Disilathianes synthesis

Disilathianes, for example (SiH3)2S and [(CH3)3Si] 2S, have been prepared by several routes, namely, the reaction of iodosilane with silver8 and mercuric2 sulfides halosilanes with lithium sulfide,7 [NH4]SH,9 and [Me3NH]SH7 disilaselenane with H2S10 and trisilylphosphine with sulfur.10 Recently, the synthesis of hexamethyldisilathiane, [(CH3)3Si] 2S, was described from the protolysis of l-(trimethylsilyl)imidazole with H2S and from the dehydrohalogen-ation of chlorotrimethylsilane and H2S with a tertiary amine.11 Both of these methods require about 18 hours. 

The synthesis of isothiazole-fused sulfone 265 is based on the same approach and was obtained from sulfolene 520 (see Section 4.05.7.3) <1996TL4189>. Treatment of different heterocyclic n-azidocarbaldehydes with hexamethyl-disilathiane (HMDST) in the presence of HCl as catalyst offers a novel and practicable route to fused isothiazoles 521-523 <1997PS(120)165, 2005SL1965, 2000EJ02171>. 

Non-symmetrically substituted hexaorganyldisilathianes can be synthesized from halotriorganylsilanes and sodium triorganylsilanethiolate (equation 381)420. A convenient way to accomplish the synthesis of symmetrical disilathianes (733) with bulky... 

The synthesis of hexamethyldisilathiane from sodium sulfide and chloro-trimethylsilane is described here. The present method is based on the convenient in situ syntheses of alkali metal selenides and diselenides. Commercial sodium sulfide or lithium sulfide are reported to be poor substitutes for in situ generated sulfides in this reaction. For example, in 1961 Abel reported that disodium sulfide reacts with chlorotrimethylsilane in pressure vessels at 250°C for 20 h to produce I. Our procedure is very convenient, utilizing readily available starting materials and apparatus under mild conditions. The yields are t3q)ically 80-88% at 0.3-mol scale. However, it can be improved to 90-95% on small scale ( 50-mmol) reactions. This procedure can be applied to the synthesis of various disilathianes. 

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