Iridafurans by Coupling of Alkynes and Aldehydes on a TpMe2Ir System. Facile Demethoxycarbonylation of a β-CO2Me Substituent

Abstract

The reaction of TpMe2Ir(C2H4)2 (TpMe2 = hydrotris(3,5-dimethylpyrazolyl)borate) with 1 equiv of DMAD (DMAD = dimethyl acetylenedicarboxylate) and 1 equiv of an aromatic aldehyde cleanly yields iridafuran derivatives, characterized by spectroscopy and X-ray analysis. These derivatives experience a stepwise selective hydrolysis−decarboxylation of the CO2Me group located at the β-carbon of the metallacycle, which proceeds through two isolable intermediates: a water adduct of an iridaenolate and an iridium carboxylate bicyclic species.