2O, respectively. In comparison with palladium complexes with normal coordination, the palladium complexes generated from the hydrolytic ring-opening coordination demonstrate excellent catalytic activity.
- Tao, Sheng,Guo, Cheng,Liu, Ning,Dai, Bin
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- A mixed cyclodextrin-biphenyl thermotropic liquid crystal: Synthesis, liquid-crystalline properties, and supramolecular organization
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A well-defined structure liquid crystal heptakis [6deoxy-6-(1-H-1,2,3- triazol-4-yl)(methyl)6-(4-methoxybiphenyl4'-yloxy) hexanoyl]-β-cyclodextrin (H6B-β-CD) was synthesized from propargyl 6-(4-methoxybiphenyl-4′- yloxy) hexanoate (P6B) and heptakis (6-deoxy-6-azido)-β-cyclodextrin ((N3)7-β-CD) by click reaction. The chemical structure of H6B-β-CD was confirmed by 1H NMR, FTIR, and MALDI-TOF MS. The thermal stability of the compound was investigated by thermogravimetric analysis (TGA). The liquid crystalline behavior was studied by differential scanning calorimetry (DSC), polarizing optical microcopy (POM), and wide-angle X-ray diffraction (WAXD) measurement. These investigations have shown that the supramolecular structure of H6B-β-CD are consisted of a large scale ordered lamellar structure and a small scale ordered structure (SmE) at low temperature region. As the temperature increases, the small scale structure becomes disordered relatively in the first instance, from smectic E to smectic A. Then, the lamellar structure collapses and nematic phase and isotropic phase are observed in sequence.
- Chen, Li,Hu, Tian-Hui,Xie, He-Lou,Zhang, Hai-Liang
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- Synthesis of Fluorenes and Dibenzo[ g,p]chrysenes through an Oxidative Cascade
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We have developed robust, operationally simple syntheses of fluorenes and of dibenzo[g,p]chrysenes through oxidative cascade processes. These structures that are commonly encountered in optoelectronic materials, dyes, and pharmaceutical products are acces
- Dickinson, Cody F.,Tius, Marcus A.,Yap, Glenn P. A.
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p. 1559 - 1563
(2022/02/07)
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- Discovery of Salidroside-Derivated Glycoside Analogues as Novel Angiogenesis Agents to Treat Diabetic Hind Limb Ischemia
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Therapeutic angiogenesis is a potential therapeutic strategy for hind limb ischemia (HLI); however, currently, there are no small-molecule drugs capable of inducing it at the clinical level. Activating the hypoxia-inducible factor-1 (HIF-1) pathway in skeletal muscle induces the secretion of angiogenic factors and thus is an attractive therapeutic angiogenesis strategy. Using salidroside, a natural glycosidic compound as a lead, we performed a structure-activity relationship (SAR) study for developing a more effective and druggable angiogenesis agent. We found a novel glycoside scaffold compound (C-30) with better efficacy than salidroside in enhancing the accumulation of the HIF-1α protein and stimulating the paracrine functions of skeletal muscle cells. This in turn significantly increased the angiogenic potential of vascular endothelial and smooth muscle cells and, subsequently, induced the formation of mature, functional blood vessels in diabetic and nondiabetic HLI mice. Together, this study offers a novel, promising small-molecule-based therapeutic strategy for treating HLI.
- Liu, Caiping,Han, Jingxuan,Marcelina, Olivia,Nugrahaningrum, Dyah Ari,Huang, Song,Zou, Meijuan,Wang, Guixue,Miyagishi, Makoto,He, Yun,Wu, Shourong,Kasim, Vivi
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supporting information
p. 135 - 162
(2022/01/14)
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- Selective C-O Bond Reduction and Borylation of Aryl Ethers Catalyzed by a Rhodium-Aluminum Heterobimetallic Complex
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We report the catalytic reduction of a C-O bond and the borylation by a rhodium complex bearing an X-Type PAlP pincer ligand. We have revealed the reaction mechanism based on the characterization of the reaction intermediate and deuterium-labeling experiments. Notably, this novel catalytic system shows steric-hindrance-dependent chemoselectivity that is distinct from conventional Ni-based catalysts and suggests a new strategy for selective C-O bond activation by heterobimetallic catalysis.
- Hara, Naofumi,Nakao, Yoshiaki,Saito, Teruhiko,Seki, Rin
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supporting information
p. 6388 - 6394
(2021/05/31)
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- Pd Nanoparticles Embedded Into MOF-808: Synthesis, Structural Characteristics, and Catalyst Properties for the Suzuki–Miyaura Coupling Reaction
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Abstract: A heterogeneous single-site catalyst Pd@MOF-808 was successfully synthesized by water-based, green synthesis procedure. The catalytic experiments exhibited the Pd@MOF-808 promoted efficiently the Suzuki–Miyaura coupling reaction without the assistance of organic phosphine ligands at atmospheric pressure conditions. The catalyst also could be applied in the gram-scale synthesis of industrially anti-inflanmatory analgestic Fenbufen. Graphic Abstract: [Figure not available: see fulltext.]
- Li, Tang,Pang, Wan,Wang, Jie,Zhang, Xiaoli,Zhao, Zesheng
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- Cost-effective bio-derived mesoporous carbon nanoparticles-supported palladium catalyst for nitroarene reduction and Suzuki–Miyaura coupling by microwave approach
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A new heterogeneous catalyst was synthesized by immobilizing Pd on areca nut kernel-derived carbon nanospheres (CNSs). The CNSs, without any further activation processes, accommodated 3% of Pd on their surface. The new Pd/CNS material was used for the reduction of nitroarenes and Suzuki–Miyaura coupling of bromoarenes with aryl boronic acids. The reactions were conducted under microwave irradiation at 160 °C using 12 mol% of Pd/CNS (0.36% actual Pd content). The reduction of nitroarenes into their respective amino compounds was achieved in 10–20 min (conversion up to 100%); by contrast, the Suzuki–Miyaura reactions yielded up to 98% at 150 °C with 10 mol% of Pd/CNS catalyst. The products were identified using gas chromatography and nuclear magnetic resonance spectroscopy. The catalyst was isolated from reaction mixture and reused without any significant loss in the activity. Thus, the present work introduces one-pot-derived porous CNSs as efficient catalytic support to Pd, establishing an alternative to existing Pd/C in terms of cost and efficiency.
