Abstract Nucleophilic substitution reaction of halogen atom in β-chloro-and β-bromo-β- trifluoromethylstyrenes by thiolates was studied. Stereo-and regioselectivity of the reaction with respect to the electronic and sterical properties of substituents in the aromatic ring of starting styrenes was investigated. Regioisomer with geminal trifluoromethyl and alkyl-or arylthio groups was found to be formed predominantly or exclusively. The reaction ...