Cobalt-catalyzed condensation of sulfonyl azides with o-diisocyanoarenes and anilines: a new approach to N-sulfonyl guanidines

A novel method for the synthesis of N-sulfonyl guanidines is reported using a cobalt-catalyzed cascade reaction of sulfonyl azides with o-diisocyanoarenes and anilines. Co(iii)-nitrene is easily generated from a Co(ii) complex and a sulfonyl azide and further reacts with o-diisocyanoarenes and anilines. In this multicomponent reaction, o-diisocyanoarenes serve as C1 building blocks, instead of engaging in a dual insertion process, allowing for the construction of N-sulfonyl guanidines.