- Supriya,Ananthnag, Guddekoppa S.,Shetti, Vijayendra S.,Nagaraja,Hegde, Gurumurthy
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- A one-pot protocol for the fluorosulfonation and Suzuki coupling of phenols and bromophenols, streamlined access to biaryls and terphenyls
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A one-pot protocol for the fluorosulfation and Suzuki coupling of phenols is described. The tandem reaction proceeds efficiently at room temperature, and various biaryls and biaryl fluorosulfates were obtained in good to excellent yields. Furthermore, biaryl fluorosulfates were utilized as versatile building blocks for the preparation of terphenyls. The Royal Society of Chemistry 2020.
- Hu, Rui,Li, Xinmin,Ren, Changyue,Yuan, Zeli,Zhang, Hang,Zhang, Tingting
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supporting information
p. 4748 - 4753
(2020/08/17)
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- Pd-catalyzed protecting-group-free cross-couplings of iodophenols with atom-economic triarylbismuth reagents
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An efficient protocol for the protecting-group-free synthesis of unsymmetrical hydroxybiaryls via the Pd-catalyzed cross-couplings of unprotected iodophenols with triarylbismuth reagents is described. The presented protocols exhibits good to high yields of hydroxybiaryls.
- Rao, Maddali L.N.,Meka, Suresh
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- Room-Temperature Aqueous Suzuki-Miyaura Cross-Coupling Reactions Catalyzed via a Recyclable Palladium@Halloysite Nanocomposite
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A reliable method for encapsulation of palladium nanoparticles (6-8 nm particles) in halloysite (Pd@Hal) has been developed. The Pd@Hal was found to be a highly efficient room-temperature catalyst for Suzuki-Miyaura cross-coupling reactions that gave high yields of a diverse array of coupling products in 5:2 n-PrOH/H2O within 1 h. The catalytic system was remarkably effective with a broad substrate scope. In addition, the catalyst was easily recovered and recycled without a significant loss of catalytic activity.
- Hamdi, Jumanah,Blanco, Alexis A.,Diehl, Brooke,Wiley, John B.,Trudell, Mark L.
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supporting information
p. 3471 - 3475
(2019/04/25)
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- Magnetically induced Suzuki and Sonogashira reaction performed using recyclable, palladium-functionalized magnetite nanoparticles
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A magnetically reusable, ligand-free palladium functionalized Fe3O4 catalyst system was successfully prepared. To overcome current problems such as the recyclability of the nanoparticle and the control and safety of the reaction, full advantage of the magnetite support was used. The palladium functionalized magnetite nanoparticle was removed by precipitation using a permanent magnet, while local heating, around the catalytic site, was induced using an external magnetic field. It was found that it was possible to perform the Suzuki reaction resulting in good to excellent conversions under air, with a magnetic field strength of 210 G and a frequency of 160 kHz. Despite the good results for the Suzuki reaction, it was not possible to perform the Sonogashira reaction magnetically due to an insufficient heat generation around the catalytic site. Further, the reusable catalyst system was recycled and reused for five times, resulting in a separable and straightforward catalyst system with the advantage of having full control of the reaction.
- De Cattelle, Amaury,Billen, Arne,Brullot, Ward,Verbiest, Thierry,Koeckelberghs, Guy
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supporting information
(2019/08/26)
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- Ligand-free, recyclable palladium-functionalized magnetite nanoparticles as a catalyst in the Suzuki-, Sonogashira, and Stille reaction
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A magnetically reusable ligand-free Fe3O4 palladium functionalized catalyst system was successfully prepared without the use of reducing agents, but by making use of the reduction potential of magnetite. The stabilizer was variated depending on the investigated reaction, whereby poly(ethylene glycol) (PEG) stabilized nanoparticles were used for the Suzuki reaction, as it requires protic conditions, while oleic acid stabilized nanoparticles were used for the Sonogashira and Stille reaction. It was found that it was possible to perform the Suzuki reaction and the Sonogashira reaction resulting in good to excellent conversions under air. Despite the good results for the Suzuki and the Sonogashira reaction it was not possible to perform the Stille reaction using this easily synthesized catalyst system due to the poisoning of the reusable catalyst by the tin-compound. Furthermore, the reusable catalyst system was recycled and reused for five times, resulting in a separable, straightforward and less time-consuming catalyst system.
- De Cattelle, Amaury,Billen, Arne,O'Rourke, Galahad,Brullot, Ward,Verbiest, Thierry,Koeckelberghs, Guy
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- Sustainable Ligand-Free, Palladium-Catalyzed Suzuki–Miyaura Reactions in Water: Insights into the Role of Base
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A simple and efficient system was developed for the ligand-free Pd-catalyzed Suzuki–Miyaura reaction in water under mild conditions. Quaternary ammonium hydroxides with long chains were found to be very suitable bases. This ligand-free Pd-catalyzed Suzuki–Miyaura reaction showed improved durability in water with Pd loadings decreased to ppm level. Bases were shown to stabilize active palladium species in addition to acting as a base during the catalytic process. In the catalytic system with a strong base, the soluble active PdII ion exhibited anti-reduction properties, which prevented aggregation and deactivation of Pd species. The entire catalytic system could be recycled after separating the product by simple filtration. The water-compatible and air-stable effective catalytic protocol described herein represents an attractive and green synthetic advance in Suzuki–Miyaura couplings.
- Wang, Yanyan,Liu, Yuanyuan,Zhang, Wei-qiang,Sun, Huaming,Zhang, Kan,Jian, Yajun,Gu, Quan,Zhang, Guofang,Li, Jiyang,Gao, Ziwei
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p. 5265 - 5273
(2019/11/29)
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- Iron-Catalyzed Room Temperature Cross-Couplings of Bromophenols with Aryl Grignard Reagents
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Herein we report a room temperature Fe-catalyzed coupling reaction of various bromophenols with aryl Grignard reagents, which exhibits a wide substrate scope and high functional group tolerance. For the first time, the combination of simple Fe(acac)3/PBu3/Ti(OEt)4 has been used as an effective catalyst for the biaryl couplings of bromophenols or their Na or K salts with debromination and etherification side reactions being well suppressed. Various biphenols including natural product garcibiphenyl C as well as pharmaceutical diflunisal and its ethyl ester were facilely synthesized using the present protocol. (Figure presented.).
