Regioselective Hydromethoxycarbonylation of Terminal Alkynes Catalyzed by Palladium(II)–Tetraphos Complexes

An in situ generated dinuclear palladium hydride complex bearing cis,trans,cis-1,2,3,4-tetrakis­(diphenylphosphanyl)­cyclobutane catalyzed the hydromethoxycarbonylation of terminal alkynes, giving the corresponding branched α,β-unsaturated ester (A) with high regioselectivity.