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
Optisch aktive (β‐Oxoaldiminato)cobalt(II)‐Komplexe als Katalysatoren in der enantioselektiven Reduktion von Ketonen mit Natriumborhydrid
Journal ArticleDOI
Synthesis of chiral 1-ferrocenylaldols and 1-ferrocenyl-1,3-diols via asymmetric reductions
Angela Patti,Sonia Pedotti +1 more
TL;DR: In this article, the CBS-catalyzed reduction of 1-ferrocenyl-β-hydroxy-1-ketones, previously protected as acetates, was investigated, giving both the corresponding syn- and anti-1,3-diols in satisfactory enantiomeric purity.
Journal ArticleDOI
Amphidinolide B: total synthesis, structural investigation, and biological evaluation.
TL;DR: Key aspects of this work include the development of a practical, non-transition-metal-mediated method for the construction of the C13-C15 diene, the identification of α-chelation and dipole minimization models for diastereoselective methyl ketone aldol reactions, and the discovery of a spontaneous Horner-Wadsworth-Emmons macrocyclization strategy.
Journal ArticleDOI
Screening of ligands in the asymmetric metallocenethiolatocopper(I)-catalyzed allylic substitution with Grignard reagents
TL;DR: In this paper, a screening of metallocenethiolate ligands for copper(I)-catalyzed substitution of allylic acetates with Grignard reagents has been carried out.
Journal ArticleDOI
Enantioselective Borohydride Reduction of Ketones Catalyzed by Optically Active Cobalt(II) Complexes: Achievement of High Enantioselection by Modified Borohydrides with Furfuryl Alcohol Derivatives.
TL;DR: In this paper, the enantioselective borohydride reduction of ketones catalyzed by optically active (β-oxoaldiminato) cobalt(II) complexes was remarkably improved by using the borhydride which was modified with furfuryl alcohol dervatives and ethanol.
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