Intramolecular redox reaction: Heating N‐alkyl, N‐allyl‐, and N‐benzyl‐substituted S‐alkenyl sulfoximines under appropriate conditions results in the formation of NH‐S‐alkyl sulfoximines. The intramolecular redox reaction involves a hydride transfer that occurs by a 6‐endo‐trig process. The intermediates in the reaction can also give access to four‐ and six‐membered heterocyclic rings and a new class