Copper-Catalyzed Hiyama Coupling of (Hetero)aryltriethoxysilanes with (Hetero)aryl Iodides

A Cu-catalyzed Hiyama coupling was achieved, which proceeds in the absence of an ancillary ligand for aryl-heteroaryl and heteroaryl-heteroaryl couplings. A P,N-ligand is required to obtain the best product yields for aryl-aryl couplings. In addition to facilitating transmetalation, CsF is also found to function as a stabilizer of the [CuAr] species, potentially generated as an intermediate after transmetalation of aryltriethoxysilanes with Cu-catalysts in the absence of ancillary ligands.