Zinc Triflate Catalyzed C-Benzylation: Chemo- and Regioselective Route to Amido Substituted Diaryl and Arylheteroarylmethanes

An unprecedented zinc triflate catalyzed selective C-benzylation of anilides and heteroaryl amides with benzyl chlorides having electron-donating group at para-position is reported. The protocol offers moderate to high yield of para-amido substituted diaryl and arylheteroarylmethanes, uses cheap and easily available benzyl chlorides as the benzylating agent, catalytic amount of zinc triflate, and takes place under ambient conditions. Aminodiarylmethane derivatives can be obtained by hydrolysis of the corresponding amides. The methodology has also been applied for preparing dimethoxydiarylmethanes in good yields, which are the key precursors for synthesis of phenolic natural products.