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

摘要

Protonolysis of the (trimethylsilyl)methyl-platinum bonds in [Pt(CH_2SiMe_3)_2(NN)] (NN = 4,4'-di-tert-butyl-2,2'-bipyridine) and in [Pt(CH_2SiMe_3)(NNC)] (NNC = C_6H_4-2-CH=N-trans-C_6H_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 alpha-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.