Gold complexes of bis-indazole-derived N-Heterocyclic carbene: Synthesis, structural characterizations, and catalysis

• The synthesis of Indy-NHC ligands were improved by Ti reagents, with high yield and mild reaction conditions. • A novel series of bis Indy-NHC gold complexes were successfully synthesized. • All Indy-NHC gold complexes showed catalytic activity toward the oxidation of diphenylmethane. • It is bis i Pr-Indy complex E1 that catalyze the oxidation of various benzylic substrates with an excellent yield. A novel series of bis Indy-NHC gold complexes have been developed and investigated via a mild Ag-carbene transfer route. The obtained complexes were characterized by NMR spectroscopy and X-ray diffraction analysis. The catalytic property of these gold complexes was further evaluated in the oxidation of benzylic. The gold complex E1 showed a high catalytic activity in the oxidation of various benzylic substrates, resulting in the corresponding carbonyl compounds with excellent yields using TBHP as oxidant.