Pyridine, reaction with disilenes

Cyclotrisilanes are easily converted to a mixture of silylene and disilene. Reactions of the silylene (l-Bu)2Si and the disilene l-Bu2Si=Si(Bu-l)2 produced by photolysis of the cyclotrisilane 293 with cyclopentadiene, furan, and thiophene have been reported recently152, as were their reactions with 2,2 -bipyridyl, pyridine-aldimine and ketoimines153. 

When [t-Bu2Si]3 is used as the source of t-Bu2Si, the remaining disilene adds to the 3,4-positions of one of the pyridine rings. Similar reactions are observed with a-ketoamines. 

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