Allylic Halogenation of α-Olefin with N-Halosulfonamide

Abstract

The reaction of 1-olefins with N-halo-N-tert-butyl and N-cyclohexyl-ethanesulfonamide was investigated. In this reaction, allylic hydrogen abstraction occurred and monohalogenated olefin was obtained in high yield, and no 1 : 1 adducts were formed because of the steric effect of N-tert-butyl or N-cyclohexyl group. Especially N-chloro derivative of N-tert-butyl or N-cyclohexylethanesulfonamide was effective for the allylic chlorinating reagent.The reaction of N-haloethanesulfonamide with excess of 1-olefin at 130°C in the presence of BPO was suitable to proceed allylic halogenation in high yield. The isomer ratio of 1-halo-2-olefin to 3-halo-1-olefin was determined, and its isomer ratio decreased with the increase of alkyl chain length of 1-olefin. The larger amounts of 1-halo-2-olefin was formed in the reaction of N-bromo-N-tert-butylethanesulfonamide with 1-olefin than that in the reaction of N-chloro-N-tert-butylethanesulfonamide.