- Biaryl Cross-Coupling Enabled by Photo-Induced Electron Transfer
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We report a protocol for aryl cross-coupling of electron-deficient aryl halides with electron-rich (hetero)arenes that is driven solely by violet light. This process takes advantage of formation of photo-excited state of electron-deficient aryl halides, that are reduced by electron-rich (hetero)arenes to form a pair of aryl anion and cation radicals. The resulting aryl anion radicals of aryl halides undergo mesolysis of the carbon-halogen bond to generate aryl radicals, that are coupled most likely with aryl cation radicals to afford functionalized biaryls. (Figure presented.).
- Hayashi, Hirohito,Wang, Bin,Wu, Xiangyang,Teo, Shi Jie,Kaga, Atsushi,Watanabe, Kohei,Takita, Ryo,Yeow, Edwin K. L.,Chiba, Shunsuke
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supporting information
p. 2223 - 2231
(2020/04/30)
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- Pyridine substituted dibenzyl pyrimidine compound, and organic electroluminescence element thereof
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The invention provides a pyridine substituted dibenzyl pyrimidine compound with a structure represented by formula I, and an organic electroluminescence element adopted with the pyridine substituted dibenzyl pyrimidine compound, wherein X1, A1, and n are
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Paragraph 0086-0088; 0096-0098
(2019/08/12)
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- PYRIDINE-SUBSTITUTED DIPHENYLPYRIMIDINES COMPOUNDS AND ORGANIC ELECTROLUMINESCENT DEVICES USING THE SAME
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一種具式(I)結構之經吡啶取代之二苯基嘧啶化合物及使用該化合物之有機電激發光元件,其中,X1、A1及n係如同說明書中之定義。 The present invention provides pyridine-substituted diphenylpyrimidines compounds of formula (I) and an organic electroluminescent device using the same:wherein X1, A1and n are as defined in t
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Page/Page column 17-18; 21
(2019/11/26)
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- Base-Controlled Heck, Suzuki, and Sonogashira Reactions Catalyzed by Ligand-Free Platinum or Palladium Single Atom and Sub-Nanometer Clusters
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The assumption that oxidative addition is the key step during the cross-coupling reaction of aryl halides has led to the development of a plethora of increasingly complex metal catalysts, thereby obviating in many cases the exact influence of the base, which is a simple, inexpensive, and necessary reagent for this paramount transformation. Here, a combined experimental and computational study shows that the oxidative addition is not the single kinetically relevant step in different cross-coupling reactions catalyzed by sub-nanometer Pt or Pd species, since the reactivity control is shifted toward subtle changes in the base. The exposed metal atoms in the cluster cooperate to enable an extremely easy oxidative addition of the aryl halide, even chlorides, and allow the base to bifurcate the coupling. With sub-nanometer Pd species, amines drive to the Heck reaction, carbonate drives to the Sonogahira reaction, and phosphate drives to the Suzuki reaction, while for Pt clusters and single atoms, good conversion is only achieved using acetate as a base. This base-controlled orthogonal reactivity with ligand-free catalysts opens new avenues in the design of cross-coupling reactions in organic synthesis.
- Fernández, Estefanía,Rivero-Crespo, Miguel A.,Domínguez, Irene,Rubio-Marqués, Paula,Oliver-Meseguer, Judit,Liu, Lichen,Cabrero-Antonino, María,Gavara, Rafael,Hernández-Garrido, Juan C.,Boronat, Mercedes,Leyva-Pérez, Antonio,Corma, Avelino
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supporting information
p. 1928 - 1940
(2019/02/14)
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- Novel Insights into the Combination of Metal- and Biocatalysis: Cascade One-Pot Synthesis of Enantiomerically Pure Biaryl Alcohols in Deep Eutectic Solvents
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One of the pioneering examples of chemoenzymatic cascades in water such as the palladium-catalysed Suzuki-cross coupling followed by an enzymatic reduction has been revisited by the employment of a medium containing Deep Eutectic Solvents (DESs) for the catalytic performance. Thus, the unique properties of these neoteric solvents enabled to reach high substrate concentration for the overall process. Moreover, both isolated enzymes and whole cells exhibited excellent activities which allowed to obtain a set of chiral biaryl alcohols in good yields and very high enantiomeric excess (>99 %).
