Rh(iii)-Catalyzed C-H activation/annulation of salicylaldehydes with sulfoxonium ylides for the synthesis of chromones

A rhodium(iii)-catalyzed C-H activation/annulation of salicylaldehydes with sulfoxonium ylides has been developed for the formation of 2-substituted chromones in good yields with broad functional group tolerance. The utility of this strategy was showcased by the late-stage modification of some biologically active molecules. Moreover, structurally diverse 2,3-disubstituted chromones were also constructed by the C3 C-H functionalization reactions.