Thermoinduced Free-Radical C-H Acyloxylation of Tertiary Enaminones: Catalyst-Free Synthesis of Acyloxyl Chromones and Enaminones.

In this paper, the direct acyloxylation of the α-C(sp2)-H bond in tertiary β-enaminones is accomplished under catalyst-free conditions and ambient temperature by using aroyl peroxides as coupling partners. By means of a thermoinduced free-radical pathway, the present method enables facile and efficient synthesis of both acyloxylated chromones and enaminones.