Trimethylsilylplatinum(IV) complexes as reaction intermediates

Abstract

The oxidative addition of I 2, PhCH 2Br and MeI with [Pt(CH 2SiMe 3) 2(DPK)], 1, DPK = di-2-pyridyl ketone, occurred with trans stereochemistry to give [PtI 2(CH 2SiMe 3) 2(DPK)], [PtBr(CH 2Ph)(CH 2SiMe 3) 2(DPK)] and [PtIMe(CH 2SiMe 3) 2(DPK)], respectively. Complex 1 reacted with acids HX (X = Cl or CF 3CO 2) to give initially the hydridoplatinum complexes [PtHX(CH 2SiMe 3) 2(DPK)], but these complexes were thermally unstable and decomposed largely by α-silyl migration to give compounds such as [PtX(SiMe 3)Me 2(DPK)], as determined by monitoring the reactions by NMR at low temperature. With excess acid, HX, at room temperature, the products were largely [PtX 2(DPK)], CH 4 and Me 3SiX with Me 4Si as a minor product only. The mechanism of the easy Si–CH 2 bond cleavage is discussed.