[Pd(IPr*(acac)Cl]: An Easily Synthesized, Bulky Precatalyst for C-N Bond Formation

A very straightforward synthesis of [Pd(IPr*)(acac)Cl] has been developed from commercially available Pd(acac)(2) and the easily prepared IPr*center dot HCl (acac = acetylacetonate; IPr* = N,N'-bis(2,6-bis(diphenylmethyl)-4-methylphenyl)imidazol-2-ylidene). The reactivity of the resulting complex [Pd(IPr*)(acac)Cl] (1) as a highly active Pd-II precatalyst for the Buchwald-Hartwig arylamination coupling has been explored. A wide range of substrates with varying electronic and steric demands of both coupling partners has been screened successfully. The chemoselectivity of the reaction was also explored by using aryl heterodihalides.