Preparation of Axially ChiralN,N′-Diarylimidazolium andN-Arylthiazolium Salts and Evaluation of Their Catalytic Potential in the Benzoin and in the Intramolecular Stetter Reactions
作者:Jens Pesch、Klaus Harms、Thorsten Bach
DOI:10.1002/ejoc.200300762
日期:2004.5
imidazolium salts 15b, the thiazolium salts proved to be suitable catalysts in the benzoin condensation of benzaldehyde (1 2) and in the intramolecular Stetter reaction of the α,β-unsaturated ester 9a. The best results obtained with catalyst 19 (20 mol %) were 85% yield of product 2 (40% ee) and 75% yield of product 10a (50% ee). The stereogenic axis of catalyst 19 is not configurationallystable in the