A copper-catalyzed decarboxylative aminomethylation of indole-3-carboxylic acids with 1,2-oxazetidines has been developed, enabling the rapid synthesis of structurally diverse 3-aminomethylindoles in good to excellent yields. Remarkably, an unprecedented decarboxylative aminomethylation/cyclization cascade was further achieved by a combination of copper and iron salts to construct complex γ-carbolines with high efficiency. It is worth noting that one of the obtained products proved to be a good dual-emissive luminogen, exhibiting both aggregation-caused quenching and aggregation-induced emission.