[Pd(IPr*OMe)(acac)Cl]: Tuning the N-Heterocyclic Carbene in Catalytic C–N Bond Formation

A new N-heterocyclic ligand IPr* OMe [ N, N ′-bis(2,6-bis(diphenylmethyl)-4-methoxyphenyl)imidazol-2-ylidene] has been synthesized and compared with its earlier methyl-substituted congener IPr* [ N, N ′-bis(2,6-bis(diphenylmethyl)-4-methylphenyl)imidazol-2-ylidene]. IPr* OMe was successfully bound to palladium, and the catalytic activity of the resulting complex [Pd(IPr* OMe )(acac)Cl] was investigated in Buchwald–Hartwig arylamination. Catalytic activity was compared to that of [Pd(IPr*)(acac)Cl].