Gold-catalyzed naphthalene functionalization

Abstract

The complexes IPrMCl (IPr = 1,3-bis(diisopropylphenyl)imidazol-2-ylidene, M = Cu, 1a; M = Au, 1b) in the presence of one equiv of NaBAr’4 (Ar’ = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) catalyze the transfer of carbene groups :C(R)CO2Et (R = H, Me) from N2C(R)CO2Et affording products depending of the nature of the metal center. The copper-based catalyst exclusively provides a cycloheptatriene derivative from the Büchner reaction whereas the gold analog gives a mixture of products derived either from the formal insertion of the carbene unit into the aromatic C-H bond or from its addition to a double bond. In addition, no byproducts derived from carbene coupling are observed