Reaction of N-heterocyclic silylenes with thioketone: formation of silicon-sulfur three (Si-C-S)- and five (Si-C-C-C-S)-membered ring systems.
Three- and five-membered rings that bear the (Si-C-S) and (Si-C-C-C-S) unit have been synthesized by the reactions of LSiCl (1; L=PhC(NtBu)2 ) and L'Si (2; L'=CH{(CCH2 )(CMe)(2,6-iPr2 C6 H3 N)2 }) with the thioketone 4,4'-bis(dimethylamino)thiobenzophenone. Treatment of 4,4'-bis(dimethylamino)thiobenzophenone with LSiCl at room temperature furnished the [1+2]-cycloaddition product silathiacyclopropane 3. However, reaction of 4,4'-bis(dimethylamino)thiobenzophenone with L'Si at low temperature afforded a [1+4]-cycloaddition to yield the five-membered ring product 4. Compounds 3 and 4 were characterized by NMR spectroscopy, EIMS, and elemental analysis. The molecular structures of 3 and 4 were unambiguously established by single-crystal X-ray structural analysis. The room-temperature reaction of 4,4'-bis(dimethylamino)thiobenzophenone with L'Si resulted in products 4 and 5, in which 4 is the dearomatized product and 5 is formed under the 1,3-migration of a hydrogen atom from the aromatic phenyl ring to the carbon atom of the CS unit. Furthermore, the optimized structures of probable products were investigated by using DFT calculations.
Institut für Anorganische Chemie der Universität Göttingen, Tammannstrasse 4, 37077 Göttingen, Germany.
Ramachandran
R
Azhakar
Rajendra S
RS
Ghadwal
Herbert W
HW
Roesky
Ricardo A
RA
Mata
Hilke
H
Wolf
Regine
R
Herbst-Irmer
Dietmar
D
Stalke
D018360:Crystallography, X-Ray; D006571:Heterocyclic Compounds / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis* / Q000737:chemistry*
D006571:Heterocyclic Compounds; D007659:Ketones; D017646:Organosilicon Compounds; D013438:Sulfhydryl Compounds