Editorial [Hot Topic: Ionic Liquid Applications in the Synthesis of Organic Building Blocks (Guest Editor: Sanjay V. Malhotra)]

Ionic liquids have advanced from the curiosity of ‘novel materials’ [1] of 1980s, ‘green solvents’ [2] of 1990s to the ‘designer chemicals’ [3] of the 21st century. This has been possible to a large extent due to realization that their physiochemical properties can be ‘tuned’ by judicious pairing of cations and anions. Of course, this feature has attracted scientists from various disciplines leading to phenomenal growth in our understanding of these materials. The scientific potential for research in ionic liquids is unlimited. Beyond the growing library of structures, the diversity of interdisciplinary research has helped in expanding the catalog of their applications. This is evident from the fact that Ionic liquids find wide ranging applications spanning for example, electrochemistry [4], synthesis [5], biochemistry [6], materials science [7, 8], pharmaceuticals and therapeutics [9]. Given the perceived toxicity issues, their utility as potential ‘therapeutics’ [10, 11] is very encouraging and promises unforeseen applications in the field of biomedical sciences. Among numerous advantages, the potential to manipulate their solvent properties has certainly helped in overcoming some of the challenges seen with conventional organic solvents in the synthesis of natural building blocks such as the carbohydrates, nucleosides, heterocycles etc. These achievements are highlighted in five review articles selected for this special issue of the Current Organic Synthesis. Topics covered include the utility of chloroferrate ILs as solvents and catalysts with a particular focus on reactions leading to pharmaceutically active compounds and intermediates (Bica et al.) The advantages using ionic liquids in the dissolution and transformation of carbohydrates are covered by Rosatella et al. Nucleosides derived molecules are biologically importantand found as active drugs. The effectiveness of ionic liquids in nucleoside chemistry is summarized by Kumar et al. Similarly, N-heterocyclic compounds are major building blocks for natural products with biological activity. The focus of article by Yadav et al. is on the advances made in the synthesis of these compounds using ionic liquids. Finally, the review by Pedro et al. highlights the synergistic applications of ILs with scCO2 in bio-catalytic systems allowing multistep organic synthesis in continuous flow processes.