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
Diastereoselective synthesis of 2,5-disubstituted tetrahydrofurans
TL;DR: A review focusing on synthetic methods allowing the preparation of 2,5-disubstituted tetrahydrofurans reported in the literature between 1993 and 2008 can be found in this paper.
Journal ArticleDOI
2-Azanorbornyl alcohols: very efficient ligands for ruthenium-catalyzed asymmetric transfer hydrogenation of aromatic ketones
Diego A. Alonso,Sofia J. M. Nordin,Peter Roth,Tibor Tarnai,Pher G. Andersson,Marc Thommen,Ulrich Pittelkow +6 more
TL;DR: 2-Azanorbornyl-derived amino alcohols were prepared and evaluated as ligands in the Ru(II)-catalyzed asymmetric transfer hydrogenation of aromatic ketones to improve selectivity and rate, and the structure of the ligand was optimized.
Journal ArticleDOI
Large scale preparation of versatile chiral auxiliaries derived from (S)-proline1
TL;DR: In this article, the synthesis of enantiomerically pure chiral auxiliaries based on (S)-proline and bearing sterically demanding side chains at the pyrrolidine moiety, such as the secondary amines (S), 3, 5 and 7 and the hydrazines(S)-6, is described on a molar scale.
Journal ArticleDOI
Enantioselective Reduction of Ketones and Imines Catalyzed by (CN‐Box)ReV–Oxo Complexes
TL;DR: The development and application of chiral, non-racemic Re(V)-oxo complexes to the enantioselective reduction of prochiral ketones is described and a tandem Meyer-Schuster rearrangement/reduction to access enantioenriched allylic alcohols is reported.
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