The enantioselective three-component Michael addition-Pictet-Spengler sequence of beta-ketoesters 1, alpha,beta-unsaturated aldehydes 2 and tryptamines 4 represents a facile and rapid one-pot access to highly substituted indoloquinolizidines in moderate to excellent yields and good to excellent enantioselectivities.
A facile and green method catalyzed by α-amylase has been developed for the synthesis of highly substituted indoloquinolizines using tryptamines, β-ketoesters and α,β-unsaturated aldehydes. The reaction afforded a variety of products in moderate to good yields and with high diastereoselectivity. The densely functionalized products were obtained in a single synthetic operation under mild conditions