Silanethiols silanes

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). 

FIGURE 20. Bond lengths in silanethiol derivatives (left) and Si—S—X bond angles in acyclic silan-ethiol derivatives (right)... 

Examples of application of the iert-dodecanethiol/silane couple include typical reductive dehalogenations, but also Barton-McCombie deoxygenations of alcohols, through conversion of the latter into xanthate esters (eq 6), hydrosilylations of alkenes (eq 7), and preparation of silanethiols. The thiol can also be used as a polarity reversal catalyst in conjunction with tris(trimethylsilyl)silane and hexabutyldistannane/malonic acid. ... 

Without additional reagents Silanethiols from silanes... 

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