Reactivity of trihexyl(tetradecyl)phosphonium chloride, a room-temperature phosphonium ionic liquid

Trihexyl(tetradecyl)phosphonium chloride 1, a room-temperature ionic liquid, readily undergoes deuterium isotope exchange reaction in deuterated solvents. Under basic conditions, ionic liquid I was reactive and 50% deuterium exchanged oil all four P-CH2 methylene groups in 9 h at ambient temperature, 30 min at 50 degrees C, or 12 min at 65 degrees C. In addition, ionic liquid I reacted with sodium salts of substituted benzoates apparently through the direct S-N(2) carboxylate alkylation to form esters 2 and the resulting esters further converted, via Wittig reaction, to finally afford aryl ketones 4. (C) 2007 Elsevier Ltd. All rights reserved.