Selective Formation of α-Cleavage Cycloadduct of Oxirane with Heterocumulene Promoted by High-Coordinated Trialkyltin Complexes

Abstract

Abstract In the reaction of monosubstituted oxiranes and heterocumulenes, trialkyltin iodides coordinated by phosphine oxides effectively catalyzed the formation of heterocycles via cleavage at the substituted site in the oxirane ring, while other types of organotin complexes or noncomplexed organotin iodides promoted selective cleavage at the opposite site. A mechanistic investigation demonstrated that the coordination of phosphine oxide promotes the reverse reaction of the oxirane-ring cleavage leading to the predominant formation of α-cleavage cycloadducts.