An Efficient Copper-catalyzed Nucleophilic Addition to N-Acyliminium Ions Derived from N-Benzyloxycarbonylamino Sulfones: A Novel Approach to C-3 Functionalization of 2-Phenylimidazo[1,2-a]pyridine

摘要

A general and efficient method for C-3 functionalization of 2-phenylimidazo[1,2-a]pyridine has been developed. The reaction employs Cu(OTf)(2) as a catalyst at 10 mol% loading, proceeds in dimethyl sulfoxide solvent, and utilizes bench-stable solid N-benzyloxycarbonylamino sulfones derived from aromatic and aliphatic aldehydes as N-acyliminium ion precursors. The imidazo[1,2-a]pyridine products are obtained in moderate to good yields.