Quaternary Ammonium Salts as Alkylating Reagents in C-H Activation Chemistry.

A rhodium(I)-catalyzed alkylation reaction of benzylic amines via C(sp)-H activation using quaternary ammonium salts as alkyl source is described. The reaction proceeds via in situ formation of an olefin via Hofmann elimination, which is the actual alkylating reagent. This represents an operationally simple method for substituting gaseous and liquid olefins with solid quaternary ammonium salts as alkylating reagents, which is transferable to other C-H activation protocols as well.