On the Behavior of Sulfonyl Imide as a Reactive Intermediate. The Reaction with Enamines

Abstract

Abstract The reactions of N-alkylsulfamoyl chloride with enamines in the presence of triethylamine showed the presence of N-alkylsulfonyl imide (RN=SO2) as a reaction intermediate to give either acyclic (sulfonamides) or cyclic products (1,2-thiazetidine 1,1-dioxides), depending upon the enamines used. The enamines leading to the acyclic products possess either a methylene group on the α-carbon or a hydrogen on the β-carbon of the enamine; the enamine leading to the cyclic product has no such available hydrogen atom. It is thought that the products are formed via a zwitter ionic intermediate provided by the electrophilic attack of the sulfonyl imide sulfur atom on the β-carbon atom of the enamine.