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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Concise total syntheses of (±)-mesembrane and (±)-crinane
TL;DR: A straightforward and unified strategy to access Amaryllidaceae alkaloids comprising a cis-3a-aryloctahydroindole scaffold with Eschenmoser-Claisen rearrangement of allylalcohol as a key step for the installation of all-carbon quaternary stereocenters present in these alkal steroids.
Journal ArticleDOI
Enantioselective Reduction of Ketones Catalyzed by Rare-Earth Metals Complexed with Phenoxy Modified Chiral Prolinols.
TL;DR: Enantioselective reduction of ketones and α,β-unsaturated ketones by pinacolborane (HBpin) has been well-established by using chiral rare-earth metal catalysts with phenoxy modified prolinols and a number of highly optically active alcohols were obtained.
Journal ArticleDOI
Chiral squaric prolinols: a new type of ligand for the asymmetric reduction of prochiral ketones by borane
Ji Zhang,Haibing Zhou,Shou-Mao Lü,Meiming Luo,Ru-Gang Xie,Michael C. K. Choi,Zhongyuan Zhou,Albert S. C. Chan,Teng-Kuei Yang +8 more
TL;DR: In this article, a series of chiral bifunctional squaric prolinol ligands, having N, S substituents at C(3) of the ring were synthesized and applied to the asymmetric borane reduction of prochiral ketones via an in situ formed chiral BORON heterocycle, affording secondary alcohols with high yields and excellent enantiomeric excesses.
Journal ArticleDOI
A facile synthesis of optically active lactones using benzyl-3,6-anhydro glucofuranoside as chiral auxiliary
TL;DR: In this article, a highly enantioselective synthesis of γ- and δ-lactones using an anhydrofuranoside derived from D-glucose as chiral auxiliary is described.
Journal ArticleDOI
Design and optimization of renin inhibitors: Orally bioavailable alkyl amines.
Colin M. Tice,Zhenrong Xu,Jing Yuan,Robert D. Simpson,Salvacion Cacatian,Patrick T. Flaherty,Wei Zhao,Joan Guo,Ishchenko Alexey,Suresh B. Singh,Zhongren Wu,Boyd B. Scott,Yuri Bukhtiyarov,Jennifer Berbaum,Jennifer M. Mason,Reshma Panemangalore,Maria Grazia Cappiello,Dominik N. Müller,Richard K. Harrison,Gerard McGeehan,Lawrence W. Dillard,Baldwin John J,David A. Claremon +22 more
TL;DR: Oral administration of lead compound 21l, with MW of 508 and IC(50) of 0.47nM, caused a sustained reduction in mean arterial blood pressure in a double transgenic rat model of hypertension.
References
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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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