The Domino Chromone Annulation and a Transient Halogenation-Mediated C-H Alkenylation toward 3-Vinyl Chromones.

Reported in this paper is a step economical method toward the general synthesis of 3-vinyl chromones via the reactions between readily available o-hydroxyphenyl enaminones and various alkenes. The domino C-H alkenylation and chromone annulation of the enaminones are involved, which enables the synthesis of 3-vinyl chromone products using both terminal and internal alkenes via a key process of transient C-H halogenation.