H2O-Regulated Chemoselectivity in Oxa- Versus Aza-Michael Reactions.

A H2O-regulated chemoselective addition in oxa- and aza-Michael reactions for aminoalcohols and mixtures of structurally similar alcohols and amines was reported. The oxa-Michael reactions might be kinetically controlled, and the reactions to produce O-selective products were slowed by the addition of water. The electrophilicity of Michael acceptors and the steric hindrance of Michael donors also affect the ratios of O/N products. This method offers novel ideas over conventional metal-catalyzed or ligand-induced strategies.