Cyclocarbonylation of silicon tethered enynes derived from propargylic alcohols and vinylsilanes: a new reductive Pauson–Khand reaction with a traceless tether

In nitrile solvents vinylsilyl ethers of propargylic alcohols undergo Pauson–Khand reaction with polysiloxane extrusion and concomitant reduction of the propargylic CO bond. The product enones are formally the result of an intermolecular PKR reaction with ethylene.