- Conformation of hydrogen-bonded dimeric o-methyl-substituted benzoic acids
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Molecules of 2,4-dimethyl-benzoic acid, C9H10O2, form typical centrosymmetric hydrogen-bonded dimers. The carboxyl group is twisted with respect to the benzene ring and the methyl group in the ortho position shows evasive in-plane splaying. The relation b
- Glinski, Marek,Wilczkowska, Ewa,Madura, Izabela D.,Zachara, Janusz
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- Heterogeneous vanadium-catalyzed oxidative cleavage of olefins for sustainable synthesis of carboxylic acids
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The development of green and sustainable processes to synthesize active pharmaceutical ingredients and key starting materials is a priority for the pharmaceutical industry. A green and sustainable protocol for the oxidative cleavage of olefins to produce pharmaceutically and biologically valuable carboxylic acids is achieved. The developed protocol involves 70% aq. TBHP as an oxidant over a heterogeneous vanadium catalyst system. Notably, the synthesis of industrially important azelaic acid from various renewable vegetable oils is accomplished. The catalyst could be recycled for up to 5 cycles without significant loss in yield and the protocol was successfully demonstrated at the gram-scale.
- Upadhyay, Rahul,Rana, Rohit,Sood, Aakriti,Singh, Vikash,Kumar, Rahul,Srivastava, Vimal Chandra,Maurya, Sushil K.
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supporting information
p. 5430 - 5433
(2021/06/09)
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- Carboxylation of sodium arylsulfinates with CO2over mesoporous K-Cu-20TiO2
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A mesoporous ternary metal oxide (K-Cu-20TiO2) from a simple sol-gel method was prepared to catalyze heterogeneously the carboxylation reaction of various sodium arylsulfinates under atmospheric carbon dioxide. The catalyst showed excellent selectivity and good functional group tolerance to carboxylation recycle. The oxidation state of active copper(i) by characterization using FTIR, XRD, TG, XPS and TEM techniques proved to be efficacious to conduct atom economical reactions.
- Chen, Lei,Chen, Yanjiao,Dai, Xuan,Peng, Xinhua,Wu, Tao,Zhang, Wenwei
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p. 772 - 776
(2022/01/22)
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- Isotruxene-based porous polymers as efficient and recyclable photocatalysts for visible-light induced metal-free oxidative organic transformations
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Two new isotruxene-based porous polymers were prepared and demonstrated to be highly efficient, metal-free heterogeneous photocatalysts for oxidative transformations using air as the mild oxidant under visible-light irradiation. Both catalysts show excellent recyclability. In addition, the reactions can be performed in water, further indicating the greenness of this method. This journal is
- Zhang, Haowen,Zhang, Xiao,Zheng, Ying,Zhou, Cen
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supporting information
p. 8878 - 8885
(2021/11/27)
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- Dehydrogenation of Alcohols to Carboxylic Acid Catalyzed by in Situ-Generated Facial Ruthenium- CPP Complex
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A selective catalytic system for the dehydrogenation of primary alcohols to carboxylic acids using a facial ruthenium complex generated in situ from the [Ru(COD)Cl2]n and a hybrid N-heterocyclic carbene (NHC)-phosphine-phosphine ligand (CPP) has been first reported. The facial coordination model was unveiled by NMR analysis of the reaction mixture. Such a fac-ruthenium catalyst system exhibited high catalytic activity and stability, and a high turnover number of 20 000 could be achieved with catalyst loading as low as 0.002 mol %. The exceedingly high catalyst stability was tentatively attributed to both the anchoring role of NHC and the hemi-lability of phosphines. The catalytic system also features a wide substrate scope. In particular, the facial coordination of CPP ligands was found to be beneficial for sterically hindered alcohols, and ortho-substituted benzylic alcohols and bulky adamantanyl methanol as well as cholesterol were all found to be viable dehydrogenation substrates.
