Mechanistic study of multi-step nucleophilic substitution for trifluoromethylated styrenes

The key steps of the reactions of nitrogen nucleophiles with β-halogen-β-trifluoromethylstyrenes have been studied by 19F and 1H NMR monitoring and quantum-chemical calculations. In contrast to the mechanism proposed earlier for nucleophilic vinylic substitution of captodative carbonyl-bearing haloalkenes, this reaction proceeds via either E–Ad or Ad–E sequence depending on the nature of aromatic substituents of the parent styrenes.

Graphical abstractThe key steps of the reactions of nitrogen nucleophiles with β-halogen-β-trifluoromethylstyrenes have been studied by 19F and 1H NMR monitoring and quantum-chemical calculations. In contrast to the mechanism proposed earlier for nucleophilic vinylic substitution of captodative carbonyl-bearing haloalkenes, this reaction proceeds via either E–Ad or Ad–E sequence depending on the nature of aromatic substituents of the parent styrenes.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The reaction of amines with β-halogen-β-trifluoromethylstyrenes was studied by 19F and 1H NMR monitoring. ► It was found that the reaction can proceeds either E–Ad or Ad–E sequence. ► The reaction route is determined by the nature of aromatic substituents of the starting styrenes.