A stable gold(i)–enyne species obtained by alkyne carboauration in a complex rearrangement

Abstract

An unprecedented tetranuclear gold derivative with unusual gold-enyne moieties is prepared by a mild and neat rearrangement of a dinuclear gold complex with a bridging bis(diphenylphosphino)alkyne and terminal alkynyl ligands. The complex originates as a consequence of an intramolecular addition of the AuCCTol fragment to the internal diphosphine triple bond Ph₂PCCPPh₂. The crystal structure of the tetranuclear complex shows a dinuclear metallacycle with a very short Au⋯Au bond interaction and bridging phosphino–enyne ligands. This disposition clearly stabilises the elusive vinyl gold species omnipresent as intermediates in gold-catalysed reactions.