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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
Citations
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Chemoselective Reduction and Alkylation of Carbonyl Functions Using Phosphonium Salts as an in Situ Protecting Groups.
Reiya Ohta,Hiromichi Fujioka +1 more
TL;DR: This account discusses the strategy and applications of the in situ protection method using phosphonium salts and recent progress in the chemoselective reduction and alkylation of carbonyl functions using this method.
Journal ArticleDOI
Lineare totalsynthese von (-)-acrl-toxin iii b
Journal ArticleDOI
Enantioselective Reduction of Ketones Induced by a C2‐Symmetrical Chiral Hydroxyamide/Titanium(IV) complex
TL;DR: The asymmetric reduction of ketones catalyzed by chiral titanium complex, prepared in situ from titanium tetraisopropoxide and a C 2-symmetrical chiral hydroxyamide, with catecholborane as the reducing agent afforded the corresponding chiral secondary alcohols in good yields with high enantioselectivity of up to>99% ee as discussed by the authors.
Journal ArticleDOI
Syntheses of spliceostatins and thailanstatins: a review.
TL;DR: A review of the synthetic strategies reported through the end of 2019 for spliceostatins/thailanstatins, a family of linear peptides/polyketides that inhibit pre-mRNA splicing, and as such act as potent cytotoxic compounds.
Journal ArticleDOI
Syntheses and antibacterial activities of 4 linear nonphenolic diarylheptanoids
Şemsi Betül Demir,Hatice Seçinti,Neslihan Çelebioğlu,Murat Ozdal,Alev Sezen,Özlem Gülmez,Ömer Faruk Algur,Hasan Seçen +7 more
TL;DR: Four linear nonphenolic diarylheptanoids were synthesized and their antibacterial activities were studied, exhibiting different degrees of antimicrobial activity at concentrations between 20–100 μg/disc against the test organisms.
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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.
Related Papers (5)
Reduction of Carbonyl Compounds with Chiral Oxazaborolidine Catalysts: A New Paradigm for Enantioselective Catalysis and a Powerful New Synthetic Method.
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