A Protic Ionic Liquid, when Entrapped in Cationic Reverse Micelles, can be Used as Suitable Solvent for a Bimolecular Nucleophilic Substitution Reaction

CROSIO, M.; CORREA N.M.; SILBER J.J.; FALCONE R.D.

ORGANIC & BIOMOLECULAR CHEMISTRY

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2016 vol. 14 p. 3170 - 3177

1477-0520

In this work, we have explored how the confinement of the protic ionic liquid (IL) ethylammonium nitrate(EAN) inside toluene/benzyl-n-hexadecyldimethylammonium chloride (BHDC) reverse micelles (RMs)affects the Cl− nucleophilicity on the bimolecular nucleophilic substitution (SN2) reaction between thisanion and dimethyl-4-nitrophenylsulfonium trifluoromethanesulfonate. To the best of our knowledge thisis the first report where toluene/BHDC RMs use EAN as a polar component and it is used as a nanoreactorfor carrying out kinetic experiments. Dynamic light scattering results reveal the formation of RMs containingthe protic IL. The kinetic results show that upon confinement, EAN becomes a suitable solvent for theSN2 reaction while in homogeneous media it is a bad option. Entrapped in BHDC RMs, due to the stronghydrogen bond interactions, EAN behaves as an aprotic-like IL which cannot deactivate the nucleophilicpower of Cl− and yet increases the substrate solubility. These facts show the versatility of this kind oforganized system to alter the polar solvent entrapped and its influence on the reaction rate when it isused as a nanoreactor.