An iodine-catalyzed Ritter-type amination of nonactivated C–H bonds is presented enabling the formation of 1,3-α-tertiary diamines. A sulfamidyl radical serves as the promoter in a guided tertiary C–H iodination through an exclusive 1,6-HAT process. The subsequent Ritter reaction furnishes the C–N bond and establishes an unprecedented concept for catalyst turnover in iodine redox catalysis. The general robustness of the methodology, including broad functional group tolerance, was demonstrated for 24 different 1,3-diamine derivatives, which were synthesized in yields of 42%–99%.