Access to four-membered cyclic sulfinamides by energy transfer catalysis

Synthetic transformations that advance through excited states proceed by unconventional mechanistic pathways and deliver products not accessible using ground-state chemistry. The breadth of these synthetically valuable transformations is constrained by the range of molecules—and particularly the functional groups—that can deliver productive excited states, with most methods using the same functional groups that were defined more than 100 years ago. In this work, we show that N -silyl sulfinylamines can undergo synthetically useful excited-state reactivity accessed using energy transfer catalysts and visible light. We exploit these intermediates in reactions with alkenes to form four-membered cyclic sulfinamide products. The reactions are efficient and broad in scope, and the products are advanced to sulfonamides as well as four-membered cyclic sulfonimidamides.