Practical Synthesis of α,β-Alkynyl Ketones by Oxidative Alkynylation of Aldehydes with Hypervalent Alkynyliodine Reagents

A practical, metal-free carbonyl C(sp2)–H oxidative alkynylation of aldehydes with hypervalent alkynyliodine reagents without the use of any catalysts is described for the synthesis of various α,β-alkynyl ketones. Here, two different methods have been developed where limiting reagents or substrates can be switched, and adopted according to the valuableness of aldehyde substrates or hypervalent alkynyliodine reagents. These reactions proceed with a broad substrate scope and high functional-group compatibility. A practical, metal-free carbonyl C(sp2)–H oxidative alkynylation of aldehydes with hypervalent alkynyliodine reagents without the use of any catalysts is described for the synthesis of various α,β-alkynyl ketones. Here, two different methods have been developed where limiting reagents or substrates can be switched with each other, and adopted according to the valuableness of aldehyde substrates or hypervalent alkynyliodine reagents.