An unprecedented method for the direct arylation and heteroarylation of tetrahydroisoquinolines under metal and oxidant free conditions is reported. The arylation reactions occurred via a C(sp³)–H functionalization enabled three component condensation of tetrahydroisoquinolines, 9-fluorenone imine, and arenes without involving a pre-functionalization/pre-derivatization step. A wide range of arenes and heteroarenes participated in the reaction to provide structurally diverse arylated tetrahydroisoquinolines with good to excellent yields.