Metal-Free Oxidative <i>Ipso</i>-Carboacylation of Alkynes: Synthesis of 3‑Acylspiro[4,5]trienones from <i>N</i>‑Arylpropiolamides and Aldehydes

Abstract

A general and metal-free radical route to synthesis of 3-acylspiro­[4,5]­trienones is established that utilizes TBHP (<i>tert</i>-butyl hydrogenperoxide) as an oxidation and a reaction partner to trigger the oxidative <i>ipso</i>-carboacylation of <i>N</i>-arylpropiolamides with aldehydes. This method offers a new difunctionalization of alkynes through oxidative cross coupling of the aldehyde C­(sp²)–H bond with an <i>ipso</i>-aromatic carbon