The reaction of secondary amines R'RNH with trimethyaluminum leads to the formation of dimeric aminoalanes [RR'NAIMe(2)](2) (1) (R = 2,6-Me2C6H3, R' = SiMe2(2,4,6-Me3C6H2)) and 2 (R = Ph, R' = SiMe3). Using a different stoichiometric ratio, a monomeric aminoalane [RR'N](2)AlMe (3) (R = Ph, R' = SiPh2Me) is obtained, having an aluminum atom of coordination number three due to the steric demand of the substituents. The synthesis of the corresponding aminogallanes 4, 5 and 6 is achieved by reaction of lithium amides LiNRR' (R = Ph, 2,6-iPr(2)C(6)H(3); R' = SiMe3, SiMe(2)iPr) with dimethylgalliumchloride, Me2GaCl, in n-hexane. The formation of the dimeric species is in 1 through carbon while that in 2 and 3 is formed through nitrogen. The X-ray single crystal structure analysis of 1, 2, 3 and 4 are reported.
The 15N–29Si spin–spincouplingconstants in silylamines have been measured from 29Si satellites in their natural abundance 15N n.m.r. spectra in an INEPT sequence for accumulation of signals and interpreted in terms of Fermi-contact interaction; the sensitivity of 1J(15N–29Si) to dπ–pπ bonding was noted.
The B(C6F5)3 catalyzed cross-dehydrocoupling of hydrosilanes with anilines, carbazoles and indoles is reported and provides a metal-free access to silyl-protected amines.
The reaction of secondary amines R'RNH with trimethyaluminum leads to the formation of dimeric aminoalanes [RR'NAIMe(2)](2) (1) (R = 2,6-Me2C6H3, R' = SiMe2(2,4,6-Me3C6H2)) and 2 (R = Ph, R' = SiMe3). Using a different stoichiometric ratio, a monomeric aminoalane [RR'N](2)AlMe (3) (R = Ph, R' = SiPh2Me) is obtained, having an aluminum atom of coordination number three due to the steric demand of the substituents. The synthesis of the corresponding aminogallanes 4, 5 and 6 is achieved by reaction of lithium amides LiNRR' (R = Ph, 2,6-iPr(2)C(6)H(3); R' = SiMe3, SiMe(2)iPr) with dimethylgalliumchloride, Me2GaCl, in n-hexane. The formation of the dimeric species is in 1 through carbon while that in 2 and 3 is formed through nitrogen. The X-ray single crystal structure analysis of 1, 2, 3 and 4 are reported.
Zinc-Catalyzed Dehydrogenative Silylation of Indoles
to the corresponding C-silylation in the case that the nitrogen atom of indoles has a substituent. Pyrrole, carbazole, arylamine, and thiophene substrates other than indoles undergo the dehydrogenative N- and/or C-silylation as well. Mechanistic studies showed that the role of the zinc Lewis acid is to activate the hydrosilane. The rate-determining step of the present reaction was found to be involved