Highly stereoselective synthesis and application of functionalized tetravinylcyclotetrasiloxanes via catalytic reactions

An effective selective silylative coupling functionalization of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane with olefins catalyzed by ruthenium-hydride complex [RuHCl(CO)(PCy3)2] has been described. We have obtained numerous unsaturated derivatives of cyclosiloxane possessing a SiCHCHX fragments (where X = alkyl, aryl, silyl, alkoxy, amine and amide groups). One of the products synthesized (1,3,5,7-tetramethyl-1,3,5,7-tetra-(E)-4-bromostyrylcyclotetrasiloxane) has been efficiently coupled with aryl iodides in the presence of palladium(0) catalyst to yield substituted 4-bromostilbenes.

An effective silylative coupling functionalization of tetravinylcyclotetrasiloxane D4Vi with olefins (p-substituted styrenes, 1-hexene, butyl vinyl ether, tert-butyl vinyl ether, 1-vinyl-2-pyrrolidinone, 9-vinylcarbazole and vinyltrimethylsilane) catalyzed by ruthenium-hydride complex [RuHCl(CO)(PCy3)2] has been described. The resulting 1,3,5,7-tetramethyl-1,3,5,7-tetra-(E)-4-bromostyrylcyclotetrasiloxane has been efficiently coupled with aryl iodides in the presence of palladium(0) catalyst to yield substituted 4-bromostilbenes. Figure optionsDownload as PowerPoint slide