2.5. Stabilization of IL Emulsions by Nanoparticles 2623 3. Hydrogenations in ILs 2623 3.1. Hydrogenation on IL-Stabilized Nanoparticles 2623 3.1.1. Hydrogenation of 1,3-Butadiene 2623 3.1.2. Hydrogenation of Alkenes and Arenes 2624 3.1.3. Hydrogenation of Ketones 2624 3.2. Homogeneous Catalytic Hydrogenation in ILs 2624 3.3. Hydrogenation of Functionalized ILs 2625 3.3.1. Selective Hydrogenation of Polymers 2625 3.4. Asymmetric Hydrogenations 2626 3.4.1. Enantioselective Hydrogenation 2626 3.5. Role of the ILs Purity in Hydrogenation Reactions 2628

Catalysis in ionic liquids

Ionic liquids are remarkable chemical compounds, which find applications in many areas of modern science. Because of their highly tunable nature and exceptional properties, ionic liquids have become essential players in the fields of synthesis and catalysis, extraction, electrochemistry, analytics, biotechnology, etc. Apart from physical and chemical features of ionic liquids, their high biological activity has been attracting significant attention from biochemists, ecologists, and medical scientists. This Review is dedicated to biological activities of ionic liquids, with a special emphasis on their potential employment in pharmaceutics and medicine. The accumulated data on the biological activity of ionic liquids, including their antimicrobial and cytotoxic properties, are discussed in view of possible applications in drug synthesis and drug delivery systems. Dedicated attention is given to a novel active pharmaceutical ingredient-ionic liquid (API-IL) concept, which suggests using traditional drugs in ...

Biological Activity of Ionic Liquids and Their Application in Pharmaceutics and Medicine.

Chemical and biochemical transformations in ionic liquids

Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition.

Acidic Ionic Liquids.

The lipase from Thermomyces laguginosus (formerly Humicola laguginosa) (TLL) is a basophilic and noticeably thermostable enzyme, commercially available in both soluble and immobilized form. Although initially oriented toward the food industry, the enzyme has found applications in many different industrial areas, from biodiesel production to fine chemicals (mainly in enantio and regioselective or specific processes). This review intends to show some of the most relevant aspects of the use of this interesting enzyme. After checking the enzyme features, some of the most efficient methods of TLL immobilization will be commented. Finally, the main uses of the enzyme will be revised, with special emphasis in the modification of fats and oils, production of biodiesel, resolution of racemic mixtures, enantioselective hydrolysis of prochiral esters and regioselective process involving sugar preparations. In many instances, TLL has been compared to other lipases, the advantages or disadvantages of the enzyme will be discussed.

Lipase from Thermomyces lanuginosus: Uses and prospects as an industrial biocatalyst

The Ferrier glucosylation of alcohols with 3,4,6-tri- O-acetyl-d-glucal has been investigated with several metal nitrates and the optimal catalyst is bismuth nitrate pentahydrate (BNP). Good yields of pseudoglycals were also obtained with ferric nitrate nonahydrate (FNN), heightening the catalyst dosage (50 mol%) being required however. The BNP-mediated reactions showed remarkable solvent dependency and in the optimal protocol, the amount of BNP as low as 10 mol% was effective, furnishing excellent yields of O-glucosides with good anomeric selectivity in acetonitrile. A comparison of BNP and FNN in terms of yields and selectivity of the product has been made. In comparison to the reactions in acetonitrile, the catalytic ability of BNP was found to enhance drastically in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF 6]. © 2005 Elsevier B.V. All rights reserved.

Metal nitrates catalysed O-glucosylation using acetyl glucal in organic solvents and ionic liquids: A comparative investigation

Lipase-mediated regioselective biotransformations such as hydrolysis and alcoholysis of 3,4,6-tri- O -acetyl- d -glucal, 1 have been studied in organic solvent, tetrahydrofuran (THF) and two different ionic liquids, namely 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim]PF 6 and 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim]BF 4 . The influence of different reaction media on the rates and regioselectivity of enzyme catalysis has been demonstrated. A marked regioselectivity towards the formation of 4,6-di- O -acetyl- d -glucal, 2 was observed in [bmim]PF 6 with 84% product formation after 6 h with 98% selectivity in hydrolysis and 48% after 8 h with 98% selectivity in alcoholysis.

Influence of ionic liquids on the rates and regioselectivity of lipase-mediated biotransformations on 3,4,6-tri-O-acetyl-d-glucal

A hydroxyl group appended task specific ionic liquid was designed and synthesised. The ionic liquid was used as a vehicle for the substrate of our interest for lipase catalysed kinetic resolution. The ionic liquid anchored ibuprofen underwent Candida antarctica lipase catalysed hydrolysis yielding the S-enantiomer. The strategy facilitated easy post-resolution isolation of the enantiomers and also carries the prospect of recyclability.

Prashant U. Naik

Papers

Metal nitrates catalysed O-glucosylation using acetyl glucal in organic solvents and ionic liquids: A comparative investigation

Influence of ionic liquids on the rates and regioselectivity of lipase-mediated biotransformations on 3,4,6-tri-O-acetyl-d-glucal

Ionic liquid anchored substrate for enzyme catalysed kinetic resolution

Enzyme Mediated Reactions in Ionic Liquids

Ionic liquid enabled sulfamoylation of arenes: an ambient, expeditious and regioselective protocol for aryl sulfonamides