Silole skeletons are constructed by ring-closing olefin metathesis of silicon-tethered dienes and trienes. A silicon-tethered enyne is also converted to a 2-alkenyl-1-silaindene via ruthenium-catalyzed ring-closing enyne metathesis.
A unprecedented intramolecular [2+2] cycloaddition reaction between allenes and silicon-bearing olefins is presented. This is also the first example of the reagent-controlled regioselective [2+2] cycloaddition of allenes. The products in this work were oil compounds. The crystal sponge method was successfully used to determine their structures.