- Xu, Li-Chen,Liu, Kun-Ming,Duan, Xin-Fang
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p. 5421 - 5427
(2019/11/14)
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- Experimental evidence for the formation of cationic intermediates during iodine(iii)-mediated oxidative dearomatization of phenols
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Iodine(iii)-based oxidants are commonly used reagents for the oxidative dearomatization of phenols. Having a better understanding of the mechanism through which these reactions proceed is important for designing new iodine(iii)-based reagents, catalysts, and reactions. We have performed a Hammett analysis of the oxidative dearomatization of substituted 4-phenylphenols. This study confirms that iodine(iii)-mediated oxidative dearomatizations likely proceed through cationic phenoxenium ions and not the direct addition of a nucleophile to an iodine-bound phenol intermediate.
- Tang, Ting,Harned, Andrew M.
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supporting information
p. 6871 - 6874
(2018/10/02)
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- High Throughput Experimentation and Continuous Flow Validation of Suzuki–Miyaura Cross-Coupling Reactions
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Traditional methods to discover optimal reaction conditions for small molecule synthesis is a time-consuming effort that requires large quantities of material and a significant expenditure of labor. High-throughput techniques are a potentially transformative approach for reaction condition screening, however, rapid validation of the reaction hotspots under continuous flow conditions remains necessary to build confidence in high throughput screening hits. Continuous flow technology offers the opportunity to upscale the screening hotspots and optimize their output of the target compounds due to the exceptional heat and mass transfer ability of flow reactions that are conducted in a smaller and safer reaction volume. We report a robotic high throughput technique to execute reactions in multi-well plates that were coupled with fast mass spectrometric analysis using an autosampler to accelerate the reaction screening process. Palladium-catalyzed Suzuki–Miyaura cross-coupling reactions were screened in this system and a heat map was generated to identify the best reaction conditions for downstream scale-up under continuous flow. Here, high throughput experimentation reactions in 96-well plates were performed for 1 h at 50 °C, 100 °C, 150 °C, and 200 °C before diluting them into 384-well plates for mass analysis. With the aid of high throughput tools, 648 unique experiments were conducted in duplicate. The cross-coupling reactions were evaluated as a function of stoichiometry, temperature, concentration, order of addition, and substrate type. The hotspots from high throughput experimentation were examined using a microfluidic Chemtrix system that confirmed the positive reaction leads as true positives. Negative outcomes identified by these experiments were found to be true negatives by microfluidic reaction evaluation. Quantitation of product yields was performed using high-performance liquid chromatography-mass spectrometry (HPLC/MS-MS).
- Jaman, Zinia,Mufti, Ahmed,Sah, Samyukta,Avramova, Larisa,Thompson, David H.
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supporting information
p. 9546 - 9554
(2018/07/14)
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- Method for preparing biaryl compound by using aryl sulfuryl fluoride as raw material
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The invention discloses a method for preparing a biaryl compound by using aryl sulfuryl fluoride as a raw material. The method comprises the following steps: adding a palladium catalyst, the aryl sulfuryl fluoride, an aryl boride and alkali into a round-bottom flask in sequence; magnetically stirring at a room temperature for carrying out Suzuki cross coupling reaction; after completing the reaction, adding a saturated saline solution for carrying out quenching reaction; extracting a reaction product from a reaction mixture by using ethyl acetate; merging organic phases; concentrating filtrate, and carrying out column chromatography isolation, thus obtaining the analytically pure biaryl compound, wherein the reaction is as shown in a following formula which is shown in the description. Byusing the method disclosed by the invention, on one hand, the production cost of the biaryl compound is reduced, and on the other hand, the method has a wide application prospect in aspects such as natural products, medicines, pesticides, herbicides and synthesis of high polymer conductive materials and liquid crystal materials.
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Paragraph 0058-0059
(2018/06/14)
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- Nickel-Catalyzed Amination of Silyloxyarenes through C–O Bond Activation
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Silyloxyarenes were utilized as electrophilic coupling partners with amines in the synthesis of aniline derivatives. A diverse range of amine substrates were used, including cyclic or acyclic secondary amines, secondary anilines, and sterically hindered primary anilines. Additionally, a range of sterically hindered and unhindered primary aliphatic amines were employed, which have previously been challenging with other classes of aryl ether electrophiles. Orthogonal couplings of silyloxyarenes with aryl methyl ethers are illustrated, where selectivity between the two C?O electrophiles is determined by ligand control, thereby allowing complementary and selective late-stage diversification of either electrophile. Finally, a sequential coupling displays the utility of this amination method along with the reversal in intrinsic reactivity between aryl methyl ethers and silyloxyarenes.
- Wiensch, Eric M.,Montgomery, John
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supporting information
p. 11045 - 11049
(2018/07/31)
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- AMINATION AND HYDROXYLATION OF ARYLMETAL COMPOUNDS
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In one aspect, the present disclosure provides methods of preparing a primary or secondary amine and hydroxylated aromatic compounds. In some embodiments, the aromatic compound may be unsubstituted, substituted, or contain one or more heteroatoms within the rings of the aromatic compound. The methods described herein may be carried out without the need for transition metal catalysts or harsh reaction conditions.
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Paragraph 0098; 0226; 0233
(2018/03/25)
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- Method for preparing biaryl compound under solvent-free condition
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The invention discloses a method for preparing a biaryl compound under a solvent-free condition. The method comprises the following steps: sequentially adding 0.0025-0.005mmol of palladium catalyst, 0.5mmol of aryl halide, 1.0mmol of arylboronic acid and 1.5-2.5mmol of alkali into a round-bottom flask; magnetically stirring at 25 DEG C to perform a Suzuki cross-coupling reaction for 12-24 hours; adding 15mL of saturated saline solution for quenching reaction after the reaction is completed; extracting a reaction product from the reaction mixture with 15mL of ethyl acetate; combining organic phases, concentrating filtrate, and separating with column chromatography to obtain an analytically pure biaryl compound. According to the method, solvent is not required to be added, the pollution problem of organic solvent on the environment can be solved, and the problems of product separation difficulty and difficult surfactant synthesis since water is used as solvent can be avoided. The method has wide application prospect in the fields of synthesis of natural products, medicines, pesticides, herbicide, high-molecular conductive materials and liquid crystal materials.
