Computational Study for the Aromatic Nucleophilic Substitution of 4-Dimethylamino-3-trifluoroacetyl- quinoline with Various Nucleophiles

Abstract

The aromatic nucleophilic substitutions of 4-dimethylamino-3-trifluoroacetylquinoline 1 with amines, thiols, and alcohols are elucidated on the basis of DFT calculations. Our calculation results suggest that the reaction of 1 with amines giving N-N exchanged products 4 occurs via Meisenheimer type adducts V whereas the ones with thiols and alcohols proceed via the enol type adducts VII and IX to afford N-S and N-O exchanged products 8 and 9, respectively. It is also clarified that the conditions required for the successful substitution are not controlled by the activation energies on these processes, but by the energy changes on the processes from 1 to each intermediates, V, VII, and IX.