Et3B-induced radical addition of N,N-dichlorosulfonamide to alkenes and pyrrolidine formation via radical annulation.

TLDR: A radical annulation reaction among N,N-dichlorosulfonamide, 1,3-dienes, and alkenes has been developed and N-chloro-N-allylamides thus obtained react with a variety ofAlkenes to furnish pyrrolidine derivatives in good yields.

Abstract: A highly regioselective radical addition of N,N-dichlorobenzenesulfonamide (dichloramine-B) to 1-alkenes is achieved at −78 °C by the use of triethylborane as a radical initiator. The reaction of 1,3-dienes with N,N-dichlorosulfonamide in the presence of Et3B regioselectively provides N-chloro-N-allylamide derivatives. N-Chloro-N-allylamides thus obtained react with a variety of alkenes to furnish pyrrolidine derivatives in good yields. A radical annulation reaction among N,N-dichlorosulfonamide, 1,3-dienes, and alkenes has been developed.