Silylenes with isothiocyanates

As in the case of silanone 9, the reaction of the silylene bis[2-(dimethylamino-methyl) phenyl]silanediyl (8) with phenyl isothiocyanate was examined.29 In this reaction the expected silanethione 36 was obtained as a single product even in the presence of (Me2SiO)3, no insertion product of 36 into a Si-O bond of (Me2SiO)3 was observed (Scheme 10). 

In recent years remarkable progress has been made in the chemistry of organosilicon compounds containing a double bond to group 14 and group 15 elements. The reaction of a silylene-isocyanide complex with nitrile oxide generated the intermediate silanone, which with phenyl isothiocyanate afforded 1,3,2-oxathiasiletane 63, which is sensitive to hydrolysis (Equation 10) <2000CL244>. 

The silylene 79 abstracts oxygen or sulfur from isocyanates and isothiocyanates. Cyclic sUoxanes are the products with isocyanates (equation 129) these probably arise by polymerization of the silanone, Ar2Si=0 (83). 

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