Silanimines, synthesis

Scheme 1. Iron-substituted Silanimines. Synthesis and Reactions with Alcohols, Amins and Acetone.

The synthesis of silanimines by salt elimination has been independently developed in the laboratories of Klingebiel304-307. An example of the synthesis of a stable donor adduct (681) is shown in equation 222 and equation 223 illustrates the general dimerization... 

The detection of the r-BuOH trapping product 703 and of the dimer 746 gives further evidence for the intermediacy of 744 and 745, respectively. Silanimine 735 is an intermediate in the synthesis of silaisocyanide 737 by retro-ene reaction from 747 under FVT conditions (equation 246)333. 737 was characterized by millimeter wave spectroscopy. 

As mentioned in this chapter, in recent years much progress has been made in the chemistry of silicon-chalcogen multiple bonds. For silicon-sulfur doubly-bonded compounds, we have now several isolated examples, both kinetically stabilized and thermodynamically stabilized. Furthermore, there have been reports of the synthesis and characterization of stable compounds with silicon-nitrogen double bonds (i.e. silanimines or iminosilanes) as well as their heavier group 15 element analogues such as phosphasilenes and arsasilenes. 

For the formation of cyclodisilazanes by salt elimination from silylamides =Si(X)-N(M)-(X = halogen, H M = alkali metal) two routes are discussed (i) intramolecular MX elimination and dimerization of the formed silanimine, (ii) intermolecular MX elimination to an intermediate =Si(X)-N(-)-Si(=)-N(M)- that immediately cyclizes with MX elimination [1-5]. The hydridosilylamides Me2(H)SiNLiR (R = Me2(H)Si, Me2CH, CMej) and RR (H)SiNLiSiMe3 (R, R = Me R = MesSiNH, Me3SiNLi, R = Me) react with MesSiCl in THF to give A -substitution products and in -hexane to form 1,3-cyclodisilazanes, formation of which has been explained via route (i) [6, 7], However, the silanimine has not been detected experimentally, Here we describe the synthesis of new hydridosilylamides and the reaction of these compounds and known hydridosilylamides with MesSiCl. 

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