Aminochlorination of Alkenes with CFBSA

A novel catalyst‐free aminochlorination of alkenes was developed by the direct addition of alkenes to N ‐chloro‐ N ‐fluorobenzenesulfonamide (CFBSA). The reaction produces 2‐chloro‐3‐fluoramino and 3‐chloro‐2‐fluoroamino adducts in 1,2‐dichloroethane under reflux and dichloromethane at room temperature, respectively, in a regioselective manner. The electronic and steric effects of the fluorine atom of CFBSA have proven to be crucial for the reactivity and regioselectivity. A variety of transformations have been achieved to form 2‐chloroenamines, chloroamines, aziridines and N ‐phenylbenzenesulfonamides under different conditions. Notably, the N–F bond in the adducts formed could be a useful handle for further transformations to useful compounds in organic synthesis.