Ethylene-promoted intermolecular enyne metathesis.Org Lett. 2003 Oct 16; 5(21):3819-22.OL
[reaction: see text] Intermolecular enyne metathesis between functional group-rich alkynes and vinyl ethers was promoted by ethylene cometathesis. The concentration of ethylene was optimized to suppress the competing formation of butadiene through background ethylene metathesis. The role of ethylene appears to be both protective and rate enhancing.