Unexpected halogen exchange with halogenated solvents in the iron(III) promoted oxa-alkyne and aza-alkyne Prins cyclizations

Abstract

An unexpected halide exchange with halogenated solvents using iron(III) halides as promoters in oxa- and aza-alkyne Prins cyclizations have been observed. The process is specific for alkynes, while during the Prins cyclization using both homoallylic alcohols and N-tosyl amines, the halide participation from the halogenated solvent was absent. Calculation at ab initio level provides substantiation of the proposed model. ©ARKAT USA, Inc.