Spirocyclic Sultam and Heterobiaryl Synthesis through Rh-Catalyzed Cross-Dehydrogenative Coupling of N-Sulfonyl Ketimines and Thiophenes or Furans

A useful approach is developed for the synthesis of various structurally interesting spirocyclic sultams and heterobiaryls using a cross-dehydrogenative coupling strategy that features high atom and step economy. This method employs [Cp*RhCl2](2) as a catalyst and N-sulfonylimine, a weak coordinating group, as an efficient directing group to assist C-H activation. A number of the coupled products were converted into interesting molecules through further synthetic transformations.