Preparation of zwitterionic hydroquinone-fused [1,4]oxazinium derivatives via a photoinduced intramolecular dehydrogenative-coupling reaction.

A simple and efficient photochemical reaction can be performed to construct functionalized [1,4]oxazinium derivatives via a direct dehydrogenative coupling between sp(3)- and sp(2)-hybridized C-atoms, starting from easily accessible stable semiquinone radicals.