Thia-Michael Reaction under Heterogeneous Catalysis

Thia-Michael reactions between aliphatic and aromatic thiols various Michael acceptors were performed under environmentally-friendly solvent-free conditions using Amberlyst® A21 as a recyclable heterogeneous catalyst to efficiently obtain the corresponding adducts in high yields. Ethyl acrylate was main acceptor used, although others such acrylamide, linear, cyclic enones also utilized successfully. Bifunctional donor, 3-mercaptopropanoic acid, positively furnished product, albeit lower yield after leaving reaction take place for longer time. The easy safe handle successfully recycled five consecutive cycles.