Silastannation alkynes

Palladium-catalyzed addition of a silicon-tin linkage across a carbon-carbon triple bond was first reported in 1985 by the Mitchell group and the Ghenard group independently.251,252 Since then, the silastannation reaction of alkynes has been studied extensively (Table J) 25S 261... 

The palladium-isocyanide complex is effective for silastannation of ethoxyethyne, a labile alkyne, to produce (Z)-1-ethoxy-l-silyl-2-stannylethene with high regioselectivity (Equation (106)).253 The regioselectivity observed has also been studied by computation.263... 

A thermodynamically stable (silyl)(stannyl)palladium(n) complex is synthesized by an oxidative addition of the Si-Sn linkage to palladium(O) (Scheme 63).267 The complex has the square-planar geometry with a m-arrangement of the silicon and tin atoms. An alkyne reacts with the complex to afford a silastannated product as a mixture of cisjtrans stereoisomers (10 1). 

Silastannation similarly appears to involve intermediates based on Si-PdL -Sn complexes, the rate-determining step being the insertion of the alkyne into the Sn-Pd bond (Equation (32)). 

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