ALKYNYL/CHLORIDE EXCHANGE BETWEEN trans-PLATINUM(II) AND-PALLADIUM(II) CHLORIDES AND ALKYNYLSTANNANES. CRYSTAL STRUCTURE OF trans-

Article abstract of DOI:10.1016/0022-328X(86)80237-6

The reaction between alkynylstannanes (3,4) and trans-<(Et3P)2PtCl2> (1) gives trans-<(Et3P)2Pt(Cl)C<*>CR> (5) or trans-<(Et3P)2Pt(C<*>CR¹)2 (6) in high yield (R¹=H, Me, Ph).Complexes 5 react with alkynylstannanes to give the unsymmetrical bis(alkynyl) complexes 7, trans-<(Et3P)2Pt(C<*>CR²)C<*>CR¹> (R¹=Me, Ph; R²=H).Although the palladium(II) dichloride 2, trans-<(Bu3P)2PdCl2>, reacts much faster with alkynylstannanes than 1, the compounds trans-<(Bu3P)2PdC<*>CR¹)2> (9) are always obtained as mixtures with trans-<(Bu3P)2Pt(Cl)C<*>CR¹> (8), except for R¹=H.Compounds 8 can be obtained pure for R¹=Me or t-Bu if the reaction between 2 and 3 is carefully controlled.The dependence of the product distribution under experimental conditions in the case of the palladium(II) acetylides indicates that oxidative addition-reductive elimination reactions are involved.The crystal structure of trans-<(Et3P)2Pt(C<*>CMe)2> (6b) has been determined.All the products have been characterized by 13C, 31P and 195Pt NMR spectroscopy.