C-H and P-C(Ph) activation competitive processes caused by interaction with the solvate [cis-Pt(C6F5)2(thf)2].

Resumen

The study of the reaction between the ethylene [Pt(η2-H 2CCH2)(PPh3)2] or alkyne [Pt(η2-HC≡CR)(PPh3)2] (R = SiMe 3 1, But 2) complexes with [cis-Pt(C6F 5)2(thf)2] (thf = tetrahydrofuran) has enabled us to observe the existence of competitive processes between the activation of a P-C(Ph) bond on the PPh3 ligand, to give the binuclear derivative [cis-(C6F5)2Pt(-Ph)(-PPh2) Pt(PPh3)] 3, and the activation of a C-H bond of the unsaturated group, to give the corresponding (-hydride)(-vinyl) [cis,cis-(PPh 3)2Pt(-H)(-1κCα:η2- CHCH2)Pt(C6F5)2] 4 or (-hydride)(-alkynyl) [cis,cis-(PPh3)2Pt(-H)(- 1κCα:η2-C≡CR)Pt(C6F 5)2] (R = SiMe3 5, But 6) compounds, respectively. The monitoring of these reactions by NMR spectroscopy has allowed us to detect several intermediates, and to propose a mechanism for the C-H bond activation. In addition, the structures of the (-hydride)(-alkynyl) complex 5 and the unprecedented (-hydride)(-vinyl) derivative 4 have been obtained by X-ray crystallographic analyses. © The Royal Society of Chemistry.