The synthesis of sultams, particularly bicyclic ones, via the CSIC reaction has gained widespread use, especially over the last 10 years. The utilization of Nsulfonylated α-aminonitriles was first explored by Marco-Contelles and co-workers, and the term "CSIC reaction" was introduced to the literature in 2003, although similar reactions were published three decades earlier, including the condensation of sultams with nitriles to give enamines. This transformation proceeds analogously to intramolecular nucleophilic addition to enolates and aldol condensation of alkanesulfonates (sulfonamides) with the formation of sultones (sultams). The reaction is facilitated by the high α-CH-acidity of the methylene unit near the sulfonamide group, and in the absence of more mobile sulfonamide NH protons, which could be deprotonated first.