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Paragraph 0037
(2017/08/30)
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- An acetatopalladium(II) complex with 1-benzyl-N-(3,5-di-tert-butylsalicylidene)piperidin-4-amine: Synthesis, structure and catalytic applications in Suzuki–Miyaura coupling of arylboronic acids with hydroxyaryl halides
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The Schiff base 1-benzyl-N-(3,5-di-tert-butylsalicylidene)piperidin-4-amine (HL) and its acetatopalladium(II) complex having the formula [Pd(L)(OAc)] were synthesized. Both HL and [Pd(L)(OAc)] were characterized using elemental analysis and various spectroscopic (infrared, UV–visible, 1H NMR and 13C NMR) and mass spectrometric measurements. The molecular structure of the complex was determined using X-ray crystallographic analysis. In the complex, the pincer-like NNO-donor L? and the monodenate OAc? provide a distorted square-planar N2O2 coordination environment around the metal centre. The physicochemical properties and the spectroscopic features of [Pd(L)(OAc)] are consistent with its molecular structure. The complex was found to be an effective catalyst for the Suzuki–Miyaura cross-coupling reactions of hydroxyaryl halides with arylboronic acids in predominantly aqueous media. The reactions afforded hydroxybiaryl products in good to excellent yields with a wide substrate scope.
- Keesara, Srinivas,Narendra Babu,Pal, Samudranil
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- Strongly Chemiluminescent Acridinium Esters under Neutral Conditions: Synthesis, Properties, Determination, and Theoretical Study
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Various novel acridinium ester derivatives having phenyl and biphenyl moieties were synthesized, and their optimal chemiluminescence conditions were investigated. Several strongly chemiluminescent acridinium esters under neutral conditions were found, and then these derivatives were used to detect hydrogen peroxide and glucose. Acridinium esters having strong electron-withdrawing groups such as cyano, methoxycarbonyl, and nitro at the 4-position of the phenyl moiety in phenyl 10-methyl-10λ4-acridine-9-carboxylate trifluoromethanesulfonate salt showed strong chemiluminescence intensities. The chemiluminescence intensity of 3,4-dicyanophenyl 10-methyl-10λ4-acridine-9-carboxylate trifluoromethanesulfonate salt was approximately 100 times stronger than that of phenyl 10-methyl-10λ4-acridine-9-carboxylate trifluoromethanesulfonate salt at pH 7. The linear calibration ranges of hydrogen peroxide and glucose were 0.05-10 mM and 10-2000 μM using 3,4-(dimethoxycarbonyl)phenyl 10-methyl-10λ4-acridine-9-carboxylate trifluoromethanesulfonate salt at pH 7 and pH 7.5, respectively. The proposed chemiluminescence reaction mechanism of acridinium ester via a dioxetanone structure was evaluated via quantum chemical calculation on density functional theory. The proposed mechanism was composed of the nucleophilic addition reaction of hydroperoxide anion, dioxetanone ring formation, and nonadiabatic transition due to spin-orbit coupling around the transition state (TS) to the triplet state (T1) following the decomposition pathway. The TS which appeared in the thermal decomposition would be a rate-determining step for all three processes.
- Nakazono, Manabu,Oshikawa, Yuji,Nakamura, Mizuho,Kubota, Hidehiro,Nanbu, Shinkoh
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p. 2450 - 2461
(2017/03/11)
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- Rapid heteroatom transfer to arylmetals utilizing multifunctional reagent scaffolds
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Arylmetals are highly valuable carbon nucleophiles that are readily and inexpensively prepared from aryl halides or arenes and widely used on both laboratory and industrial scales to react directly with a wide range of electrophiles. Although C-C bond formation has been a staple of organic synthesis, the direct transfer of primary amino (-NH2) and hydroxyl (-OH) groups to arylmetals in a scalable and environmentally friendly fashion remains a formidable synthetic challenge because of the absence of suitable heteroatom-transfer reagents. Here, we demonstrate the use of bench-stable N-H and N-alkyl oxaziridines derived from readily available terpenoid scaffolds as efficient multifunctional reagents for the direct primary amination and hydroxylation of structurally diverse aryl- and heteroarylmetals. This practical and scalable method provides one-step synthetic access to primary anilines and phenols at low temperature and avoids the use of transition-metal catalysts, ligands and additives, nitrogen-protecting groups, excess reagents and harsh workup conditions.
- Gao, Hongyin,Zhou, Zhe,Kwon, Doo-Hyun,Coombs, James,Jones, Steven,Behnke, Nicole Erin,Ess, Daniel H.,Kürti, László
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p. 681 - 688
(2017/06/30)
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- 3-Hydroxypyrimidine-2,4-diones as Selective Active Site Inhibitors of HIV Reverse Transcriptase-Associated RNase H: Design, Synthesis, and Biochemical Evaluations
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Human immunodeficiency virus (HIV) reverse transcriptase (RT) associated ribonuclease H (RNase H) remains an unvalidated antiviral target. A major challenge of specifically targeting HIV RNase H arises from the general lack of selectivity over RT polymerase (pol) and integrase (IN) strand transfer (ST) inhibitions. We report herein the synthesis and biochemical evaluations of three novel 3-hydroxypyrimidine-2,4-dione (HPD) subtypes carefully designed to achieve selective RNase H inhibition. Biochemical studies showed the two subtypes with an N-1 methyl group (9 and 10) inhibited RNase H in low micromolar range without siginificantly inhibiting RT polymerase, whereas the N-1 unsubstituted subtype 11 inhibited RNase H in submicromolar range and RT polymerase in low micromolar range. Subtype 11 also exhibited substantially reduced inhibition in the HIV-1 INST assay and no significant cytotoxicity in the cell viability assay, suggesting that it may be amenable to further structure-activity relationship (SAR) for identifying RNase H inhibitors with antiviral activity.
