Facile conversion of bis(alkynyl) into diyne ligand on platinum assisted by electrophilic gold phosphine

Abstract 31 P NMR spectroscopy measurements were used to establish the course for the stoichiometric-dependent reactions between [Au(PPh 3 )] + and [Pt(CCPh) 2 (dppf)] ( 1 ), which for equimolar amounts afford as the unique product [Pt-{η 3 -C(CCPh)C(Ph)Au(PPh 3 )}(dppf)] + ( 2 ), but any excess of 1 gives also [Pt(η 2 -PhCCCCPh)(dppf)] ( 3 ) [dppf=1,1′-bis(diphenylphosphine)ferrocene]. Both compounds 2 and 3 were obtained straightforwardly by the reactions of 3 with [Au(PPh 3 )] + and [Pt(C 2 H 4 )(dppf)] with 1,4-diphenylbutadiyne, respectively. The X-ray crystal structure analysis of 3 confirmed a trigonal-planar coordination geometry about the platinum atom, and a bent η 2 -coordinated diyne ligand.