Silanethiols synthesis

The addition of trisubstituted silanes to carbonyl sulfide has been applied to the synthesis of the corresponding silanethiol derivatives (Reaction 5.40) [78]. In Scheme 5.12 the mechanism is depicted, starting from the silyl radical attack to the sulfur atom of 0=C=S and ejection of carbon monoxide. The resulting silanethiyl radical abstracts hydrogen from the starting silane, to give the silanethiol and to generate fresh silyl radical (see Section 3.4). 

Reductions with tris(trimethylsilyl)silanethiol 18 [38J and with heptamethyltrisilane-2-thiol 19 [39] are also effective, but again the cost of these reagents would be prohibitive per hydrogen delivered for larger-scale synthesis. 

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