Catalyst-free synthesis of trisubstituted tetrahydrothiophenes in water via a cascade sulfa-Michael/aldol (Henry) type reaction†
Abstract
A simple, efficient, eco-friendly and catalyst-free procedure was developed for the construction of trisubstituted tetrahydrothiophenes via sulfa-Michael/aldol (Henry) cascade reaction in water. The protocol, simply utilizing readily-available starting materials under clean reaction conditions, provided an alternative and highly attractive approach to a series of tetrahydrothiophene derivatives from a wide range of substrates in good yields (up to 93%) with excellent diastereoselectivities (up to >99 : 1).