Metal-free carbonyl C(sp2)–H oxidative alkynylation of aldehydes using hypervalent iodine reagents leading to ynones.

A new metal-free tert-butyl hydroperoxide (TBHP)-mediated carbonyl C(sp²)–H oxidative alkynylation of aldehydes with ethynyl benziodoxolones (EBX) for the synthesis of ynones is described. This method is based on a carbonyl C(sp²)–H oxidative radical coupling process according to mechanistic studies, and provides a general route to the assembly of diverse ynones with a broad substrate scope and excellent functional-group compatibility. [ABSTRACT FROM AUTHOR]