Rh(III)-Catalyzed Redox-Neutral Unsymmetrical C–H Alkylation and Amidation Reactions of N‑Phenoxyacetamides

A Rh­(III)-catalyzed unsymmetrical C–H alkylation and amidation of N-phenoxyacetamides with diazo compounds has been developed under mild and redox-neutral conditions, producing dinitrogen as the only byproduct. The reaction represents the first example of one-step, unsymmetrical difunctionalization of two ortho-C–H bonds. Experimental and computational studies support that N-phenoxyacetamides most likely undergo an initial ortho-C–H alkylation with diazo compounds via a Rh­(III)-catalyzed C–H activation, and the resulting Rh­(III) intermediate subsequently undergoes an intramolecular oxidative addition into the O–N bond to form a Rh­(V) nitrenoid species that is protonated and further directed toward electrophilic addition to the second ortho position of the phenyl ring. This work might provide a new direction for unsymmetrical C–H difunctionalization reactions in an efficient manner.