TRIS(TRIMETHYLSILYL)SILANE AS A RADICAL-BASED REDUCING AGENT IN SYNTHESIS

Tris(trimethylsilyl)silane is an effective reducing agent for organic halides, selenides, xanthates, and isocyanides, as well as an effective hydrosilylating agent for dialkyl ketones and alkenes. The silane functions as a mediator in the formation of intermolecular carbon-carbon bonds via radicals and allows a variety of organic substrates to be used as alkyl radical percursors. Absolute rate constants for the reaction of (Me3Si)3Si radicals with a variety of organic compounds have been measured in solution by laser flash photolysis. At 294 K rate constants are > 5 x 10(7) M-1 s-1 for C = C double bonds that are activated by neighboring pi-electron systems or by electron-withdrawing groups. For other substrates, reactivities decreased in the order xanthate > selenide > isocyanide > nitro > sulfide.