Imino ene-type reaction of enamines with N-sulfonylimines and application to diastereoselective synthesis of N-sulfonyl-1,3-diamines

Abstract

Enamines react rapidly with N-sulfonylimines to afford imino ene-type adducts. The reaction proceeds even at −78°C in the presence of acetic acid and shows high diastereoselectivity. Acid hydrolysis of imino ene-type products affords β-amino ketones, and reduction with NaBH3CN furnishes N-sulfonyl-1,3-diamines with high diastereoselectivities. The stereochemistry of these transformations is considered based on transition state models.