- Liu, Hui-Min,Jian, Lei,Li, Chao,Zhang, Chun-Chun,Fu, Hai-Yan,Zheng, Xue-Li,Chen, Hua,Li, Rui-Xiang
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p. 9151 - 9160
(2019/08/12)
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- Magnetic crosslinked copoly(ionic liquid) nanohydrogel supported palladium nanoparticles as efficient catalysts for the selective aerobic oxidation of alcohols
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Nowadays it is still a great sustainable processes challenge to produce efficient, selective and easy magnetic recovery and recycling catalysts for oxidation of alcohols using air as the oxidant. In this work, a new magnetic nanohydrogel comprising [DABCO-allyl][Br] ionic liquid, allyl alcohol and N,N’-methylenebis(acrylamide) is used for stabilization of small and highly uniform palladium nanoparticles of 3–4 nm size MXCPILNHG@Pd. This material has been characterized by Fourier-transform infrared spectroscopy (FTIR), atomic adsorption spectroscopy (AAS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), SEM-Map, energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectra (XPS), vibrating-sample magnetometer (VSM) and dynamic light scattering (DLS). According to optimization of cross-linking degree and ratio of DABCO-IL, MXCPILNHG-2@Pd is found as a highly selective catalyst in oxidations of primary alcohols to the corresponding aldehydes in toluene and to acids in water. Furthermore, secondary alcohols were reacted efficiently to the corresponding ketones in both toluene and water. Catalyst is magnetically recovered and recycled for several times in both toluene and water and the reused catalysts are characterized by TEM and XPS.
- Gholinejad, Mohammad,Afrasi, Mahmoud,Nikfarjam, Nasser,Nájera, Carmen
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p. 185 - 195
(2018/07/14)
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- Method for preparing aromatic acid by direct carboxylation of CO2
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The invention discloses a method for preparing aromatic acid by direct carboxylation of CO2. The method comprises the following steps: (1) adding aromatic hydrocarbon, organic alkali and lewis acid into a high pressure reaction kettle under an inert gas atmosphere, then feeding CO2 gas into the high pressure reaction kettle for reaction, and obtaining reaction liquid with aromatic acid at the endof the reaction; (2) adding water into the reaction liquid obtained in the step (1), then extracting the aromatic acid in the reaction liquid with an extracting agent to enable the aromatic acid in the reaction liquid to enter an extracting phase, separating the extracting phase from raffinate, and concentrating the extracting phase to obtain the aromatic acid. According to the method, complicatedpreparation of ionic liquid is avoided, and organic alkali is timely neutralized with halogen hydride produced by the reaction, so that the balance moves rightwards; at the end of the reaction, the organic alkali also can be recycled through alkali treatment. The method has the advantages of simple operation, mild conditions, green process, low cost and the like, and is expected to be applied toindustrial production.
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Paragraph 0047; 0048; 0050
(2018/05/16)
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- Iodine-catalyzed oxidative C-C bond cleavage for benzoic acids and benzamides from alkyl aryl ketones
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Iodine-catalyzed oxidative C-C bond cleavage has been performed for the facile synthesis of both benzoic acids and benzamides from readily available alkyl aryl ketones. Additionally benzylidene acetones and phenylacetylenes were also converted to the corresponding aromatic acids under the same conditions. This approach features the use of inexpensive iodine as a catalyst, broad substrate scope and open air conditions.
- Sathyanarayana, Pochampalli,Upare, Atul,Ravi, Owk,Muktapuram, Prathap Reddy,Bathula, Surendar Reddy
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p. 22749 - 22753
(2016/03/15)
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- Copper catalyzed oxygen assisted C(CNOH)-C(alkyl) bond cleavage: A facile conversion of aryl/aralkyl/vinyl ketones to aromatic acids
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A novel copper-catalyzed aerobic oxidative C(NOH)-C(alkyl) bond cleavage reaction of aryl/aralkyl/vinyl ketones for the synthesis of aromatic/acrylic acids is described. A series of ketones having aryl/aralkyl/vinyl at the one end and methyl to any higher alkyl at the other end can be selectively cleaved and converted into the corresponding acids via oxime intermediates.
