Organocatalytic highly enantioselective tandem Michael–Knoevenagel reaction for the synthesis of substituted thiochromanes
作者:Rajasekhar Dodda、Tanmay Mandal、Cong-Gui Zhao
DOI:10.1016/j.tetlet.2008.01.113
日期:2008.3
Enantioenriched tetrasubstituted thiochromanes have been synthesized using a tandem Michael addition-Knoevenagel reaction between 2-mercaptobenzaldehydes and benzylidenemalonates with a 9-epi-aminoquinine thiourea derivative as the catalyst. Steric and electron effects were found to affect profoundly the enantioselectivity and diastereoselectivity of the reaction.