A general, catalytic, and enantioselective synthesis of α-amino acids
E. J. Corey* and John O. Link
*Department of Chemistry and Chemical Biology, Harvard
University, Cambridge, Massachusetts 02138, Email: coreychemistry.harvard.edu
E. J. Corey, J. O. Link, J. Am. Chem. Soc., 1992, 114, 1906-1908.
DOI: 10.1021/ja00031a069
Abstract
A novel enantioselective synthesis of α-amino acids has been developed, which is broad in scope, simple in application, and advantageous for many α-amino acids of interest in chemistry, biology, medicine.
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Details
E. J. Corey and John O. Link from Harvard University report a new, practical, and general approach to synthesizing α-amino acids using a catalytic enantioselective reduction of ketones. This method leverages a chiral catalyst, (S)-oxazaborolidine, to reduce trichloromethyl ketones to (R) secondary alcohols with high enantioselectivity. The resulting (R)-(trichloromethyl)carbinols are then converted to (S)-α-azido acids via a gem-dichlorooxirane intermediate, followed by reduction to (S)-α-amino acids. The process is efficient, yielding high enantiomeric excesses and demonstrating broad applicability across various α-amino acids, including those with bulky substituents like tert-butylglycine. The method is advantageous for its simplicity, mild reaction conditions, and high yields, making it suitable for synthesizing both natural and unnatural α-amino acids, which are valuable in chemistry, biology, and medicine. The research was supported by grants from the National Institutes of Health and the National Science Foundation.
Key Words
Corey-Bakshi-Shibata Reduction, Jocic Reaction, Azides, Reduction of Azides, α-Amino Acids, Catecholborane, Hydrogen
ID: J48-Y1992-190