- Sathyanarayana, Pochampalli,Ravi, Owk,Muktapuram, Prathap Reddy,Bathula, Surendar Reddy
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supporting information
p. 9681 - 9685
(2015/09/28)
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- Copper(I)-Catalyzed Desulfinative Carboxylation of Sodium Sulfinates using Carbon Dioxide
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A copper(I)-catalyzed desulfinative carboxylation of sodium sulfinates using carbon dioxide has been developed. This reaction showed wide functional group tolerance. A series of sodium aryl- and alkenylsulfinates could be converted into the corresponding carboxylic acids in good to excellent yields. Additionally, the reaction mechanism was studied by in situ NMR analysis and isotopic labeling experiments.
- Sun, Song,Yu, Jin-Tao,Jiang, Yan,Cheng, Jiang
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supporting information
p. 2022 - 2026
(2015/06/23)
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- Inclusion complex containing epoxy resin composition for semiconductor encapsulation
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The invention is an epoxy resin composition for sealing a semiconductor, including (A) an epoxy resin and (B) a clathrate complex. The clathrate complex is one of (b1) an aromatic carboxylic acid compound, and (b2) at least one imidazole compound represented by formula (II): wherein R2 represents a hydrogen atom, C1-C10 alkyl group, phenyl group, benzyl group or cyanoethyl group, and R3 to R5 represent a hydrogen atom, nitro group, halogen atom, C1-C20 alkyl group, phenyl group, benzyl group, hydroxymethyl group or C1-C20 acyl group. The composition has improved storage stability, retains flowability when sealing, and achieves an effective curing rate applicable for sealing delicate semiconductors.
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- Series of structural and functional models for the ES (enzyme-substrate) complex of the Co(II)-containing quercetin 2,3-dioxygenase
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A series of mononuclear CoII-flavonolate complexes [Co IILR(fla)] (LRH = 2-{[bis(pyridin-2-ylmethyl) amino]methyl}-p/m-R-benzoic acid; R = p-OMe (1), p-Me (2), m-Br (4), and m-NO2 (5); fla = flavonolate) were designed and synthesized as structural and functional models for the ES (enzyme-substrate) complexes to mimic the active site of the Co(II)-containing quercetin 2,3-dioxygenase (Co-2,3-QD). The metal center Co(II) ion in each complex shows a similar distorted octahedral geometry. The model complexes display high enzyme-type dioxygenation reactivity (oxidative O-heterocyclic ring opening of the coordinated substrate flavonolate) at low temperature, presumably due to the attached carboxylate group in the ligands. The reactivity exhibits a substituent group dependent order of -OMe (1) > -Me (2) > -H (3)14b > -Br (4) > -NO2 (5), and the Hammett plot is linear (ρ = -0.78). This can be explained as the electronic nature of the substituent group in the ligands may influence the conformation and redox potential of the bound flavonolate and finally bring different reactivity. The structures, properties, and reactivity of the model complexes show some dependence on the substituent group in the supporting model ligands, and there is some relationship among them. This study is the first example of a series of structural and functional ES models of Co-2,3-QD, with focus on the effects of the electronic nature of substituted groups and the carboxylate group of the ligands to the dioxygenation reactivity, that will provide important insights into the structure-property-reactivity relationship and the catalytic role of Co-2,3-QD.
