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
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Oxazaborolidine als Katalysatoren für enantioselektive Cycloadditionen: Jetzt auch [2+2]!
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Asymmetric Synthesis of Naturally Occurring Spiroketals
B. Rama Raju,Anil K. Saikia +1 more
TL;DR: This article aims at reviewing the asymmetric synthesis of biologically active spiroketals for last 10 years (1998-2007).
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Oenothein B, dimeric hydrolysable tannin inhibiting HCV invasion from Oenothera erythrosepala.
Satoru Tamura,Gang-Ming Yang,Teruaki Koitabashi,Yoshiharu Matsuura,Yasumasa Komoda,Tomikazu Kawano,Nobutoshi Murakami +6 more
TL;DR: In this article, the envelope proteins of the hepatitis C virus (HCV), E1 and E2, have been revealed to be essential for invasion of HCV, and the authors were engaged in the search for the inhibitors against HCV invasion through the assay system using the model virus expressing recombinant HCV envelopes.
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Enantioselective borane reduction of prochiral ketones catalyzed by a chloro-containing chiral β-amino alcohol
TL;DR: A chloro-containing chiral β-amino alcohol (S)-2 amino alcohol, 3-(2-chlorophenyl)-1,1-diphenyl-1-propanol (1) was prepared from the related amino acid, which was synthesized via malonic ester method as mentioned in this paper.
Journal ArticleDOI
The B–H–B bridging interaction in B-substituted oxazaborolidine–borane complexes: a theoretical study
TL;DR: In this paper, ten oxazaborolidine-borane complexes, nine among them boron-substituted (B-R, R=CH3, CF3, and OCH3), are carefully analyzed using quantum-chemistry methods to determine their equilibrium geometries and the corresponding oxazabolidine−borane interaction energies.
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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