Chiral diphenylperhydroindolinol silyl ether catalyzed domino oxa-Michael–aldol condensations for the asymmetric synthesis of benzopyrans
摘要:
Asymmetric domino oxa-Michael-aldol reactions between trans-cinnamaldehydes and salicylic aldehyde derivatives have been developed. Using (2S,3aS,7aS)-diphenylperhydro indolinol silyl ether 4i as the catalyst, most corresponding chiral benzopyrans can be obtained with excellent chemo- and enantioselectivities. (C) 2014 Elsevier Ltd. All rights reserved.