- Sun, Ying-Ji,Huang, Qian-Qian,Zhang, Jian-Jun
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supporting information
p. 2932 - 2942
(2014/04/03)
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- Direct carboxylation of simple arenes with CO2 through a rhodium-catalyzed C-H bond activation
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Direct carboxylation of simple arenes under atmospheric pressure of CO2 is achieved through a rhodium-catalyzed C-H bond activation without the assistance of a directing group. Various arenes such as benzene, toluene, xylene, electron-rich or electron-deficient benzene derivatives, and heteroaromatics are directly carboxylated with high TONs. This journal is
- Suga, Takuya,Mizuno, Hajime,Takaya, Jun,Iwasawa, Nobuharu
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supporting information
p. 14360 - 14363
(2015/02/19)
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- Method for estimating SN1 rate constants: Solvolytic reactivity of benzoates
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Nucleofugalities of pentafluorobenzoate (PFB) and 2,4,6-trifluorobenzoate (TFB) leaving groups have been derived from the solvolysis rate constants of X,Y-substituted benzhydryl PFBs and TFBs measured in a series of aqueous solvents, by applying the LFER equation: log k = sf(Ef + Nf). The heterolysis rate constants of dianisylmethyl PFB and TFB, and those determined for 10 more dianisylmethyl benzoates in aqueous ethanol, constitute a set of reference benzoates whose experimental ΔG ? have been correlated with the ΔH? (calculated by PCM quantum-chemical method) of the model epoxy ring formation. Because of the excellent correlation (r = 0.997), the method for calculating the nucleofugalities of substituted benzoate LGs have been established, ultimately providing a method for determination of the SN1 reactivity for any benzoate in a given solvent. Using the ΔG? vs ΔH? correlation, and taking sf based on similarity, the nucleofugality parameters for about 70 benzoates have been determined in 90%, 80%, and 70% aqueous ethanol. The calculated intrinsic barriers for substituted benzoate leaving groups show that substrates producing more stabilized LGs proceed over lower intrinsic barriers. Substituents on the phenyl ring affect the solvolysis rate of benzhydryl benzoates by both field and inductive effects.
- Matic, Mirela,Denegri, Bernard,Kronja, Olga
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supporting information
p. 8986 - 8998,13
(2012/12/12)
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- Direct carboxylation of arenes and halobenzenes with CO2 by the combined use of AlBr3 and R3SiCl
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The Lewis acid-mediated direct carboxylation of aromatic compounds with CO2 is efficiently promoted by the addition of silyl chlorides bearing three alkyl and/or aryl substituents in total on the silicon atom. Thus, toluene, xylenes, mesitylene, and some other alkylbenzenes are treated with a 1:1 mixture of AlBr3 and Ph3SiCl in neat substrates under CO2 pressure (3.0 MPa) at room temperature, to give the corresponding carboxylic acids in 60-97% yields, based on AlBr3. Polycyclic arenes, including naphthalene, phenanthrene, and biphenyl, are regioselectively carboxylated in 91-98% yields with the aid of 1 molar equiv of AlBr3 and Ph3SiCl in an appropriate solvent, chosen from benzene, chlorobenzene, and fluorobenzene. These solvents, as well as bromobenzene, resist carboxylation; however, they are also carboxylated in moderate yields when treated with a 1:5 mixture of AlBr3 and iPrSiCl at elevated temperatures. The FT-IR spectrum of a mixture prepared by exposing a suspension of AlBr3 and Ph3SiCl in cyclohexane to CO 2 exhibits an absorption band around 1650 cm-1, assigned to the C=O stretching vibration of a species consisting of CO2, AlBr3, and Ph3SiCl, which suggests that the silyl chlorides activate CO2 in cooperation with AlBr3. 1H NMR analysis of unworked-up reaction mixtures reveals that the products merge as aluminum carboxylates. The mass balance concerning silicon indicates that the silyl chlorides are recycled during the reaction sequence. On the basis of these observations, a feasible mechanism is proposed for the present carboxylation.
