... Volume: Page: ... 4,5 The “heavy fluorous” phosphonium salt, (R f8 (CH 2 ) 2 ) 3 (R f6 (CH 2 ) 2 )P + I - , promoted a nucleophilic aliphatic substitution in an aqueous/CF 3 C 6 F 5 biphase, but it was essential to use a perfluorinated solvent because of the high ...