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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Stereoselective synthesis of aryl γ,δ-unsaturated β-hydroxyesters by ketoreductases
TL;DR: In this article, the biocatalytic reduction of aryl γ, δ -unsaturated- β -ketoesters was evaluated utilizing 24 different commercially available ketoreductases.
Journal ArticleDOI
A Unified Strategy for the Asymmetric Synthesis of Highly Substituted 1,2-Amino Alcohols Leading to Highly Substituted Bisoxazoline Ligands.
Bijay Shrestha,Brennan T. Rose,Casey L. Olen,Aaron Roth,Adon C. Kwong,Yang Wang,Scott E. Denmark +6 more
TL;DR: In this article, a general procedure for the asymmetric synthesis of highly substituted 1,2-amino alcohols in high yield and diastereoselectivity is described.
Journal ArticleDOI
Anchoring substitution in acyclic 1,3-amino alcohols. Asymmetric reductions with chiral modifications of lithium aluminum hydride and borane.
TL;DR: In this article, the absolute configuration of the chiral ligands was determined via X-ray analysis of the ammonium (S)-(+)-10-camphorsulfonate salt 8, derived from 2.
Journal ArticleDOI
Enzyme-catalyzed asymmetric synthesis of optically active (R)- and (S)-ethyl -4-phenyl-4-hydroxybutyrate with microbial cells
TL;DR: The highly enantioselective bioreductions provide simple routes to optically active γ-hydroxyl acid esters that are useful pharmaceutical intermediates and versatile chiral building blocks.
Journal ArticleDOI
New functional chiral P-based ligands and application in ruthenium-catalyzed enantioselective transfer hydrogenation of ketones
TL;DR: In this paper, a series of chiral β-amino alcohols were synthesized by chiral amines with regioselective ring opening of (S)-propylene oxide or reaction with (S-(+)-2-hydroxypropyl p-toluenesulfonate by a straightforward method.
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Book
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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