Polymethylhydrosiloxane (PMHS) reacts with aliphatic and aromatic alcohols at room temperature in the presence of [CuH(PPh 3 )] 6 complex catalyst to give poly[(methyl) (alkoxy)siloxane]s in high yields. Reactivity of alcohols decreases in the order of p-methoxyphenol > p-cresol > phenol > benzyl alcohol > allyl alcohol > ethanol > isopropanol > tert-butyl alcohol. Partially p-cresylated polymers, which still retain unreacted SiAH bonds, react further with ethylene glycol or water to form cross-linked polymers, which, depending on the extent of cross linking, gelate during the cross-linking process. Propargyl alcohol reacts with PMHS very rapidly to give exhaustively and partially propargyloxylated PMHS. Resulting polymers, upon heating, undergo crosslinking. Partially propargyloxylated polymers display high thermal stability [T d5 (temperature of 5% weight loss) > 500 C] as compared with starting PMHS (243 C) and exhaustively propargyloxylated one (414 C).Additional Supporting Information can be viewed in the online issue of this article.

The anionic oligomerization of ethylphenylketene (EPK) by lithium benzyl alkoxide on a polystyrene resin readily afforded the corresponding lithium enolate immobilized on beads through a benzyl ester linker. The lithium enolate so prepared was applied as a solid‐supported initiator for the anionic synthesis of poly(methyl methacrylate), which was readily isolated from the resin by selective cleavage of the benzyl ester linker.