Dehydrogenative silylation of vinylarenes with Et3SiH catalyzed by mixed valent CCC-NHC Rh(III)/Rh(I) pincer complex

Le résumé fourni par la source

Selective dehydrogenative silylation of vinylarenes with tertiary silanes catalyzed by well-defined CCC–NHC pincer Rh complexes has been developed. The CCC–NHC pincer Rh precatalysts [( Bu C i C i C Bu )RhCl(µ-Cl) 2 Rh(COD)] ( 7 ), [( Bu C i C i C Bu )RhCl(µ-Cl)] 2 ( 8 ), [( Bu C i C i C Bu )RhCl 2 (NHMe 2 )] ( 9 ), and [( Bu C i C i C Bu )RhCl 2 Py] ( 10 ), ( Bu C i C i C Bu = 2-((1,3-bis(N-butylimidazol-2-ylidene)phenylene) that were evaluated were all found to promote the dehydrogenative silylation of vinylarenes with Et 3 SiH to selectively form the corresponding ( E )-alkenylsilane under solvent-free conditions. The most active precatalyst was the novel mixed valent Rh(III)/Rh(I) complex, [( Bu C i C i C Bu )RhCl(µ-Cl) 2 Rh(COD)] ( 7 ). The catalytic system displays wide substrate scope. Electron rich and electron deficient vinylarenes were well tolerated affording the corresponding alkenylsilanes in good yields (65–86 %). Preliminary mechanistic investigations indicated that the Rh(III) center was responsible for the catalytic performance.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.