- Paris, Juraj,Ríos-Lombardía, Nicolás,Morís, Francisco,Gr?ger, Harald,González-Sabín, Javier
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p. 4417 - 4423
(2018/09/14)
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- Co/NHPI-mediated aerobic oxygenation of benzylic C-H bonds in pharmaceutically relevant molecules
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A simple cobalt(ii)/N-hydroxyphthalimide catalyst system has been identified for selective conversion of benzylic methylene groups in pharmaceutically relevant (hetero)arenes to the corresponding (hetero)aryl ketones. The radical reaction pathway tolerates electronically diverse benzylic C-H bonds, contrasting recent oxygenation reactions that are initiated by deprotonation of a benzylic C-H bond. The reactions proceed under practical reaction conditions (1 M substrate in BuOAc or EtOAc solvent, 12 h, 90-100 °C), and they tolerate common heterocycles, such as pyridines and imidazoles. A cobalt-free, electrochemical, NHPI-catalyzed oxygenation method overcomes challenges encountered with chelating substrates that inhibit the chemical reaction. The utility of the aerobic oxidation method is showcased in the multigram synthesis of a key intermediate towards a drug candidate (AMG 579) under process-relevant reaction conditions.
- Hruszkewycz, Damian P.,Miles, Kelsey C.,Thiel,Stahl, Shannon S.
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p. 1282 - 1287
(2017/02/10)
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- Pyridine sulfinates as general nucleophilic coupling partners in palladium-catalyzed cross-coupling reactions with aryl halides
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Pyridine rings are ubiquitous in drug molecules; however, the pre-eminent reaction used to form carbon-carbon bonds in the pharmaceutical industry, the Suzuki-Miyaura cross-coupling reaction, often fails when applied to these structures. This phenomenon is most pronounced in 2-substituted pyridines, and results from the difficulty in preparing, the poor stability of, and low efficiency in reactions of pyridine-2-boronates. We demonstrate that by replacing these boronates with pyridine-2-sulfinates, a cross-coupling process of unrivalled scope and utility is realized. The corresponding 3-And 4-substituted pyridine variants are also efficient coupling partners. In addition, we apply these sulfinates in a library format to the preparation of medicinally relevant derivatives of the drugs varenicline (Chantix) and mepyramine (Anthisan).
- Markovic, Tim,Rocke, Benjamin N.,Blakemore, David C.,Mascitti, Vincent,Willis, Michael C.
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p. 4437 - 4442
(2017/07/11)
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- Nickel-catalyzed one-pot Suzuki-Miyaura cross-coupling of phenols and arylboronic acids mediated by N,N-ditosylaniline
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An efficient method for the construction of two distinct C aryl-Caryl bonds through the Ni-catalyzed Suzuki-Miyaura cross-coupling of phenols with arylboronic acids has been developed. This reaction proceeds through the in situ tosylation of phenols by using N,N-ditosylaniline as the sulfonylating reagent, which is highly active, markedly stable, and easily prepared. The scope with respect to the coupling partners - phenols and boronic acids - is broad, and sensitive functional groups are tolerated. Phenols, especially those containing an unprotected amino group, which are generally problematic for coupling under conventional one-pot conditions, are also viable substrates in this transformation.
