Synfacts 2005(0): 0024-0024  
DOI: 10.1055/s-2005-865366
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

Generation and Aromaticity of 2-Silaimidazo-lium Ion, a New π-Conjugated Silylium Ion

Contributor(s): Victor Snieckus, Robert Engqvist
S. Ishida, T. Nishinaga, R. West, K. Komatsu
Kyoto University, Japan
Generation and Aromaticity of 2-Silaimidazolium Ion, a New π-Conjugated Silylium Ion
Chem. Commun.  2005,  778-780  
Further Information

Publication History

Publication Date:
20 July 2005 (online)


Significance

The 2-silaimidazolium ion, a new kind of heterocylic aromatic cation has been generated from the corresponding chlorosilane by a chloride abstraction using Et3Si(benzene) tetrakis(pentafluorophenyl)borate. The silaimidazolium ion is stable at temperatures below -10 °C and was fully characterized by 1H, 13C and 29Si NMR parameters which were compared with theoretical calculations [29Si NMR 53.0 (CD2Cl2) and 53.2 (C7D8) for the 2-silaimidazolium compared to the chlorosilane (-17.7 in CD2Cl2)].

Comment

Silylene compounds have been a focus of structural interest for the last ten years (B. Tumanskii, P. Pine, Y. Apeloig, N. Hill, R. West J. Am. Chem. Soc. 2004, 126, 7786-7787). However, this represents the first synthesis and full characterization of a silaimidazolium ion which will undoubtedly trigger studies on scope and limitation of the synthetic route and reactivity, as well as efforts to derive new silanimine systems. For simple Si=N derivatives, see N. Wiberg, K. Schurz J. Organomet. Chem. 1988, 341, 145-164.