Manganese (iii) catalyzed c—h aminations

Abstract

Reactions that directly install nitrogen into C—H bonds of complex molecules are significant because of their potential to change the chemical and biological properties of a given compound. Selective intramolecular C—H amination reactions that achieve high levels of reactivity, while maintaining excellent site-selectivity and functional-group tolerance is a challenging problem. Herein is reported a manganese perchlorophthalocyanine catalyst [Mn(ClPc)] for intermolecular benzylic C—H amination of bioactive molecules and natural products that proceeds with unprecedented levels of reactivity and site-selectivity. In the presence of Brønsted or Lewis acid, the [Mn(ClPc)]-catalyzed C—H amination demonstrates unique tolerance for tertiary amine, pyridine and benzimidazole functionalities. Mechanistic studies indicate that C—H amination proceeds through an electrophilic metallonitrene intermediate via a stepwise pathway where C—H cleavage is the rate-determining step of the reaction. Collectively these mechanistic features contrast previous base-metal catalyzed C—H aminations. The catalyst can be a compound of Formula I: