Free and Coordinated Iminosilanes: Synthesis and Structures.
In: Organometallics, Jg. 17 (1998) ; Nr. 5, S. 947-953
Zeitschriftenaufsatz / Fach: Chemie
The uncoordinated and thermally stable iminosilane (Me3C)2Si:NSi(CMe3)2Ph (1) is formed quant. in the reaction of the lithiated aminofluorosilane and Me3SiCl with subsequent elimination of Me3SiF and LiCl. Di-tert-butyldifluorosilane and diisopropyldifluorosilane react with lithiated amino-tert-butyldiisopropylsilane and amino-di-tert-butylphenylsilane to give the aminofluorosilanes (Me3C)2FSiNHSi(CHMe2)2CMe3 (2) and (Me2HC)2FSiNHSi(CMe3)2Ph (3). 2 And 3 are converted into their lithium derivs. (Me3C)2FSiNLi(THF)2Si(CHMe2)2CMe3 (4) and (Me2HC)2FSiNLi(THF)2Si(CMe3)2Ph (5) with nBuLi. 4 Reacts with Me3SiCl to give Me3SiF and the lithiated aminochlorosilane. Thermal LiCl elimination leads to the formation of the iminosilane (Me3C)2Si:NSi(CHMe2)2CMe3 (6). A fluorine-bromine exchange occurs when 5 is treated with Me3SiBr in THF/toluene. In a subsequent LiBr elimination (Me2HC)2(C4H7O)SiNHSi(CMe3)2Ph (7) is obtained. 1 And 6 form the THF adducts (Me3C)2(THF)Si:NR (8, R = Si(CMe3)2Ph; and 9, R = Si(CHMe2)2CMe3). The adducts (Me3C)2(py)Si:NR (10, R = Si(CMe3)2Ph; and 11, R = Si(CHMe2)2CMe3) are formed when pyridine is used as a donor. At 50 Deg in toluene 10 and 11 decomp. under Stevens migration into (Me3C)2(2-py)SiNHR (12, R = Si(CMe3)2Ph; 13, R = Si(CHMe2)2CMe3). In the reaction of 1 with 2-cyclohexen-1-one the ene reaction product (Me3C)2(C6H7O)SiNHSi(CMe3)2Ph (14) is formed. X-ray crystal structure detns. are presented for 1, 9, 10, and 11.