This work reports a cobalt(II)/ N-hydroxyphthalimide (NHPI)-catalyzed cross-dehydrogenative oxidative coupling of N-aryl tetrahydroisoquinolines with various pro-nucleophiles, such as indoles, nitroalkanes, and trialkylphosphites, active methylene compounds, and other nucleophiles, such as cyanide (ethyl cyanoformate), at room temperature under aerobic conditions. The present protocol is operationally simple and can be carried out without photoirradiation and under peroxide-free conditions, even on a gram scale, to afford the products in good to excellent yields. On the basis of mass spectrometry and control experiments, a catalytic reaction pathway has been proposed.