Reported herein is a novel visible‐light photoredox system with Pd(PPh3)4 as the sole catalyst for the realization of the first direct cross‐coupling of C(sp3)−H bonds in N‐aryl tetrahydroisoquinolines with unactivated alkyl bromides. Moreover, intra‐ and intermolecular alkylations of heteroarenes were also developed under mild reaction conditions. A variety of tertiary, secondary, and primary alkyl