Synthesen mit verbindungen R 3MHgMR 3 und (R 2MHg) n (M = C, Si, Ge, Sn) : VII. Reduktive silylierung von Azoverbindungen und N-heterocyclen mittels bis(trimethylsilyl)quecksilber

Abstract

Me 3SiHgSiMe 3 (I) adds to the azo groups of azodiethyldicarboxylate, 2,2′-azodipyridine and azobenzene yielding N, N′ -bissilylated hydrazo compounds. N-Heterocycles are reductively N-silylated. Reactions where molar ratios of 1 2 are taken, lead in the case of pyridine, 2- and 4-methylpyridine, and quinoline to the corresponding N, N′-bissilyl-1,1′,4,4′-tetrahydro-4,4′-dipyridines, and in the case of isoquinoline to N, N′-bissilyl-1,1′,2,2′-tetrahydro-1,1′-diisoquinoline. The 1 1 molar reaction with pyrazine leads to N, N-bissilyl-1,4-dihydropyrazine. In all cases (I) apparently behaves as a nucleophile; the mercurated intermediates are thermally unstable and form (in part after symmetrisation) the final products mentioned. The yields are high. Me 3SiCl and Li react in THF with some pyridines under certain conditions to give the same products as are given by (I).