Journal ArticleDOI
A stable and easily prepared catalyst for the enantioselective reduction of ketones. Applications to multistep syntheses
Reads0
Chats0
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
More filters
Journal ArticleDOI
An Efficient Asymmetric Synthesis of Prostaglandin E1
TL;DR: An asymmetric total synthesis of Prostaglandin E1 (5) has been achieved in a two-component coupling process as discussed by the authors, where the key reaction step was a kinetic enzymatic resolution followed by an in situ inversion.
Journal ArticleDOI
Enantioselective Catalytic Borane Reductions of Achiral Ketones: Synthesis and Application Of New Catalysts Prepared from (S)-Tert-Leucine and (S)-Azetidinecarboxylic Acid
TL;DR: In this article, the reduction of prochiral ketones with borane in the presence of homochiral amino alcohols 1-3 as enantioselective catalysts afforded the corresponding secondary alcohols in moderate to high (69 to 99 %) optical yields.
Journal ArticleDOI
Enantioselective reduction of ketones catalysed by 1,3,2-oxazaborolidines prepared from phenylglycine
TL;DR: In this article, the reduction of linear alkyl methyl ketones with oxazaborolidines has been investigated and the best results reported so far regarding the reduction have been obtained for linear alkalkyl ketones.
Journal ArticleDOI
In Vitro Double Oxidation of n-Heptane with Direct Cofactor Regeneration
Christina Andrea Müller,Beneeta Akkapurathu,Till Winkler,Svenja Staudt,Werner Hummel,Harald Gröger,Harald Gröger,Ulrich Schwaneberg +7 more
TL;DR: A new strategy for the double oxidation of n-heptane is developed to enable a bio- catalytic resolution for the direct synthesis of heptan- A and (R)-heptanols in a one-pot reaction.
Journal ArticleDOI
Asymmetric synthesis of ferrocenylazido alcohols and their derivatization to novel chiral ferrocenyl-thiazoline ligands with C2-symmetry
TL;DR: In this article, the synthesis of chiral ferrocenyl-thiazoline ligands with C2-symmetry was described, which were obtained from (R)-2-azido-1-ferrocenylethanol 3 and diacyl chlorides.
References
More filters
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.
Related Papers (5)
Reduction of Carbonyl Compounds with Chiral Oxazaborolidine Catalysts: A New Paradigm for Enantioselective Catalysis and a Powerful New Synthetic Method.
E. J. Corey,Christopher J. Helal +1 more