A Metal-Free Oxidative Dehydrogenative Diels-Alder Reaction for Selective Functionalization of Alkylbenzenes

Functionalization of C(sp³ )-H bonds under metal-free reaction conditions is a great challenge due to poor bond reactivity. A novel metal-free oxidative dehydrogenative Diels-Alder reaction of alkylbenzene derivatives with alkenes through C(sp³ )-H bond functionalization is described. The developed oxidative method provides a straightforward approach to biologically relevant 1,4-phenanthraquinone and isoindole derivatives from readily available starting materials. Furthermore, the synthesis of nitrostyrenes from enylbenzene derivatives by selective C(sp³ )-H bond functionalization has been demonstrated.