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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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Journal ArticleDOI
The oxazaborolidine-borane reduction of ketones: Identification and reactivity of transient intermediates
TL;DR: In this paper, the reaction pathway for oxazaborolidine-based borane reduction of ketones has revealed a transient intermediate which can competitively reduce ketones, and this intermediate can be used to obtain a more stable intermediate.
Journal ArticleDOI
The Diaryl(oxy)methyl Group: More than an Innocent Bystander in Chiral Auxiliaries, Catalysts, and Dopants
TL;DR: This Minireview highlights developments in stereochemistry when the diaryl(oxy)methyl group is involved, with emphasis given to the beneficial effect of this moiety.
Journal ArticleDOI
Efficient ring opening of epoxides with trimethylsilyl azide and cyanide catalyzed by erbium(III) triflate
Antonio Domenico Procopio,Paola Costanzo,Renato Dalpozzo,Loredana Maiuolo,Monica Nardi,Manuela Oliverio +5 more
TL;DR: In this paper, a ring-opened compound can be opened under neutral conditions with TMSN3 and TMSCN in the presence of catalytic amounts of Lewis acid, affording the corresponding ring opened compounds in high yields.
Journal ArticleDOI
Catalytic asymmetric synthesis of secondary alcohols using chiral cis-1-amino-2-hydroxy-1,2,3,4-tetrahydronaphthalene as chiral ligand
Cristina M Bellucci,Antonio Bergamini,Pier Giorgio Cozzi,Angelo Papa,Emilio Tagliavini,Achille Umani-Ronchi +5 more
TL;DR: In this article, the synthesis and resolution of cis-1-amino-2-hydroxy-1,2,3,4-tetrahydronaphthalene5 by a simple and straightforward methodology has been achieved.
Journal ArticleDOI
Highly Stereocontrolled Synthesis of trans-2,6-Disubstituted-5-methyl-3,6-dihydropyrans: Stereoselective Synthesis of the Bicyclic Core of Penostatin B
TL;DR: The versatility of the above method was also demonstrated for the construction of the bicyclic core present in penostatin B in a concise and highly stereoselective manner.
References
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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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