Abstract

Background: Over the past decade, catalysis by ionic liquids (ILs), has gained much attention, due to its variety in catalytic reactions that have been successfully carried out in such clean media for green chemistry, especially in synthetic and catalytic transformations. Catalysis in ILs is one of the most promising greener reactions in catalytic science. ILs, have several advantages, that they are used as alternative solvents in the progress of catalytic reactions as compared to traditional volatile organic solvents. ILs have one of the most important advantages that they have lower vapor pressure which is favorable for developing greener catalytic technologies. For this particular cause (low volatility) ILs are called as green solvents.

Methods: Recently, the development of chiral ionic liquids and their applications in asymmetric synthesis has attracted much attention as these reactions have widespread applications in the synthesis of chiral drugs and pharmaceutical industries.

Results: Asymmetric induction is mainly achieved by the use of chiral substrates or reagents, chiral catalysts or enzymes. There are also numbers of structurally modified ILs that have been synthesized at room temperature. This review focuses on imidazolium ionic liquids that possess chirality either in imidazolium or in anion moiety.

Conclusions: The aim of this review is to highlight the recent breakthrough of Chiral ILs in chirality transfer or chiral recognition when used as solvent or co-solvent: the case of task specific ionic liquids is beyond the scope of this review. In the first part, the synthesis of CILs will be presented while the second part will be devoted to their use in the field of asymmetric synthesis as well as various pharmaceutical industries.

Keywords: Chiral ionic liquids, synthesis & applications, green synthesis.

Graphical Abstract