- Chen, Liangshun,Lang, Hongyue,Fang, Lei,Zhu, Mengyun,Liu, Jinqian,Yu, Jianjun,Wang, Limin
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supporting information
p. 4953 - 4957
(2014/08/18)
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- METHOD OF SYNTHESIS MOLECULES USING CATALYST AND COMPOSITES THEREOF
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A method to synthesis molecules is provided. The method employs a catalyst for a cross- coupling react ion to obtain the molecule. The method comprises coupling boronic acid and halide in presence of the catalyst having graphite oxide supported palladium nanoparticles, a solvent and a base by heating. The heating is performed at a temperature lower than the temperature at which the graphite oxide deforms. The molecule is a biaryl. The method further provides obtaining complexs such as boscalid, telmisartan, valsartan, and SPPARMγ.
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- Palladium nanoparticles on graphite oxide: A recyclable catalyst for the synthesis of biaryl cores
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The synthesis of life saving drug molecules in a cost-effective and environmentally benign pathway is of paramount significance. We present an environment friendly protocol to prepare core moieties of top selling drug molecules such as boscalid and telmisartan using Suzuki-Miyaura coupling conditions. In contrast to the traditional synthesis of these pharmaceutically important molecules, we have accomplished a graphite oxide (GO) supported palladium nanoparticles (PdNPs) based catalyst which quantitatively produced these core biaryl moieties of top selling drug molecules in a recyclable way. The catalytic activity remained unchanged even after 16 successive catalytic cycles without incorporating any palladium metal impurity in the pharmaceutically significant organic products. A detailed study including IR spectroscopy, solid state NMR spectroscopy, X-ray photoelectron spectroscopy, and DFT calculation was employed to understand the role of solid support on the nondecaying recycling ability of the catalyst during the Suzuki-Miyaura coupling reaction. The study indicates a strong chemical interaction of the different functionalities present in the GO, with the palladium centers which is primarily responsible for such sustained catalytic activity during the consecutive Suzuki-Miyaura coupling cycles.
- Santra, Subhankar,Hota, Pradip Kumar,Bhattacharyya, Rangeet,Bera, Parthasarathi,Ghosh, Prasenjit,Mandal, Swadhin K.
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p. 2776 - 2789
(2014/01/06)
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- Facile synthesis of 3-arylpyridine derivatives by palladacycle-catalyzed Stille cross-coupling reaction
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The Stille cross-coupling reaction of a variety of aryl halides (X=Cl, Br, I) with 3-alkylstannylpyridines highly catalyzed by cyclopalladated ferrocenylimine has been developed. This reaction allows formation of arylpyridine derivatives in moderate to excellent yields. Functional groups on aryl halides, such as amino, hydroxyl, keto, and aldehyde are tolerated and the reactions with arylbenzoxale substrates also proceed well.
- Ma, Gaizhi,Leng, Yuting,Wu, Yusheng,Wu, Yangjie
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p. 902 - 909
(2013/07/25)
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- Room-temperature Suzuki-Miyaura coupling of heteroaryl chlorides and tosylates
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Suzuki-Miyaura coupling of heteroaryls is an important method for the preparation of compound libraries for medicinal chemistry and materials research. Although many catalysts have been developed, none of them have been generally applicable to the coupling reactions of heteroaryl chlorides and tosylates at room temperature. We discovered that a catalyst combination of Pd(OAc)2 and XPhos (2-dicyclohexylphosphanyl-2',4',6'- triisopropylbiphenyl) could efficiently catalyze these couplings. Besides the choice of catalyst, the use of hydroxide bases in an aqueous alcoholic solvent was essential for fast couplings. These conditions promoted fast release of active catalyst (XPhos)Pd0, and accelerated the transmetalation in the catalytic cycle. Most of the major families of heteroaryl chlorides (31 examples) and tosylates (17 examples) reached full conversion within minutes to hours at room temperature. The method could be easily scaled up for gram-scale synthesis. Furthermore, we examined the relative reactivity of coupling partners in whole reactions. Electron-rich heteroaryl chlorides and tosylates reacted more slowly than electron-deficient ones, in the order of indole, pyrrole furan, thiophene > pyridine. Similarly, electron-deficient arylboronic acids were less reactive than electron-neutral and electron-rich ones. The reactivity trends from this study can help to choose appropriate coupling partners for Suzuki reactions.
