Dual C(sp 3 )-H and C(sp 2 )-H Activation of 8-Methylquinoline N -Oxides: A Route to Access C7-H Bond.

A Pd(II)-catalyzed regioselective dual C(sp 3 )-H/C7(sp 2 )-H activation and annulation of 8-methylquinoline N -oxides with maleimide has been accomplished. The use of N -oxide as a weak directing group under Pd(II)-complex catalysis activates the initial C(sp 3 )-H and triggers a relayed, second C7(sp 2 )-H activation. The dual C-H bond activation, [3 + 2]-annulation, facile introduction and removal of the directing group, substrate scope, and functional group diversity are the important practical features.