Room-Temperature Ionic Liquids. Solvents for Synthesis and Catalysis

Lipase-catalyzed reactions in ionic liquids

[reaction:see text] Candida antarctica lipase was shown to catalyze alcoholysis, ammoniolysis, and perhydrolysis reactions using the ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate or hexafluorophosphate as reaction media. Reaction rates were generally comparable with, or better than, those observed in organic media.

Ionic Liquids-New "Solutions" for Transition Metal Catalysis

Ionic liquids are salts that are liquid at low temperature (<100 degrees C) which represent a new class of solvents with nonmolecular, ionic character. Even though the first representative has been known since 1914, ionic liquids have only been investigated as solvents for transition metal catalysis in the past ten years. Publications to date show that replacing an organic solvent by an ionic liquid can lead to remarkable improvements in well-known processes. Ionic liquids form biphasic systems with many organic product mixtures. This gives rise to the possibility of a multiphase reaction procedure with easy isolation and recovery of homogeneous catalysts. In addition, ionic liquids have practically no vapor pressure which facilitates product separation by distillation. There are also indications that switching from a normal organic solvent to an ionic liquid can lead to novel and unusual chemical reactivity. This opens up a wide field for future investigations into this new class of solvents in catalytic applications.

Palladium-catalyzed synthesis of aqueous, fluorous, and supercritical CO2-soluble phosphines

[reaction: see text]A generic, simple, and economical route has been developed for the synthesis of phosphines soluble in aqueous, fluorous, and supercritical CO2 phases. The methodology is based on the palladium-catalyzed Heck olefination of haloarylphosphine oxides followed by reduction, affording various arylphosphines in high yields.