Abstract:
Preferential solvation in aromatic nucleophilic
substitution reactions is discussed using a kinetic study
complemented with quantum chemical calculations. The
model system is the reaction of a series of secondary alicyclic
amines toward phenyl 2,4,6-trinitrophenyl ether in aqueous
ethanol mixtures of different compositions. From solvent effect
studies, it is found that only piperidine is sensitive to solvation
effects, a result that may be traced to the polarity of the solvent
composition in the ethanol/water mixture, which points to a
specific electrophilic solvation in the aqueous phase.