Asymmetric reduction of nitroalkenes with baker's yeast
摘要:
Various alpha,beta -disubstituted and trisubstituted nitroalkenes were chemoselectively reduced with baker's yeast to the corresponding nitroalkanes. Stereoselectivities of the reduction of alpha,beta -disubstituted nitroalkenes were modest to low, and e.e.s up to 52% were obtained. Trisubstituted nitroalkenes could be reduced to the corresponding nitroalkanes with excellent enantioselectivities, moderate diastereoselectivities and in good yield. (C) 2001 Elsevier Science Ltd. All rights reserved.
Asymmetric reduction of nitroalkenes with baker's yeast
摘要:
Various alpha,beta -disubstituted and trisubstituted nitroalkenes were chemoselectively reduced with baker's yeast to the corresponding nitroalkanes. Stereoselectivities of the reduction of alpha,beta -disubstituted nitroalkenes were modest to low, and e.e.s up to 52% were obtained. Trisubstituted nitroalkenes could be reduced to the corresponding nitroalkanes with excellent enantioselectivities, moderate diastereoselectivities and in good yield. (C) 2001 Elsevier Science Ltd. All rights reserved.
A formal, two-step anti-Markovnikov addition of H2O to diastereomeric mixtures of trisubstituted olefins towards enantio- and diastereomerically highly-enriched alcohols is demonstrated. This method relies on the syn-specific Shi-epoxidation, followed by a titanocene-catalyzed epoxide hydrosilylation featuring a directional-isomerization step to converge the diastereomeric mixtures of epoxides into
证明了H 2 O 向三取代烯烃的非对映体混合物中向对映体和非对映体高度富集的醇进行正式的两步反马尔可夫尼科夫加成。该方法依赖于顺式特定的Shi环氧化,然后是二茂钛催化的环氧化物氢化硅烷化,其特征在于定向异构化步骤,将环氧化物的非对映异构体混合物聚合成单一立体异构体。
Asymmetric reduction of nitroalkenes with baker's yeast
作者:Yasushi Kawai、Yoshikazu Inaba、Norihiro Tokitoh
DOI:10.1016/s0957-4166(01)00029-5
日期:2001.2
Various alpha,beta -disubstituted and trisubstituted nitroalkenes were chemoselectively reduced with baker's yeast to the corresponding nitroalkanes. Stereoselectivities of the reduction of alpha,beta -disubstituted nitroalkenes were modest to low, and e.e.s up to 52% were obtained. Trisubstituted nitroalkenes could be reduced to the corresponding nitroalkanes with excellent enantioselectivities, moderate diastereoselectivities and in good yield. (C) 2001 Elsevier Science Ltd. All rights reserved.