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An Efficient Nucleophilic Carbene Catalyst for the Asymmetric Benzoin Condensation
Author(s) -
Enders Dieter,
Kallfass Ulrike
Publication year - 2002
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/1521-3773(20020517)41:10<1743::aid-anie1743>3.0.co;2-q
Subject(s) - nucleophile , carbene , steric effects , chemistry , bicyclic molecule , benzoin , catalysis , enantiomer , medicinal chemistry , enantioselective synthesis , organic chemistry
The chiral bicyclic triazolium salt 1 is currently the most efficient precatalyst for the asymmetric benzoin condensation. The substituted acyloins 3 are obtained in moderate to good yields and with very good enantiomeric excesses from the corresponding aldehydes 2 . The high asymmetric induction is presumably based on the conformational rigidity of the bicyclic nucleophilic carbene catalyst and on the steric hindrance of the tert ‐butyl group in the Breslow intermediate.