Studies Toward Copper-Catalyzed Asymmetric Nitroaldol and Iron-Catalyzed Thia-Michael/Aldol Cascade Reactions

Abstract

The thesis contains four chapters. Chapter I describes a brief literature survey on asymmetric metal catalysis utilizing chiral tetradentate salen, salan, salelan ligands and tridentate ?-aminoalcohol derived ligands. Chapter II focuses on the sythesis of chiral Cu(II)-complexes bearing salen, salan, salalen and salalan ligands and their application towards enantioselective nitroaldol reaction. The reaction is mild and afforded aryl, heteroaryl, naphthyl and alkyl ?-nitroalcohols in high enantioselectivities at room temperature without any additivies. Chapter III presents the synthesis of chiral tetradentate salen ligand and tridentate ?-aminoalcohol derived ligands for Fe-catalyzed enantioselective thia-Michael-aldol cascade reaction. The reaction proceeded readily between aryl, heteroaryl, alkyl chalcones and 1,4-dithiane-2,5-diol in the presence of Fe-catalyst to afford the corresponding trisubstituted tetrahydrothiophenes in good enantioselectivities.