Ruthenium-Catalyzed Ionic Hydrogenation of Aziridinium Cations

Abstract

Hydride transfer from CpRu(dppm)H (dppm = bis(diphenylphosphino)methane) to asymmetrically substituted aziridinium cations occurs at the less substituted carbon when the substituents are alkyl, but at the more substituted carbon when the substituent is phenyl. Some of the phenyl-substituted aziridinium cations react with the amine resulting from H- transfer; the reaction of the same phenyl-substituted cation with Cp*Ru(dppf)H (dppf = 1,1‘-bis(diphenylphosphino)ferrocene) shows evidence of electron transfer. CpRu(dppm)H can catalyze the hydrogenation of the same aziridinium cations to ammonium cations; this reaction occurs with the same regioselectivity as the stoichiometric H- transfer reactions.