Trimethylsilylplatinum(IV) complexes as reaction intermediates

The oxidative addition of I2, PhCH2Br and MeI with [Pt(CH2SiMe3)2(DPK)], 1, DPK = di-2-pyridyl ketone, occurred with trans stereochemistry to give [PtI2(CH2SiMe3)2(DPK)], [PtBr(CH2Ph)(CH2SiMe3)2(DPK)] and [PtIMe(CH2SiMe3)2(DPK)], respectively. Complex 1 reacted with acids HX (X = Cl or CF3CO2) to give initially the hydridoplatinum complexes [PtHX(CH2SiMe3)2(DPK)], but these complexes were thermally unstable and decomposed largely by α-silyl migration to give compounds such as [PtX(SiMe3)Me2(DPK)], as determined by monitoring the reactions by NMR at low temperature. With excess acid, HX, at room temperature, the products were largely [PtX2(DPK)], CH4 and Me3SiX with Me4Si as a minor product only. The mechanism of the easy Si–CH2 bond cleavage is discussed.

Easy Si–C bond cleavage occurs in complexes such as [PtH(CH2SiMe3)2(DPK)]+ by a mechanism involving α-silyl migration to platinum.Figure optionsDownload as PowerPoint slideResearch highlights
► Silicon–carbon and carbon–hydrogen bond activation.
► Platinum-silyl intermediates.
► α-Silyl migration to platinum is easy.