- Nemoto, Koji,Yoshida, Hiroki,Egusa, Naoki,Morohashi, Naoya,Hattori, Tetsutaro
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experimental part
p. 7855 - 7862
(2011/02/21)
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- Beneficial effect of TMSCl in the Lewis acid-mediated carboxylation of aromatic compounds with carbon dioxide
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The Lewis acid-mediated carboxylation of aromatic compounds with CO 2 is significantly promoted by the addition of a large excess of chlorotrimethylsilane (TMSCl) to give arylcarboxylic acids in good to excellent yields. Copyright
- Nemoto, Koji,Yoshida, Hiroki,Suzuki, Yutaka,Morohashi, Naoya,Hattori, Tetsutaro
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p. 820 - 821
(2007/10/03)
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- Aerobic oxidation of trimethylbenzenes catalyzed by N,N′,N″-trihydroxyisocyanuric acid (THICA) as a key catalyst
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The oxidation of trimethylbenzenes was examined with air or O2 using N,N′,N″-trihydroxyisocyanuric acid (THICA) as a key catalyst. Thus, 1,2,3-, 1,2,4-, and 1,3,5-trimethylbenzenes under air (20 atm) in the presence of THICA (5 mol %), Co(OAc)2 (0.5 mol %), Mn(OAc)2, and ZrO(OAc)2 at 150 °C were oxidized to the corresponding benzenetricarboxylic acids in good yields (81-97%). In the aerobic oxidation of 1,2,4-trimethylbenzene by the THICA/Co(II)/Mn(II) system, remarkable acceleration was observed by adding a very small amount of ZrO(OAc)2 to the reaction system to form 1,2,4-benzenetricarboxylic acid in excellent yield (97%). In contrast, no considerable addition effect was observed in the oxidation of 1,3,5-trimethylbenzene. This aerobic oxidation by the present catalytic system provides an economical and environmentally benign direct method to benzenetricarboxylic acids, which are very important polymer materials.
- Hirai, Naruhisa,Tatsukawa, Yoshinobu,Kameda, Michiko,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 6695 - 6699
(2007/10/03)
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- An efficient Pd(II)-based catalyst system for carboxylation of aromatic C-H bond by addition of a phosphenium salt
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Addition of a phosphenium dramatically improved the reaction yields in the carboxylation of arenes by formic acid catalyzed by Pd(II). Control experiments revealed that the majority of the phosphenium triflate was converted to a mixed anhydride of phosphonic acid and formic acid (7), which however did not substitute for the phosphenium to improve the reaction yield.
- Sakakibara, Ken,Yamashita, Makoto,Nozaki, Kyoko
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p. 959 - 962
(2007/10/03)
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- Process for preparing an aryl formate and an aromatic carboxylic acid
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A method of producing aryl formate by oxidizing the aromatic aldehyde in an organic solvent having substantially no ability of dissolving water with performic acid generated in situ in the reaction system from the reaction between formic acid and hydrogen peroxide. Optionally the method comprises a second step for decomposing the aryl formate to a phenol compound. This second step may be performed by thermally decomposing the aryl formate to the phenol compound and carbon monoxide at 110 to 350°C in liquid phase in the presence of an alkali metal compound.
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- Efficient chemoselective carboxylation of aromatics to arylcarboxylic acids with a superelectrophilically activated carbon dioxide-Al2Cl6/Al system
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Aromatic carboxylic acids are obtained in good to excellent yield essentially free of diaryl ketones by carboxylation of aromatics with a carbon dioxide-Al2Cl6/Al system at moderate temperatures (20-80°C). To optimize reaction condit
- Olah, George A.,Toeroek, Bela,Joschek, Jens P.,Bucsi, Imre,Esteves, Pierre M.,Rasul, Golam,Prakash, G. K. Surya
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p. 11379 - 11391
(2007/10/03)
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- An alternative channel of reductive condensation of trichloromethylarenes with hydrazines
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The reductive condensation of trichloromethylarenes with hydrazines can proceed without intermediate formation of pyridinium salts and without participation of pyridine in the reduction act. Variants of reductive condensation using hydrazines as reducting agents and α-chlorobenzylhydrazines and hydrazonoyl chlorides, nitrite imines, or hydrazonoylpyridinium salts as intermediates are considered. α-Chlorobenzylhydrazines and hydrazonoyl chlorides are shown to be the most probable intermediates.
