Synthetic uses of ynolates

The synthetic uses of ynolates, including silyl ynol ethers, that has the ability to synthesize another reactive species are investigated. An ynolate, a nucleophile, reacts with an electrophile to give a ketene, an electrophile, which reacts with a nucleophile to afford an enolate, a nucleophile. Metalation of the precursors of ketenes, followed by transformation into the metalated ketenes, would be a better route to ynolates. An efficient method for the synthesis of ynolates has been developed which are easily converted into ketenes by elimination of alkoxides. Ynolate anions initiate a negative-positive switching cascade process, torquoselective olefination, and heterocyclization, and silyl ynol ethers act as functional electron-rich triple bond and ketenium precursors.