A rhodium-catalyzed sequential oxidative C–H annulation reaction between ketazines and internal alkynes has been developed via C–H and N–N bond activation with air as an external oxidant, which led to an efficient approach toward isoquinolines with high atom efficiency at rt. Utilizing the distinctive reactivity of this catalysis, both N-atoms of the azines could be efficiently incorporated to the desired isoquinolines under very robust and mild reaction conditions.