Sulfondiimines, which are isoelectronic with sulfones and sulfoximines, represent a neglected yet intriguing pharmacophore in the discovery program. Herein, we present a facile and mild photocatalytic anti-Markovnikov hydroamination of styrenes for the construction of N-alkylated sulfondiimines with primary, secondary, and tertiary alkyl substituents. A sulfondiimine-derived analogue of the marketed drug Vioxx was synthesized using this method as the key step.