Highly Enantioselective Benzoin Condensation Reactions Involving a Bifunctional Protic Pentafluorophenyl-Substituted Triazolium Precatalyst
Louise Baragwanath, Christopher A. Rose, Kirsten Zeitler and Stephen J. Connon*
*Centre for Synthesis and Chemical Biology, School of
Chemistry, University of Dublin, Trinity College, Dublin 2, Ireland, Email:
connonstcd.ie
L. Baragwanath, C. A. Rose, K. Zeitler, S. J. Connon, J. Org. Chem., 2009, 74, 9214-9217.
DOI: 10.1021/jo902018j
Abstract
A hydrogen bond donating substituent to improve enantiocontrol together with an acidifying pentafluorophenyl substituent to enhance catalyst efficiency results in a triazolium ion precatalyst that promotes the asymmetric benzoin condensation with excellent efficiency and unprecedented enantioselectivity.
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Key Words
acyloins, asymmetric catalysis, benzoin condensation, carbenes, triazolium salts, organocatalysis
ID: J42-Y2009-3520