Silicone compound useful as polymerization initiator for living radical polymerization

Abstract

The present invention relates to silsesquioxane derivs. I, which are good living radical polymn. initiators, wherein R1 = independently H, alkyl, (un)substituted aryl, or (un)substituted arylalkyl; A1 = halogenated sulfonyl group-substituted org. group, preferably II; X = halogen; R2 = alkyl; a = 0-2 integer; and Z1 = a single bond or C1-10 alkylene. The silsesquioxanes initiate acrylic monomers and an acrylic polymer are formed from one site of the silsesquioxane structure. Since the halogenated sulfonyl group has strong electrophilicity, various silsesquioxane derivs. can be synthesized by reacting the silicon compd. with various nucleophilic reagents. The silicone compd. can hence be used as an intermediate useful in org. syntheses. Thus, 211.5 g phenyltrichlorosilane was hydrolyzed to give a silsesquioxane with wt. av. mol. wt. 3100, sodium hydroxide was added therein and reacted to give a sodium phenylsilsesquioxane, 10 g of which was reacted with 10.17 g 2-(4-chlorosulfonyl)ethyltrichlorosilane methylene chloride soln. to give a sulfonyl chloride-substituted phenylsilsesquioxane, which was used for the polymn. of Me methacrylate in the presence of L-sparteine and cuprous bromide, giving polymethyl methacrylate with conversion 6.51 mol%, Mn 3000, and polydispersity 1.11. [on SciFinder (R)]