I. Kalikhman, O. Girshberg, L. Lameyer
Apr 13, 2000
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0
Influential Citations
13
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Journal
Organometallics
Abstract
The reaction of (chloromethyl)trichlorosilane (7) with O-trimethylsilylated N,N-dimethylhydrazides yields initially under kinetic control, in nearly quantitative yields, a neutral hexacoordinate bis(N→Si) chelate, bis(N-(dimethylamino)acylimidato-N,O)chloro(chloromethyl)silicon(IV) (8a−c). Upon heating, the octahedral complexes 8 are quantitatively and irreversibly converted to the isomeric hexacoordinate chelates zwitterionic λ6-silicates 9a−c, (N-(dimethylamino)acylimidato-N,O)(1-((1,1-dimethyl-2-acyl)hydrazonium)methyl-C,O)dichlorosilicon(IV). This molecular rearrangement is rather unusual, since it involves chelate-ring expansion from the common five-membered ring to a six-membered ring in the thermodynamically favored product 9. 8b and 9b were characterized by X-ray crystal analyses and in solution by their 1H, 13C, and 29Si NMR spectra. The analogous compounds 8a,c and 9a,c were characterized by the respective analogy of their NMR spectra. Both 8b and 9b have slightly distorted octahedral geometries...