The rhodium(iii)-catalyzed C(sp3)-H amination reaction of 8-methylquinolines and azodicarboxylates is described. A cationic rhodium catalyst in the presence of lithium acetate and lithium carbonate was found to be an optimal catalytic system for the construction of quinolin-8-ylmethanamine derivatives, which were evaluated for in vitro cytotoxicity against human breast adenocarcinoma cells (MCF-7) and human prostate adenocarcinoma cells (LNCaP).