Intramolecular Ring Expansion of 3-Silaazetidine with Alkynes Enabled by Pd-Catalyzed Si-C Bond Activation.

An intramolecular ring expansion of in situ formed 3-silaazetidine with internal alkynes has been developed via Pd-catalyzed Si-C bond activation. The reaction gives rise to 6,5- and 6,6-fused bicyclic 1,3-azasilines, in which the silicon atom locates at the ring junction position.