Nitroxide chemistry. Part IX. Reaction of NN-bistrifluoromethyl-amino-oxyl with tetramethylsilane, chloromethylsilanes, and methoxymethylsilanes

Abstract

Reaction of the oxyl (CF₃)₂N·O· with the silanes Me_nSiCl_4–n(n= 1–4) involves formation of silyl esters R₃Si·CO₂·N(CF₃)₂via the disubstitution compounds R₃Si·CH[O·N(CF₃)₂]₂. Under the conditions employed the silyl esters are unstable and decompose either by a radical mechanism to give carbon dioxide and bistrifluoromethyl-amino and silyl (R₃Si·; R₃= Me₃ or Me₂Cl) radicals or by an intramolecular elimination of carbon monoxide to afford the hydroxylamine R₃Si·O·N(CF₃)₂(R₃= MeCl₂ or Cl₃) which competes with the radical mechanism. The silanes (MeO)_nSiMe_4–n(n= 3 and 4) react to give the substitution products (CF₃)₂N·O·CH₂·O·SiMe(OMe)₂ and (CF₃)₂N·O·CH₂·O·Si(OMe)₃, respectively. Further oxyl attack on the latter product gives exclusively the silane [(CF₃)₂N·O·CH₂·O]₂Si(OMe)₂.