An efficient synthesis of dihydro-isoquinolines via a Pd–catalyzed double C–H bond [a C(sp²)–H and a C(sp³)–H bond] activation/annulation (CHAA) reaction is presented. This methodology features a short reaction time, high atom economy (loss of H₂O only) and the formation of a sterically less favoured tertiary C–N bond. This fast (30 min) and environmentally benign radical C–H activation approach has demonstrated the potential direction for the future design/development of fast and efficient C–H direct functionalization processes.