Chiral separation by enantioselective liquid–liquid extraction

Abstract

The literature on enantioselective liquid-liquid extraction (ELLE) spans more than half a century of research. Nonetheless, a comprehensive overview has not appeared during the past few decades. Enantioselective liquid-liquid extraction is a technology of interest for a wide range of chemists and chemical engineers in the fields of fine chemicals, pharmaceuticals, agrochemicals, fragrances and foods. In this review the principles and advances of resolution through enantioselective liquid-liquid extraction are discussed, starting with an introduction on the principles of enantioselective liquid-liquid extraction including host-guest chemistry, extraction and phase transfer mechanisms, and multistage liquid-liquid extraction processing. Then the literature on enantioselective liquid-liquid extraction systems is reviewed, structured on extractant classes. The following extractant classes are considered: crown ether based extractants, metal complexes and metalloids, extractants based on tartrates, and a final section with all other types of chiral extractants.

Horizontal reactive distillation for multicomponent chiral resolution

“…A number of separation methods have been developed to isolate a desired active ingredient enantiomer; however, these methods generally are effective only for systems having the required phase behavior, or they may require development of a specific resolving agent such as a specialty extractant, specialized chromatography/adsorption media, or a custom-made membrane. Examples include crystallization, 4 chromatography, [5][6][7][8] liquid-liquid extraction, 9,10 and membrane-based separation methods. 11 Another route to a chiral active ingredient involves production of small molecule chiral synthons (synthetic building blocks) for use as reagents in a subsequent asymmetric (chiral) synthesis.…”

Studies on multistage enantioselective liquid–liquid extraction of amino-(4-nitro-phenyl)-acetic acid enantiomers using CuPF6{(S)-BINAP}: Experiments and modeling

“…So, it is necessary to gain new more efficient chiral separation methods. Enantioselective liquid-liquid extraction (ELLE) provides an attractive alternative to fulfill the need, which is expected to be cheaper and easier to scale up to commercial scale and has a wide range of application [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”

A mild and efficient one-pot three-component synthesis of anti-β-amino-carbonyl compounds catalyzed by NH4OAc and their anticancer activities

“…About 56 % of the drugs are chiral compounds, and about 88 % of these chiral synthetic drugs are used therapeutically as racemates (Rentsch, 2002;Leffingwell, 2003). Enantiomers can be prepared either via a synthetic approach or by the separation of racemates (Noyori, 1994;Schuur et al, 2011). Enantiomerically pure compounds can be obtained through the synthetic routes using either natural compounds or asymmetric synthesis.…”