- Belen'kii,Luiksaar,Chuvylkin,Krayushkin
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p. 886 - 893
(2007/10/03)
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- Aromatic Spiranes XX [1]: Syntheses of Dimethylsubstituted 2-Carboxymethyl-indan-1-ones and Benzylchlorides as Synthones for Syntheses of di- to tetramethylsubstituted Spirobiindandiones
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The isomeric dimethyl methylbenzoates 5, obtained from the bromides via Grignard reactions with dimethylcarbonate, were reduced with LiAlH4 to the hydroxymethyl derivatives 6. The latter were then transformed both to the benzylchlorides 7 (with SOCl2) and to the aldehydes 8 (with pyridinium chlorochromate). Knoevenagel-Doebner reaction of 8 afforded the acrylic acids 9 which (after hydrogenation to 11) were cyclized to the desired indanones 12 with polyphosphoric acid. On the other hand, 12c and 12e were prepared from dimethyl 3-chloropropiophenone (14) by warming with sulfuric acid. After NaH-catalyzed reaction with dimethylcarbonate, the indanones 12 gave the ketoesters 15 which then could be hydrogenated to the indanes 16. All reactions proceeded with satisfactory to excellent yields (60-90%).
- Neudeck
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p. 185 - 200
(2007/10/03)
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- Pd-Catalyzed Regio- and Stereo-selective Carboxylation of Cycloalkanes with CO
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The reactions of cycloalkanes with CO via the C-H bond activation by Pd(OAc)2 catalyst have been found to proceed regio- and stereo-selectively to give corresponding carboxylic acids.The reactivity of C-H bonds of cycloalkanes decreases in the order: tert- > sec- > prim-carbon, and the stereochemistry of the substitutents on the main products is all equatorial.
- Satoh, Ko-ichi,Watanabe, Jun,Takaki, Ken,Fujiwara, Yuzo
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p. 1433 - 1436
(2007/10/02)
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- SYNTHETIC STUDIES ON NOGALAMYCIN CONGENERS ; TOTAL SYNTHESES OF (+)-NOGARENE, (+)-7-DEOXYNOGAROL, AND (+)-7-CON-O-METHYLNOGAROL
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According to the retrosynthetic perspective, the title total syntheses were accomplished by employing the regioselective Diels-Alder reactions of the (+)-naphthoquinone (5), the CDEF-ring system of nogalamycin congeners, with various structural types of dienes (8, 16, and 26).The highly functionalized dienes (16 and 26) incorporating all the functionalities present in the A-rings of (+)-7-deoxynogarol (3) and (+)-7-con-O-methylnogarol (2), were prepared efficiently by way of the 1,4-cyclohexadiene and 2-cyclohexanone derivatives (6 and 21), respectively.Reaction mechanism of the key Diels-Alder reaction was also discussed in terms of its stereoselectivity.
- Kawasaki, Motoji,Matsuda, Fuyuhiko,Terashima, Shiro
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p. 5727 - 5744
(2007/10/02)
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- Aromatic Substitution. 46. Methyl (Ethyl) Thio(Dithio)carboxylation of Aromatics with S-Methyl (S-Ethyl) Thiocarboxonium and Dithiocarboxonium Fluoroantimonates
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S-Methyl(S-ethyl)thio(dithio)carboxinium ions were prepared by reacting methyl(ethyl) fluoride-antimony pentafluoride with carbonyl sulfide (carbon disulfide) and studied with 1H and 13C NMR spectroscopy.The ions were subsequently used in the novel carboxylation reaction of arenes to S-methyl (S-ethyl) thio(dithio)benzoates.The method was also found to be adaptable to the carboxylation of polystyrene to poly(styrenecarboxylic acid) without degradation of the polymer backbone.
- Olah, George A.,Bruce, Mark R.,Clouet, Francoise L.
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p. 438 - 442
(2007/10/02)
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