- Tang, Jing,Liu, Feng,Nagy, Eva,Miller, Lena,Kirby, Karen A.,Wilson, Daniel J.,Wu, Bulan,Sarafianos, Stefan G.,Parniak, Michael A.,Wang, Zhengqiang
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p. 2648 - 2659
(2016/04/10)
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- A highly efficient and reusable palladium(II)/cationic 2,2′-bipyridyl-catalyzed stille coupling in water
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A water-soluble PdCl2 (NH3 )2 /cationic 2,2′ -bipyridyl system was found to be a highly efficient catalyst for Stille coupling of aryl iodides and bromides with organostannanes. The coupling reaction was conducted at 110°C in water, under aerobic conditions, in the presence of NaHCO3 as a base to afford corresponding Stille coupling products in good to high yields. When aryltributylstannanes were employed, the reactions proceeded smoothly under a very low catalyst loading (as little as 0.0001 mol %). After simple extraction, the residual aqueous phase could be reused in subsequent runs, making this Stille coupling economical. In the case of tetramethylstannane, however, a greater catalyst loading (1 mol %) and the use of tetraethylammonium iodide as a phase-transfer agent were required in order to obtain satisfactory yields.
- Wu, Wei-Yi,Liu, Ling-Jun,Chang, Fen-Ping,Cheng, Yu-Lun,Tsai, Fu-Yu
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- Palladium salt and functional reduced graphene oxide complex: in situ preparation of a generally applicable catalyst for C-C coupling reactions
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A novel Pd catalyst was designed by affording Pd2+ salt on the surface of functional reduced graphene oxide (FRGO), providing a new cheap and stable in situ prepared palladium catalyst for C-C coupling reactions, including the Heck reaction, Suzuki reaction, C-H bond functionalization reactions of thiophenes, and terminal alkyne C-H activation and homocoupling.
- Wang, Sheng,Hu, Donghua,Hua, Wenwen,Gu, Jiangjiang,Zhang, Qiuhong,Jia, Xudong,Xi, Kai
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p. 53935 - 53939
(2015/06/30)
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- PROTON-TRANSLOCATING COMPOUND, PROTON-TRANSLOCATING MATERIAL COMPOSITION, ELECTRONIC DEVICE AND PROTON-TRANSLOCATING ELECTROLYTE FILM
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PROBLEM TO BE SOLVED: To provide a proton-translocating compound and a proton-translocating material composition which are capable of maintaining a liquid crystal phase in a wide temperature range and thereby function in a wide temperature range, and various electronic devices using the compound or composition. SOLUTION: The proton-translocating compound is represented by the general formula (1) in the figure. COPYRIGHT: (C)2015,JPOandINPIT
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Paragraph 0117
(2016/10/10)
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- Novel glycosyl pyridyl-triazole@palladium nanoparticles: Efficient and recoverable catalysts for C-C cross-coupling reactions
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We report the development of a series of glycosyl pyridyl-triazole@palladium nanoparticles (GPT-Pd) which were synthesized by the reaction of azidoglycosides with 2-ethynylpyridine via click chemistry. These palladium nanoparticles were obtained in high yields and were fully characterized by 1H and 13C NMR, elemental analysis, transmission electron microscopy, and thermogravimetric analysis. The single crystal structure of GPT-Pd catalyst 5c was determined to show that the glycosyl pyridyl-triazole coordinated with palladium in a bidentate (N,N) coordination mode. Their use in palladium-catalyzed C-C coupling reactions such as Suzuki-Miyaura coupling, Heck reaction and Sonogashira reaction achieved quantitative production under mild conditions. Furthermore, the catalysts can be easily separated from the reaction mixture and the catalytic activity remained unchanged even after 8 successive catalytic cycles. This journal is
- Shen, Hongyun,Shen, Chao,Chen, Chao,Wang, Anming,Zhang, Pengfei
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p. 2065 - 2071
(2015/04/14)
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- Room temperature Suzuki coupling of aryl iodides, bromides, and chlorides using a heterogeneous carbon nanotube-palladium nanohybrid catalyst
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Palladium nanoparticles were immobilized on multi-walled carbon nanotubes by a layer-by-layer approach, resulting in a well-defined assembly. The nanohybrid was found effective in promoting Suzuki cross couplings of various halogenated aromatics, including chlorinated ones, with arylboronic acids under sustainable conditions. The heterogeneous catalyst could also easily be recovered from the reaction mixture and reused with no loss of activity over several cycles. This journal is
- Jawale, Dhanaji V.,Gravel, Edmond,Boudet, Caroline,Shah, Nimesh,Geertsen, Valérie,Li, Haiyan,Namboothiri, Irishi N. N.,Doris, Eric
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p. 2388 - 2392
(2015/04/14)
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- Preparation and characterization of side-chain liquid crystal polymer/paraffin composites as form-stable phase change materials
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A series of side-chain liquid crystal polymers (SCLCPs), named poly[ω-(4′-n-alkyloxybiphenyl-4-oxy) hexyl methacrylates] (P6biCm, m = 1, 2, 4, 6, 8, 10, 12, 14, 16 and 18), have been synthesized. Novel SCLCP/paraffin composite form-stable phase change materials (FSPCMs) were prepared by introducing P6biCm into paraffin. The minimum gelation concentration (MGC) and gel-to-sol transition temperature (TGS) properties were tested by a tube-testing method . It was found that P6biCm (m = 1, 2, 4, 6, 8, 10) were insoluble in paraffin, while P6biCm (m = 12, 14, 16, 18) exhibited a low MGC (≤6 wt%) and high TGS (TGS of P6biC12/paraffin is 140 °C). The structure and morphology of FSPCMs were systematically investigated by FT-IR, POM, 1D WXAD and SEM. The experimental results revealed that paraffin was restricted in the three-dimensional P6biCm network, leading to the FSPCM without leakage even above its melting point. The thermal properties were studied by DSC and TG. The research showed that the P6biCm/paraffin exhibited excellent thermal stability and high heat storage density. The shape stability was assessed by rheological measurements, indicating that solid hard gel soft gel liquid was observed with the increase of temperature. This work is useful in comprehending the physical mechanism of shape stability and in the meanwhile provides a novel method for synthesis of FSPCMs.
