A catalyst‐free multicomponent CDC reaction is rarely reported, especially for the intermolecular tandem CDC cyclization, which represents an important strategy for constructing cyclic compounds. Herein, a three‐component tandem CDC cyclization by a Pummerer‐type rearrangement to afford biologically relevant isoindolinones from aromatic acids, amides, and DMSO, is described. This intermolecular tandem reaction undergoes a C(sp2)−H/C(sp3)−H cross‐dehydrogenative coupling, C−N bond formation, and intramolecular amidation. A notable feature of this novel protocol is avoiding a catalyst and additive (apart from oxidant). Coupling without metal! A three‐component tandem CDC cyclization by Pummerer‐type rearrangement to afford biologically relevant isoindolinones from acids, amides, and DMSO is described. This intermolecular tandem reaction undergoes a C(sp2)−H/C(sp3)−H cross‐dehydrogenative coupling, C−N bond formation, and intramolecular amidation (see scheme).