Reactions of sulfenamides with alkynes in the presence of phosphorus(V) oxohalides

Article abstract of DOI:10.1007/BF02494922

The reactions of alkynes with arylsulfenamides activated with phosphorus oxohalides giving rise to aryl β-halovinyl sulfides were investigated. The reactions with acetylene, oct-1-yne, and oct-4-yne are trans-stereospecific, whereas the reaction with phenylacetylene afforded a mixture of cis- and trans-addition products. The addition to unsymmetrical alkynes yielded a mixture of Markovnikoff and anti-Markovnikoff isomers whose ratio depends on the solvent. Products of addition to oct-1-yne in the presence of catalytic amounts of acids underwent isomerization.