- Wu, Dang,Ni, Bin,Liu, Yujie,Chen, Sheng,Zhang, Hailiang
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p. 9645 - 9657
(2015/06/24)
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- Influence of main-chain and molecular weight on the phase behaviors of side-chain liquid crystalline polymers without the spacer
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A series of end-on side-chain liquid crystalline polymers (SCLCPs) based on a biphenyl mesogen, poly(4,4′-alkoxybiphenyl acrylate) (PBiA-m, m = 1, 4, 6, 10, 18), were successfully synthesized by free radical polymerization or reversible addition fragmentation chain transfer (RAFT) polymerization. The chemical structures of the monomers were confirmed by 1H NMR and mass spectrometry. The phase structures and transition behaviors were studied using DSC, POM and 1D WAXD. The experimental results found that PBiA-m showed the bilayer smectic phase and a higher clearing point (Ti) compared with poly(4,4′-alkoxybiphenyl methacrylate) (PBiMA-m). In addition, poly(4,4′-hexyloxybiphenyl methacrylate) (PBiMA-6) and poly(4,4′-hexyloxybiphenyl acrylate) (PBiA-6) with different molecular weights (Mn) and low molecular weight distributions have been successfully synthesized via the RAFT polymerization. The results indicated that all the polymers exhibited a bilayer smectic phase and Ti increased as the Mn of PBiMA-6 and PBiA-6 increased. Moreover, PBiA-6 had a higher Ti compared with PBiMA-6 with a similar Mn value. All the results suggested that the main-chain (acrylate and methacrylate) and Mn had a great influence on the properties of SCLCPs without the spacer.
- Bin, Ni,Yongbin, Luo,Yujie, Liu,Sheng, Chen,Hailiang, Zhang
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supporting information
p. 6568 - 6577
(2015/08/11)
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- Suzuki-Miyaura coupling of halophenols and phenol boronic acids: Systematic investigation of positional isomer effects and conclusions for the synthesis of phytoalexins from pyrinae
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The Suzuki-Miyaura couplings of o-, m-, and p-halophenols with o-, m-, and p-phenol boronic acids were investigated for all combinations under standardized conditions, using Pd/C as a heterogeneous catalyst and water as a solvent. In the case of iodophenols, conventional heating was used, while for bromophenols significantly better results could be obtained using microwave irradiation. This systematic study revealed that 2,4′-biphenol is particularly difficult to access, irrespective of the starting materials used, but that these difficulties can be overcome by using different additives. The conclusions drawn from this investigation allowed us to identify conditions for the protecting group-free or minimized total synthesis of biaryl-type phytoalexins. These compounds possess antibacterial activity and are produced by fruit trees as a response to microbial infection.
- Schmidt, Bernd,Riemer, Martin
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p. 4104 - 4118
(2014/05/20)
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- Palladium-loaded renewable polymer as a green heterogeneous catalyst for cross-coupling reactions under microwave irradiation
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A new palladium catalyst was prepared by immobilising ligand 2, 2'-dipyridylamine on the backbone of an acidic rosin polymer from gum rosin, on to which palladium(II) was bound via coordination. The catalyst at a low loading of 0.2 mol% was found to be highly effective for Suzuki-Miyaura coupling reactions of aryl halides and arylboronic acids under microwave irradiation in the presence of 1 equiv. of Na2CO3, affording excellent yields of the corresponding biaryls. Moreover, the catalyst exhibited very good recyclability over three cycles.
- Pan, Dan,Wu, Aiqun,Li, Pengfei,Xu, Haitang,Lei, Fuhou,Shen, Liqun
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p. 715 - 718
(2015/03/03)
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- Peptide nanofibers decorated with Pd nanoparticles to enhance the catalytic activity for C-C coupling reactions in aerobic conditions
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We report the synergistic effects of peptide nanofibers decorated with Pd nanoparticles to enhance the catalytic activity for C-C coupling reactions in mild and aerobic conditions.
- Maity, Indrajit,Rasale, Dnyaneshwar B.,Das, Apurba K.
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p. 2984 - 2988
(2014/01/06)
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- Suzuki cross-coupling reaction over Pd-Schiff-base anchored mesoporous silica catalyst
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A new hybrid catalyst has been prepared by tethering a palladium(II) Schiff-base complex via post-synthesis modification of mesoporous silica, MCM-41. The Schiff-base has been derived from o-vanillin and 3-[(2-aminoethylamino)propyl]trimethoxysilane (ATMS) which is chemically anchored on MCM-41 via silicon alkoxide route. The anchored Schiff-base imposed a stable planar coordination sphere on the central palladium ion. The catalyst has been characterized by elemental analysis, small angle X-ray diffraction, FT-IR, UV-vis, N2 sorption study, transmission electron microscopy (TEM) studies and scanning electron microscopy (SEM) studies. X-ray and TEM measurement showed the mesoporosity of the catalyst. The activity of the catalyst has been assessed in the Suzuki CC cross coupling reaction using various phenyboronic acid in heterogeneous condition. High selectivity for the biaryl products containing both electron-donating and electron-withdrawing substituents, high turnover, mild reaction conditions and possibility of easy recycle makes the catalyst highly desirable to address the industrial needs and environmental concerns.
- Das, Soma,Bhunia, Susmita,Maity, Tanmoy,Koner, Subratanath
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p. 188 - 197
(2014/08/18)
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- Suzuki-miyaura cross-coupling reaction catalyzed by 4,4'-tbu2-2,2'- dipyridyl-palladium(II) dichloride complex in aqueous solvent under aerobic condition
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4 4'-di-tBu-2 2'-dipyridylpalladium(II) dichloride complex [(tBubpy)PdCl2] showed high efficiency for the Suzuki coupling reaction of aryl iodide and bromide with phenylboronic acid in alcohol solvent under aerobic condition. All reactions gave the isolated coupling products in moderate to excellent yields.