- Yang, Junfeng,Liu, Sijia,Zheng, Jian-Feng,Zhou, Jianrong
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supporting information
p. 6248 - 6259,12
(2020/09/16)
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- Nickel-catalyzed cross-coupling of phenols and arylboronic acids through an in situ phenol activation mediated by PyBroP
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A new method for the Suzuki-Miyaura cross-coupling of phenols and arylboronic acids through in situ phenol activation mediated by PyBroP is presented. The reaction proceeds efficiently by using cost-effective, markedly stable [NiCl2(dppp)] (dppp=1,3-bis(diphenylphosphino)propane) as the catalyst in only 5 mol % loading, as well as in the absence of extra ligands. The method exhibits broad applicability and high efficiency towards a wide range of both phenols and boronic acids, including activated, nonactivated, deactivated, and heteroaromatic coupling partners. In addition, various functional groups, such as ether, amino, cyano, ester, and ketone groups, are compatible with this transformation. Notably, arylboronic acids containing an unprotected NH2 group and 2-heterocyclic boronic acids, which are generally problematic for coupling under conventional conditions, are also viable substrates, although moderate yields were obtained for sterically hindered substrates. Consequently, the in situ cross-coupling methodology coupled with the use of an inexpensive and stable nickel catalyst provides a rapid and efficient pathway for the assembly of biaryls and heterobiaryls with structural diversity from readily available phenol compounds.
- Chen, Guo-Jun,Huang, Jie,Gao, Lian-Xun,Han, Fu-She
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supporting information; experimental part
p. 4038 - 4042
(2011/05/05)
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- Cobalt-catalyzed preparation of arylindium reagents from aryl and heteroaryl bromides
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A cobalt-bathophenanthroline catalyst has been developed for the direct preparation of a variety of arylindium reagents from the corresponding aryl and heteroaryl bromides in the presence of indium metal and lithium chloride. The thus-formed arylindium reagents undergo efficient palladium-catalyzed cross-coupling reactions with aryl iodides, tolerating various functional groups including hydroxy and free amino groups.
- Adak, Laksmikanta,Yoshikai, Naohiko
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experimental part
p. 7563 - 7568
(2011/11/12)
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- Nickel-catalyzed C-O activation of phenol derivatives with potassium heteroaryltrifluoroborates
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A general method based on nickel-catalyzed C-O activation of various phenol derivatives with potassium (hetero)aryltrifluoroborates has been developed. A large number of heterobiaryls can be easily obtained with yields up to 99% using methanesulfonate cross-coupling partners.
- Molander, Gary A.,Beaumard, Floriane
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supporting information; experimental part
p. 4022 - 4025
(2010/11/05)
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- The 1,3-diaminobenzene-derived aminophosphine palladium pincer complex {C6H3[NHP(piperidinyl)2]2Pd(Cl)} - A highly active Suzuki-Miyaura catalyst with excellent functional group tolerance
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The rapidly prepared 1,3-diaminobenzenederived aminophosphine pincer complex {C6H3 [NHP(piperidinyl)2] 2Pd(Cl)} (1) is an effective Suzuki catalyst with excellent functional group tolerance. Side-product formations, such as homocoupling, debromation or protodeboration have only rarely been detected and if so, were in all cases below the 5% level. The presented reaction protocol is universally applicable. Experimental observations indicate that palladium nanoparticles are the catalytically active form of 1.
- Bolliger, Jeanne L.,Frech, Christian M.
