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

摘要: Abstract Perfluoromethyldecalin solutions of the fluorous alkyl halides R f 8 (CH 2 ) m X ( =2, 3; X=Cl, I) are inert toward aqueous NaCl, KI, KCN, and NaOAc. However, substitution occurs at 100 °C in presence 10 mol % ammonium salts )(R 5 3 N + I − 1 or 4 Br (10 mol %), which fully partially soluble perfluoromethyldecalin under these conditions. Stoichiometric reactions (a) Br, (b) conducted 100 °C, yield same I/ equilibrium ratio (60–65:40–35). This shows that ionic displacements can take place extremely nonpolar phases, suggests a classical phase transfer mechanism for catalyzed reactions. Interestingly, non-fluorous salt mixture CH Cl , Aliquat ® 336; =2:1 7/9) also catalyzes halide substitutions, but triphasic conditions with suspended between lower upper layers. NMR experiments establish very low solubilities both suggesting interfacial catalysis.