- Mkhalid,Al-Shaikh
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p. 2077 - 2082
(2014/06/09)
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- A biomimetic catalytic aerobic functionalization of phenols
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The importance of aromatic C-O, C-N, and C-S bonds necessitates increasingly efficient strategies for their formation. Herein, we report a biomimetic approach that converts phenolic C-H bonds into C-O, C-N, and C-S bonds at the sole expense of reducing dioxygen (O2) to water (H 2O). Our method hinges on a regio- and chemoselective copper-catalyzed aerobic oxygenation to provide ortho-quinones. ortho-Quinones are versatile intermediates, whose direct catalytic aerobic synthesis from phenols enables a mild and efficient means of synthesizing polyfunctional aromatic rings. The direct approach: Polyfunctional aromatic rings have been generated by direct functionalization of C-H bonds to C-O, C-N, and C-S bonds at the sole expense of reducing O2 to H2O. The method hinges on a regio- and chemoselective, copper-catalyzed aerobic oxygenation of phenols to provide ortho-quinones (see scheme), thus mimicking the ubiquitous biosynthetic pathway of melanogenesis.
- Esguerra, Kenneth Virgel N.,Fall, Yacoub,Lumb, Jean-Philip
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supporting information
p. 5877 - 5881
(2014/06/10)
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- An efficient microwave-assisted suzuki reaction using a new pyridine-pyrazole/Pd(II) species as catalyst in aqueous media
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A new pyridine-pyrazole N-N ligand has been conveniently synthesized and characterized by 1H-, 13C-NMR, IR spectroscopies, HRMS and X-ray single-crystal crystallography analyses. The ligand adds to palladium(II) under basic conditions to give high yields of an air-stable and water-soluble complex that was fully characterized by NMR and HRMS. The complex was investigated as a catalyst for the Suzuki reaction in aqueous media under microwave irradiation. The compound proved to be an effective catalyst.
- Shen, Liqun,Huang, Suyu,Nie, Yuanmei,Lei, Fuhou
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p. 1602 - 1612
(2013/04/10)
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- Nanoparticulate palladium catalyst stabilized by supported on feather keratin for Suzuki coupling reaction
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Palladium nanoparticles supported in a feather keratin matrix were efficient catalyst for the coupling reactions of aryl bromides with arylboronic acid in aqueous medium under mild reaction conditions. The biopolymer-based catalyst demonstrated excellent activity for substrates with a wide range of functional groups. The product biaryls were precipitated from the reaction mixture with good to excellent yields and purities. The catalyst was recovered from the reaction solution easily by simple filtration, and can be reused at least seven times.
- Ma, Hengchang,Bao, Zhikang,Han, Guobin,Yang, Ningning,Xu, Yufei,Yang, Zengming,Cao, Wei,Ma, Yuan
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p. 578 - 584
(2013/08/25)
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- Pd nanoparticle-silica nanotubes (Pd@SNTs) as an efficient catalyst for Suzuki-Miyaura coupling and sp2 C-H arylation in water
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Silica nanotubes (SNTs) functionalized with Pd-NPs on the inner surface performed as efficient nano-reactors for C-C coupling in water; the nano-confinement offers minimized leaching of Pd and yet efficient mass transfer for Suzuki-Miyaura coupling and C-H arylation of thiazoles in water with very high TON.
- Park, Ginam,Lee, Sanghee,Son, Sang Jun,Shin, Seunghoon
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supporting information
p. 3468 - 3473
(2013/12/04)
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- Virtual screening and optimization yield low-nanomolar inhibitors of the tautomerase activity of Plasmodium falciparum macrophage migration inhibitory factor
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The Plasmodium falciparum orthologue of the human cytokine, macrophage migratory inhibitory factor (PfMIF), is produced by the parasite during malaria infection and modulates the host's immune response. As for other MIF orthologues, PfMIF has tautomerase activity, whose inhibition may influence the cytokine activity. To identify small-molecule inhibitors of the tautomerase activity of PfMIF, virtual screening has been performed by docking 2.1 million compounds into the enzymatic site. Assaying of 17 compounds identified four as active. Substructure search for the most potent of these compounds, a 4-phenoxypyridine analogue, identified four additional compounds that were purchased and also shown to be active. Thirty-one additional analogues were then designed, synthesized, and assayed. Three were found to be potent PfMIF tautomerase inhibitors with Ki of ～40 nM; they are also highly selective with Ki > 100 μM for human MIF.
- Dahlgren, Markus K.,Garcia, Alvaro Baeza,Hare, Alissa A.,Tirado-Rives, Julian,Leng, Lin,Bucala, Richard,Jorgensen, William L.
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p. 10148 - 10159
(2013/01/16)
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- A mild robust generic protocol for the Suzuki reaction using an air stable catalyst
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A mild but robust procedure has been developed as a first pass generic protocol for the Suzuki-Miyaura reaction. The protocol employs an air stable palladium pre-catalyst at low loading (1 mol %) in aqueous solvent mixtures at moderate temperature using potassium carbonate as base. Under these mild conditions, most aryl bromides will react with sterically and electronically demanding aryl boronic acids to give complete conversion to the product biphenyls in less than 1 h. Aryl chlorides are also fully converted in most cases either under identical conditions in 8-24 h, or in 2 h at elevated temperature. A further advantage of these mild conditions of moderate temperature, weak base and benign solvent is that sensitive functional groups and structural motifs are well tolerated. In addition, the lipophilic biphenyl products are readily isolated after a simple work-up procedure. These generic conditions are ideal for proof of transformation, and as the starting point for development and optimization of a specific process. The discovery and fine-tuning of this generic protocol will be presented, supported extensively by examples to illustrate its scope and utility.
- Moseley, Jonathan D.,Murray, Paul M.,Turp, Edward R.,Tyler, Simon N.G.,Burn, Ross T.
