Journal ArticleDOI
A stable and easily prepared catalyst for the enantioselective reduction of ketones. Applications to multistep syntheses
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TLDR
In this paper, the authors described a new method for the catalytic enantioselective reduction of ketones to chiral secondary alcohols, where the stoichiometric reagent in the reduction is borane and the catalyst is a chiral oxazaborolidine such as 1 (0.05-0.1 molfmol of ketone).Abstract:
We have recently described a new method for the catalytic enantioselective reduction of ketones to chiral secondary alcohols.' The stoichiometric reagent in the reduction is borane (usually 0.6 molfmol of ketone), and the catalyst is a chiral oxazaborolidine such as 1 (0.05-0.1 molfmol of ketone). Excellent enantioselectivities, easy recoverability of the chiral catalyst predecessor, near quantitative yields, short reaction times (a few minutes at 23 \"C), and predictability of the absolute configuration of the product contribute to the outstanding utility of this (CBS') process. This paper reports several subsequent developments in this area with respect to improved practicality and important applications. In contrast to 1 which is both air and moisture sensitive, the B-methylated oxazaborolidine 2 can be stored in closed containers at room temperature and weighed or transferred in air. Catalyst 2 is also much more easily prepared than 1. Reaction of (S)-read more
Citations
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A Simple Synthesis of (S)-α,α-Diaryl-2-pyrrolidinemethanols
TL;DR: The enantiopure α,α-diaryl-2 pyrrolidinemethanols and their derivatives represent an important class of chiral auxiliaries for asymmetric synthesis, including reagents for the Corey-Bakshi-Shibata reducer as mentioned in this paper.
Journal ArticleDOI
Stereoselective Borane Reduction of Acetophenone using 1,3,2-Oxazaborolidine Derived from (R)-4-(Diphenylhydroxymethyl)-1,3-Thiazolidine
Monique Calmes,Françoise Escale +1 more
TL;DR: A chiral 1, 3, 2-oxazaborolidine derived from (R)-4-(diphenylhydroxymethyl)-l, 3-thiazolidine has been synthesized and its efficiency in the asymmetric reduction of acetophenone by borane has been investigated.
Journal ArticleDOI
Stereoselective Synthesis of 3-butylphtalide via CBS Catalytic Reduction
TL;DR: Optically active 3-butylphtalide of high enantiomeric excesses was synthesized from the reduction of o-pentanoylbenzoic ester with borane using B-methyloxyoxazaborolidine (1b) as the chiral catalyst as mentioned in this paper.
Journal ArticleDOI
A DFT study of the enantioselective reduction of oxime ethers promoted by chiral spiroborate esters
Zhibo Qu,Xiaolan Chen,Donghui Wei,Diandian Ke,Ling-Bo Qu,Ling-Bo Qu,Jinwei Yuan,Yunliang Bai,Fujun Wang,Yufen Zhao,Yufen Zhao +10 more
TL;DR: Wang et al. as discussed by the authors proposed a method to solve the problem of artificial neural networks in Henan Province (Innovation Specialist Projects) of China, Henan province.
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Molybdenum and Molybdenum-Containing Enzymes
TL;DR: In this article, a few moment to read a book even only few pages is recommended, even if it is not obligation and force for everybody, reading book becomes a choice of your different characteristics.
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