Three-Component Ring-Opening Reactions of Cyclic Ethers, α-Diazo Esters, and Weak Nucleophiles under Metal-Free Conditions.

A protocol for three-component reactions of cyclic ethers, α-diazo esters, and weak nitrogen, oxygen, carbon, and sulfur nucleophiles (p Ka = 2.2-14.8) to afford a variety of structurally complex α-oxyalkylated esters is reported. These reactions involve intermolecular activation of the cyclic ether (present in excess) by the α-diazo ester to form an oxonium ylide under metal-free conditions, followed by ring opening by the nucleophile.