Cobalt-Catalyzed Three-Component Synthesis of Sulfoximine-Containing Guanidines: Retention of the High-Valent S(VI) Sulfoximine Motif.

We have developed a cobalt(II)-catalyzed three-component coupling of sulfoximines, isocyanides, and sulfonyl azides for the synthesis of sulfoximine-containing guanidines. The method features operational simplicity, broad substrate applicability, and good functional group tolerance. In this work, "protection" refers to retention of the high-valent S(VI) sulfoximine motif during guanidine construction rather than introduction of a conventional removable protecting group.