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experimental part
p. 6010 - 6017
(2012/09/21)
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- Self-assembled poly(imidazole-palladium): Highly active, reusable catalyst at parts per million to parts per billion levels
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Metalloenzymes are essential proteins with vital activity that promote high-efficiency enzymatic reactions. To ensure catalytic activity, stability, and reusability for safe, nontoxic, sustainable chemistry, and green organic synthesis, it is important to develop metalloenzyme-inspired polymer-supported metal catalysts. Here, we present a highly active, reusable, self-assembled catalyst of poly(imidazole-acrylamide) and palladium species inspired by metalloenzymes and apply our convolution methodology to the preparation of polymeric metal catalysts. Thus, a metalloenzyme-inspired polymeric imidazole Pd catalyst (MEPI-Pd) was readily prepared by the coordinative convolution of (NH4)2PdCl4 and poly[(N-vinylimidazole)-co-(N- isopropylacrylamide)5] in a methanol-water solution at 80 °C for 30 min. SEM observation revealed that MEPI-Pd has a globular-aggregated, self-assembled structure. TEM observation and XPS and EDX analyses indicated that PdCl2 and Pd(0) nanoparticles were uniformly dispersed in MEPI-Pd. MEPI-Pd was utilized for the allylic arylation/alkenylation/vinylation of allylic esters and carbonates with aryl/alkenylboronic acids, vinylboronic acid esters, and tetraaryl borates. Even 0.8-40 mol ppm Pd of MEPI-Pd efficiently promoted allylic arylation/alkenylation/vinylation in alcohol and/or water with a catalytic turnover number (TON) of 20 000-1 250 000. Furthermore, MEPI-Pd efficiently promoted the Suzuki-Miyaura reaction of a variety of inactivated aryl chlorides as well as aryl bromides and iodides in water with a TON of up to 3 570 000. MEPI-Pd was reused for the allylic arylation and Suzuki-Miyaura reaction of an aryl chloride without loss of catalytic activity.
- Yamada, Yoichi M. A.,Sarkar, Shaheen M.,Uozumi, Yasuhiro
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supporting information; experimental part
p. 3190 - 3198
(2012/04/10)
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- A highly active catalytic system for Suzuki-Miyaura cross-coupling reactions of aryl and heteroaryl chlorides in water
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An easily available Pd(OAc)2/(2-mesitylindenyl) dicyclohexylphosphine/Me(octyl)3N+Cl-/K 3PO4·3H2O catalytic system was developed and it shows high catalytic activity in the Suzuki-Miyaura cross-coupling reaction of a diverse array of aryl and heteroaryl chlorides in water. Notably, this catalytic system also works with ultra-low loading of the catalyst with high turnover numbers.
- Mao, Shu-Lan,Sun, Yue,Yu, Guang-Ao,Zhao, Cui,Han, Zhi-Jun,Yuan, Jia,Zhu, Xiaolei,Yang, Qihua,Liu, Sheng-Hua
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p. 9410 - 9417
(2013/01/15)
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- Design, synthesis, and anti-proliferative evaluation of [1,1′-biphenyl]-4-ols as inhibitor of HUVEC migration and tube formation
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Allylated biphenol neolignans contain a variety of chemopreventive entities that have been used as anti-tumor drug leads. Herein, 37 allylated biphenols were evaluated for anti-proliferative activity by the MTT assay and inhibitory effect on the migration and tube formation of HUVECs featuring anti-angiogenic properties. 3-(2-Methylbut-3-en-2-yl)-3′,5′-bis(trifluoromethyl)-[1, 1′-biphenyl]-4-ol (5c) exerted an inhibitory effect on HUVECs compared to honokiol (IC50 = 47.0 vs. 52.6 μM) and showed significant blocking effects on the proliferation of C26, Hela, K562, A549, and HepG2 (IC 50 = 15.0, 25.0, 21.2, 29.5, and 13.0 μM, respectively), superior to those of honokiol (IC50 = 65.1, 62.0, 42.0, 75.0, and 55.4 μM, respectively). Importantly, compound 5c inhibited the migration and capillary-like tube formation of HUVECs in vitro.
- Ran, Yan,Ma, Liang,Wang, Xuewei,Chen, Jinying,Wang, Guangcheng,Peng, Aihua,Chen, Lijuan
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experimental part
p. 8091 - 8104
(2012/10/07)
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- An efficient protocol for the palladium-catalysed Suzuki-Miyaura cross-coupling
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The palladacyclic catalyst precursor received by ortho-palladation of ([1,1′-biphenyl]-2-yloxy)diisopropyl-phosphine represents a highly active system for Suzuki-Miyaura cross-coupling reactions when used in neat water. An efficient, broadly applicable and sustainable aqueous protocol was developed using 2.5 eq. of Na2CO3 as base, allowing the reaction to be performed under air and at ambient temperature with Pd loadings of 0.04 mol%. Coupling products are obtained in high yields and excellent purity by simple filtration with no organic solvents needed throughout the whole reaction. A broad variety of functional groups are tolerated and a large number of substrates can be applied with this protocol. The crystal structure of the palladacyclic catalyst precursor is presented as well as investigations targeting the nature of catalyst activation and the active catalytic species.
- Marziale, Alexander N.,Jantke, Dominik,Faul, Stefan H.,Reiner, Thomas,Herdtweck, Eberhardt,Eppinger, Joerg
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supporting information; experimental part
p. 169 - 177
(2011/03/23)
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- Palladium on carbon-catalyzed solvent-free and solid-phase hydrogenation and Suzuki-Miyaura reaction
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The solvent-free and solid-phase hydrogenation of various reducible functionalities was efficiently catalyzed by heterogeneous palladium on carbon (Pd/C) under ambient hydrogen pressure and temperature. The Pd/C-catalyzed Suzuki-Miyaura coupling reaction between solid aryl bromides and solid arylboronic acids to generate the corresponding solid biaryls was also achieved under the totally solid-phase conditions.
- Monguchi, Yasunari,Fujita, Yuki,Hashimoto, Shota,Ina, Mariko,Takahashi, Tohru,Ito, Ryo,Nozaki, Kei,Maegawa, Tomohiro,Sajiki, Hironao
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experimental part
p. 8628 - 8634
(2011/11/30)
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- Benzotriazole: An efficient, inexpensive and phosphine-free ligand for the palladium-catalyzed Suzuki-Miyaura reaction
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Benzotriazole has been disclosed as an efficient and inexpensive ligand for the palladium-catalyzed Suzuki-Miyaura cross-coupling reaction of arylhalides with arylboronic acids. This preparative convenient system afforded the corresponding coupling products, biaryls and terphenyls in good to excellent yields.
- Jha, Rajeev Ranjan,Chaudhary, Ritu,Chandra, Ramesh,Verma, Akhilesh Kumar
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experimental part
p. 1187 - 1194
(2012/04/04)
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