Microbial hydroxylation of 2-cycloalkylbenoxazoles. Part II. Determination of product structures and enhancement of enantiomeric excess
摘要:
The determinations of product structures obtained in the microbial hydroxylations of various 2-cycloalkyl-1, 3-benzoxazoles using Cunninghamella blakesleeana DSM 1906 and Bacillus megaterium DSM 32 are described. The initially low e.e. of 3-(benz-1, 3-oxazol-2-yl)cyclopentan-1-ol 6, 2-(benz-1, 3-oxazol-2-yl)cyclohexan-1-ol 14 and 4-(2-bent-1, 3-oxazol-2-yl)cycloheptan-1-ol 21 can be enhanced to 98% using lipase catalyzed resolution.
A General Approach to Substituted Benzimidazoles and Benzoxazoles
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Heterogeneous Palladium‐Catalyzed Hydrogen‐Transfer with Primary Amines
作者:Marianna Pizzetti、Elisa De Luca、Elena Petricci、Andrea Porcheddu、Maurizio Taddei
DOI:10.1002/adsc.201200253
日期:2012.9.17
employed. Primaryamines are the most suitable reagents for the atom economy of the overall process that resulted to be general as several different substitutedbenzimidazoles were obtained in good yield. Benzoxazoles can be also prepared starting from primaryamines and o‐aminophenol. The reaction is also highly selective as no (poly)‐alkylated phenylenediamines or cross‐contaminated benzimidazoles are
Organocatalyzed, Visible-Light Photoredox-Mediated, One-Pot Minisci Reaction Using Carboxylic Acids via <i>N</i>-(Acyloxy)phthalimides
作者:Trevor C. Sherwood、Ning Li、Aliza N. Yazdani、T. G. Murali Dhar
DOI:10.1021/acs.joc.8b00205
日期:2018.3.2
one-pot Minisci reaction has been developed using visible light, an organic photocatalyst, and carboxylic acids as radical precursors via the intermediacy of in situ-generated N-(acyloxy)phthalimides. The conditions employed are mild, demonstrate a high degree of functional group tolerance, and do not require a large excess of the carboxylic acid reactant. As a result, this reaction can be applied to
Iron(0)-Catalyzed Transfer Hydrogenative Condensation of Nitroarenes with Alcohols: A Straightforward Approach to Benzoxazoles, Benzothiazoles, and Benzimidazoles
作者:Ramachandra Reddy Putta、Simin Chun、Seung Hyun Choi、Seok Beom Lee、Dong-Chan Oh、Suckchang Hong
DOI:10.1021/acs.joc.0c02191
日期:2020.12.4
the redox condensation of o-hydroxynitrobenzene with alcohol, leading to the formation of benzoxazole derivatives. A wide range of 2-substituted benzoxazoles were synthesized in good to excellent yields without the addition of an external redox agent. A series of control experiments provided a plausible mechanism. Furthermore, the reaction system was successfully extended to the synthesis of benzothiazoles
Gold nanoparticles supported on titanium dioxide: an efficient catalyst for highly selective synthesis of benzoxazoles and benzimidazoles
作者:Lin Tang、Xuefeng Guo、Yu Yang、Zhenggen Zha、Zhiyong Wang
DOI:10.1039/c4cc01822b
日期:——
A highly efficient and selective reaction for the synthesis of 2-substitutedbenzoxazoles and benzimidazoles catalyzed by Au/TiO2 has been developed via two hydrogen-transfer processes. This reaction has a good tolerance to air and water, a wide substrate scope, and represents a new avenue for practical C-N and C-O bond formation. More importantly, no additional additives, oxidants and reductants are
AgPd Nanoparticles Deposited on WO<sub>2.72</sub> Nanorods as an Efficient Catalyst for One-Pot Conversion of Nitrophenol/Nitroacetophenone into Benzoxazole/Quinazoline
作者:Chao Yu、Xuefeng Guo、Zheng Xi、Michelle Muzzio、Zhouyang Yin、Bo Shen、Junrui Li、Christopher T. Seto、Shouheng Sun
DOI:10.1021/jacs.7b01983
日期:2017.4.26
acid, 2-nitrophenol, and aldehydes into benzoxazoles in near quantitative yields under mild conditions. The catalysis can also be extended to the one-pot reactions of ammonium formate, 2-nitroacetophenone, and aldehyde for high yield syntheses of quinazolines. Our studies demonstrate a new catalyst design to achieve a green chemistry approach to one-pot reactions for the syntheses of benzoxazoles and quinazolines