Reactivity of platinum alkyne complexes towards N-fluorobenzenesulfonimide: formation of platinum compounds bearing a β-fluorovinyl ligand

Abstract

The platinum(0) alkyne complexes [Pt(L)(η²-PhCCPh)] 1–4 were synthesized by reactions of [Pt(cod)₂] with diphenylacetylene and a phosphine ligand precursor (1: L = dcpe, 2: L = xantphos, 3: L = κ²-(P,N)-iPr₂PC₃H₆NMe₂, 4: L = κ²-(P,N)-iPr₂PC₂H₄NMe₂). Treatment of 1 or 4 with NFSI gave the complexes [Pt(F){N(SO₂Ph)₂}(dcpe)] (5) and [Pt(PhCCFPh){N(SO₂Ph)₂}{κ²-(P,N)-iPr₂PC₂H₄NMe₂}] (8), whereas the reactivity of 2 and 3 towards NFSI led to product mixtures. The compounds [Pt(F){N(SO₂Ph)₂}(xantphos)] (6a) as well as [Pt(PhCCFPh){N(SO₂Ph)₂}{κ²-(P,N)-iPr₂PC₂H₄NMe₂}] (7a) and [Pt(PhCCFPh)(F){κ²-(P,N)-iPr₂PC₂H₄NMe₂}] (7b) were clearly identified. Ligand exchange reactions at 8 resulted in the formation of the β-fluorovinyl platinum(II) complexes [Pt(PhCCFPh){OC(O)CF₃}{κ²-(P,N)-iPr₂PC₂H₄NMe₂}] (9), [Pt(PhCCFPh)(FHF){κ²-(P,N)-iPr₂PC₂H₄NMe₂}] (10) and [Pt(PhCCFPh)(F){κ²-(P,N)-iPr₂PC₂H₄NMe₂}] (11). Treatment of 8 with dihydrogen yielded the fluorinated olefin (Z)-(1-fluoroethene-1,2-diyl)dibenzene and [Pt{N(SO₂Ph)₂}(H){κ²-(P,N)-iPr₂PC₂H₄NMe₂}] (12).