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experimental part
p. 1075 - 1080
(2010/06/17)
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- Palladium-catalyzed cross-coupling reaction of heteroaryltriolborates with aryl halides for synthesis of biaryls
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Cyclic triolborates possessing a heteroaromatic ring on the boron atom [ArB(OCH2)3CHCH3]M (M=K, Na, Li) were prepared in high yields from heteroarylboronic acids, 1,1,1-tris(hydroxymethyl)ethane (triol) and KOH or NaH. The corresponding lithium salts were synthesized from aryllithiums, B(OMe)3 and triol. They were air-stable white solids that were convenient for handling in air. High performance of these triolborates for metal-catalyzed bond-forming reactions was demonstrated in palladium-catalyzed cross-coupling reactions with haloarenes. Although the use of heteroarylboronic acids often results in very low yields due to competitive hydrolytic B-C bond cleavage with water under typical conditions using aqueous bases, triolborates possessing a 2-pyridyl, 3-pyridyl or 2-thiophenyl ring afforded biaryls in high yields at 50-120C in anhydrous DMF. There was a strong accelerating effect of CuI for reactions of 2-and 3-pyridylborate derivatives, whereas 2-thiophenyl derivatives reacted smoothly resulting in high yields in the absence of CuI.
- Yamamoto, Yasunori,Takizawa, Miho,Yu, Xiao-Qiang,Miyaura, Norio
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experimental part
p. 359 - 368
(2010/04/27)
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- Efficient diphosphane-based catalyst for the palladium-catalyzed suzuki cross-coupling reaction of 3-pyridylboronic acids
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A highly active catalyst system derived from PdCl2 and 2,2',6,6'- tetramethoxy-4,4'-bis(diphenylphosphanyl)-3,3'-bi- pyridine (P-Phos) has been developed for the Suzuki cross- coupling reaction of pyridylboronic acid with a variety of aryl halides in good to excellent yields, even in the presence of hindered and functional groups. In addition, P-Phos also exhibited high activity in the palladium-catalyzed Suzuki reaction of 2,6-dimethoxypyridylboronic acid in excellent yields with a fast rate. The steric and electronic effects of the P- Phos-palladium complex to this cross-coupling reaction were also discussed.
- Fu, Xing-Li,Wu, Lei-Lei,Fu, Hai-Yan,Chen, Hua,Li, Rui-Xiang
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experimental part
p. 2051 - 2054
(2009/09/06)
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- Highly efficient cyclopalladated ferrocenylimine catalyst for Suzuki cross-coupling reaction of 3-pyridylboronic pinacol ester with aryl halides
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The Suzuki cross-coupling reaction of 3-pyridylboronic pinacol ester with aryl iodides, bromides and chlorides was carried out in DMF/H2O (3/1, v/v) at 110 °C in the presence of cyclopalladated ferrocenylimine I and K2CO3 or CsCO3 (1.0 equiv.) without the protection of inert gas. By using this method the synthesis of 3-pyridyl biaryl compounds could be readily achieved.
- Zhang, Jinli,Zhao, Liang,Song, Maoping,Mak, Thomas C.W.,Wu, Yangjie
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p. 1301 - 1306
(2007/10/03)
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- Generation of 3-Pyridyl Biaryl Systems Via Palladium-Catalyzed Suzuki Cross-Couplings of Aryl Halides with 3-Pyridylboroxin
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The synthesis of 3-pyridyl biaryl systems can be readily achieved by means of palladium-catalyzed Suzuki cross-coupling reactions between aryl halides and 3-pyridyl-boroxin. A series of cross-couplings were conducted in order to investigate the scope and limitations of this protocol.
- Cioffi, Christopher L.,Spencer, William T.,Richards, Justin J.,Herr, R. Jason
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p. 2210 - 2212
(2007/10/03)
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- A CONVENIENT SYNTHESIS OF 3-ARYLPYRIDINES BY THE PALLADIUM CATALYZED COUPLING REACTION OF DIETHYL(3-PYRIDYL)BORANE WITH ARYL HALIDES
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The utilization of heteroarylborane to the preparation of a variety of 3-arylpyridines by the palladium catalyzed cross coupling reaction between diethyl(3-pyridyl)borane and aryl halides in the presence of bases is described.
- Ishikura, Minoru,Kamada, Machiko,Terashima, Masanao
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p. 265 - 268
(2007/10/02)
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