Synthesis of a Novel Bisphosphonium Salt Based on 2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl (Binap)

The reaction between 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (Binap) and an equimolar amount of [Cu(OTf)2] (where OTf = trifluoromethylsulfonate) in acetonitrile afforded the new bisphosphonium salt 1 by a mechanism that must involve two C−H bond activations and the consequent intramolecular formation of two new C−P bonds. Compound 1 was characterized by spectroscopic and X-ray diffraction methods.