Ch18 Amines(pdf) - KFUPM Open Courseware

Phase-Transfer CatalysisPhase-Transfer CatalysisQuaternary ammonium salts are phase-transfercatalysts. They are soluble in nonpolar solvents.Quaternary ammonium salts are phase-transfercatalysts. They are soluble in nonpolar solvents.H 3 CCH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 3+N CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 3Cl –CH 2 CH 3+N CH 2 CH 3Cl –CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 3CH 2 CH 3Methyltrioctylammonium chlorideBenzyltriethylammonium chlorideExampleThe S N 2 reaction of sodium cyanide with butylbromide occurs much faster when benzyl-triethylammonium chloride is present than whenit is not.(aqueous)CH 2 CH 3+NCH 2 CH 3CH 2 CH 3Cl –+CN –(aqueous)MechanismCH 3 CH 2 CH 2 CH 2 Br +NaCNbenzyltriethylammonium chlorideCH 3 CH 2 CH 2 CH 2 CN + NaBr