HALOMETHYL-METAL COMPOUNDS .29. REACTIONS OF MONOHALOMETHYL-MERCURY COMPOUNDS WITH ORGANOSILICON HYDRIDES - A NEW PREPARATION OF METHYLSILICON COMPOUNDS

The reactions of the halomethyl-mercury reagents Hg(CH2Br)2, ICH2HgI/ Ph2Hg and Hg(CH2Br)2/Ph2Hg with a number of organosilicon hydrides [Et3SiH, Ph3SiH, Ph2SiH2, ViPh2SiH, Me2PhSiH, Me2(ZC6H4)SiH (Z = p-Cl, p-F, m-CF3 and p-CH3)] resulted in CH2 insertion into the SiH bonds to give methylsilanes. A similar reaction with triethylgermane gave triethylmethylgermane. Although the mechanism of this new methylenation reaction is not known, a free methylene process seems to be excluded and it is likely that a direct reaction between the halomethyl- mercury reagent and the hydride is involved. A Hammett study of the reaction of Hg(CH2Br)2 with substituted phenyldimethylsilanes showed a good correlation between log krel and σ°, giving a ρ{variant} value of -1.31 ± 0.04. A competition study established that triethylsilane is ca. 12 times more reactive toward bis(bromomethyl)mercury than is 3-ethyl-2-pentene. © 1969.