Sponge-like ionic liquids for developing green chemical processes
The development of selective chemical transformations, combined with clean and straightforward separation technical approaches able for providing pure products, is the cornerstone to build green chemical industries. Although the combination of biocatalysts with ionic liquids (ILs) resulted in synergic platforms for synthetic processes, the development of easy, cheap and/or sustainable approaches for pure product extraction is key. Hydrophobic ILs based on cations with long alkyl side-chains are temperature switchable ionic liquid/solid phases that behave as sponge-like systems (Sponge-Like Ionic Liquids, SLILs). These SLILs permits the separation of nearly pure products by using centrifugation/filtration approaches on the solid system obtained after cooling. The SLILs reaction/separation systems can be shown as a new sustainable platform for preparation of pure chemicals.
ENZYMES AND IONIC LIQUIDS: A SYNERGIC COMBINATION
The sustainability of chemical processes begins with catalysis, because the selectivity in chemical transformations is directly related with several of the principles of green chemistry, i.e. prevention, atomic economy, less hazardous synthesis, reduction of derivatives, etc (1). In this way, the inherent formation of wastes/contaminants and undesired by-products in classical synthetic processes, which are based on the use of stoichiometric amounts of reagents, can be minimized by using catalytic steps (2). The important role of catalysts in chemical transformations is emphasized for the case of enzymes. They are the catalysts of living systems, and clearly constitute a powerful green tool-box for chemical processes, because of their far-ranging level in activity and selectivity (stereo-, chemo- and regioselectivity) for chemical reactions, as it is demonstrated for all the chemical transformation inside cells. In the same context, the technological applications of enzymes are greatly enhanced in non-aqueous environments, rather than in their natural aqueous reaction media, because of both the high solubi ...