Dual C-H functionalization of N-aryl tetrahydroisoquinolines: a highly diastereoselective synthesis of dibenzo[a,f]quinolizines via visible-light induced oxidation and inverse electron-demand aza-Diels-Alder reaction.

Described herein is the first example of the application of an iminium intermediate generated by visible-light photocatalyzed oxidation in an inverse electron-demand aza-Diels-Alder reaction. This dual functionalization of both C(sp(3))-H and C(sp(2))-H bonds of N-aryl tetrahydroisoquinolines represents a valuable example for access to polycycles with high diastereoselectivity.