Reactivity of carboxylate complexes of platinum(II) towards carbon monoxide, sulphur dioxide, and some olefins and acetylenes

Abstract

Reactions of the carboxylate complexes Pt(OCOCH₃)₂(PPh₃)₂ and Pt(OCOCF₃)₂(PPh₃)₂ with carbon monoxide and certain olefins and acetyienes in alcoholic media support a mechanism which involves the formation of an intermediate alkoxide complex, Pt(OCOCY₃)(OR)(PPh₃)₂(Y = H or F; R = Me or Et). The alkoxide reacts with carbon monoxide to give alkoxycarbonyl complexes, Pt(OCOCY₃)(COOR)(PPh₃)₂ but in the presence of diphenylacetylene a hydride shift occurs to give a platinum hydride species which results in the formation of an alkenyl complex, Pt(OCOCF₃)(PhCCHPh)(PPh₃)₂ when Y = F and Pt(PhCCPh)(PPh₃)₂ when Y = H. Reactions with hexafluorobut-2-yne, tetrafluoroethylene, tetrachloroethylene, and tetracyanoethylene are also described. Sulphur dioxide reacts with Pt(OCOCH₃)₂(PPh₃)₂ in methanol to give the methylsulphonate complex, Pt(SO₂OMe)₂(PPh₃)₂.