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A stable and easily prepared catalyst for the enantioselective reduction of ketones. Applications to multistep syntheses
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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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Kinetic resolution of 2-substituted-2,3-dihydrofurans by a palladium-catalyzed asymmetric Heck reaction
TL;DR: In this article, the kinetic resolution of 2-substituted-dihydrofurans via a palladium-catalyzed asymmetric Heck reaction was realized, providing optically active 2 -substitized-dhdrans and trans-2,5-disubstitized -dhddrans with an S factor up to 70.
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An enantioselective synthesis of the C3-C21 segment of the macrolide immunosuppressive agent FR252921.
Arun K. Ghosh,Samuel Rodriguez +1 more
TL;DR: An enantioselective synthesis of the C3-C21 segment of the novel immunosuppressant FR252921 is described, and key steps involved Curtius rearrangement and Horner-Wadsworth-Emmons olefination reactions.
Journal ArticleDOI
Enzymatic Kinetic Resolution of 2-Cyclohexen-1-ol Derivatives
TL;DR: Optically active (S)-2-cyclohexen-1-ol derivatives and their enantiomeric (R)-acetates have been obtained in high enantiomersic excesses by enzymatic kinetic acetylation catalyzed by lipase AK.
Journal ArticleDOI
Stereoselective Synthesis of the ABC Ring System of Aspterpenacids.
TL;DR: The successful construction of the key highly substituted ABC ring system in a stereoselective manner is reported.
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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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