Bromonium-Catalyzed Diamination of Various Conjugated Alkenes

Cyclic halonium-mediated reactions using alkenes feedstocks are a classic but excellent method to control stereochemistry. Since halogeno groups inevitably remain in the products, it is theoretically impossible to make the reaction catalytic. If the halogeno groups can be liberated and oxidized in the reaction process, not only can the reaction be catalyzed, but other useful functional groups can be introduced into alkenes. Here we report the bromonium-catalyzed intermolecular diamination of a,b-unsaturated carbonyl compounds and aromatic ring-fused alkenes. N,N-Dibromo-2-nitrobenzenesulfonamide (dibromamine-Ns) was found to be a potential catalyst for the generation of cyclic bromonium species. N-Chloro-N-sodio-2-nitrobenzenesulfonamide (chloramine-Ns) acted as both nitrogen sources and as an oxidant for the returning catalyst. This protocol offers an efficient and operationally straightforward platform for the simultaneous installation of two vicinal carbon-nitrogen bonds from alkenes. The method demonstrates a broad 2 substrate scope and excellent stereoselectivity, thereby enabling access to structurally diverse and pharmaceutically relevant building blocks.