C(sp2)-C(sp2) Reductive Elimination from Well-Defined Diarylgold(lll) Complexes

A series of well-defined phosphine-ligated diarylgold(III) complexes cis-[Au(L)(Ar-F)(Ar')(Cl)] were prepared, and detailed kinetics of the C(sp(2))-C(sp(2)) reductive elimination from these complexes were studied. The mechanism of the reductive elimination from the complexes cis-[Au(L)(Ar (F))(Ar')(Cl)] was further studied by theoretical calculations. The combination of experimental and theoretical results suggests that the biaryl reductive elimination from organogold(IIl) complexes as-[Au(L)(Ar (F))(Ar')(Cl)] proceeds through a concerted biaryl-forming pathway from the four-coordinated Au(IIl) metal center. These studies also disclose that the steric hindrance of the phosphine ligands plays a major role in promoting the biaiyl-forming reductive elimination from diarylgold(III) complexes a's-[Au(L)(Ar (F))(Ar')(Cl)], while electronic properties of these ligands have a much smaller effect. Futhermore, it was found that the complexes with more weakly electron withdrawing aryl ligands undergo reductive elimination more quickly and the elimination rate is not sensitive to the polarity of the solvents.