Activation of Si−C or C−H Bonds in Tetramethylsilane:  Evidence from Protonolysis of (Trimethylsilyl)methyl−Platinum Bonds

Abstract

Protonolysis of the (trimethylsilyl)methyl−platinum bonds in [Pt(CH 2 SiMe 3 ) 2 (NN)] (NN = 4,4‘-di- tert -butyl-2,2‘-bipyridine) and in [Pt(CH 2 SiMe 3 )(NNC)] (NNC = C 6 H 4 -2-CH N- trans -C 6 H 10 -2-N CHPh) is suggested to occur by protonation at platinum to give a 16-electron hydridoplatinum(IV) intermediate, followed by either rapid, concerted rearrangement to give a methyl(trimethylsilyl)platinum(IV) complex intermediate or reductive coupling to form tetramethylsilane (TMS). The direct characterization of (trimethylsilyl)platinum(IV) complex intermediates, such as [PtBrMe 2 (SiMe 3 )(NN)], proves that the α-migration of the trimethylsilyl group from carbon to a cationic platinum center is easy and suggests that Si−C bond activation by electrophilic platinum(II) complexes may be an alternative to C−H activation.