Syntheses of fluorous quaternary ammonium salts and their application as phase transfer catalysts for halide substitution reactions in extremely nonpolar fluorous solvents Academic Article uri icon


  • Perfluoromethyldecalin solutions of the fluorous alkyl halides Rf8(CH2)mX (m=2, 3; X=Cl, I) are inert toward aqueous NaCl, KI, KCN, and NaOAc. However, substitution occurs at 100 C in the presence of 10 mol % of the fluorous ammonium salts (Rf8(CH2)2)(Rf8(CH2)5)3N+ I- (1) or (Rf8(CH2)3)4N+ Br- (2) (10 mol %), which are fully or partially soluble in perfluoromethyldecalin under these conditions. Stoichiometric reactions of (a) 1 and Rf8(CH2)3Br, and (b) 2 and Rf8(CH2)2I are conducted in perfluoromethyldecalin at 100 C, and yield the same Rf8(CH2)mI/Rf8(CH2)mBr equilibrium ratio (60-65:40-35). This shows that ionic displacements can take place in extremely nonpolar fluorous phases, and suggests a classical phase transfer mechanism for the catalyzed reactions. Interestingly, the non-fluorous ammonium salt mixture CH3(CH3(CH2)m)3N+ Cl- (3, Aliquat 336; m=2:1 7/9) also catalyzes halide substitutions, but under triphasic conditions with 3 suspended between the lower fluorous and upper aqueous layers. NMR experiments establish very low solubilities in both phases, suggesting interfacial catalysis. 2009 Elsevier Ltd. All rights reserved.

published proceedings


author list (cited authors)

  • Mandal, D., & Gladysz, J. A.

citation count

  • 8

complete list of authors

  • Mandal, Debaprasad||Gladysz, John A

publication date

  • January 2010