Abstract
Given the importance of chirality in the biological response, regulators, industries and researchers require chiral compounds in their enantiomeric pure form. Therefore, the approach to separate enantiomers in preparative scale needs to be fast, easy to operate, low cost and allow obtaining the enantiomers at high level of optical purity. A variety of methodologies to separate enantiomers in preparative scale is described, but most of them are expensive or with restricted applicability. However, the use of membranes have been pointed out as a promising methodology for scale-up enantiomeric separation due to the low energy consumption, continuous operability, variety of materials and supports, simplicity, eco-friendly and the possibility to be integrated into other separation processes. Different types of membranes (solid and liquid) have been developed and may provide applicability in multi-milligram and industrial scales. In this brief overview, the different types and chemical nature of membranes are described, showing their advantages and drawbacks. Recent applications of enantiomeric separations of pharmaceuticals, amines and amino acids were reported.
Highlights
Chiral separation is an essential undertaking throughout discovery and development of biological active substances, with enantiomeric forms often possessing different biological effects [1,2]
There are a wide variety of methods to achieve enantiomerically pure compounds through the “racemic approach” including preparative liquid chromatography (LC) [7,8] and supercritical fluid chromatography (SFC) [9,10,11] with chiral stationary phases (CSPs), asymmetric catalysis [12], diastereomeric crystallization [13,14], dynamic kinetic resolution [15], simulated moving bed [16,17,18], enzyme-mediated kinetic resolution [19,20], molecular imprinting technology [21], optical force [22], methods based on liquid−liquid partitioning such as liquid−liquid extraction (LLE), and membranes [23]
The use of chiral membranes demonstrates to be a promising approach for scaling up enantiomeric separations, and a variety of new materials is under investigation, including chiral inorganic structures
Summary
Chiral separation is an essential undertaking throughout discovery and development of biological active substances, with enantiomeric forms often possessing different biological effects [1,2]. Considering that, all stereoisomers are required for biological screening, in both racemic mixture and enantiomerically pure form In this sense, the “racemic approach” achieves products by a reaction sequence that, generally, presents a much lower degree of difficulty and cost than the reaction involved in “chiral approach”. There are a wide variety of methods to achieve enantiomerically pure compounds through the “racemic approach” including preparative liquid chromatography (LC) [7,8] and supercritical fluid chromatography (SFC) [9,10,11] with chiral stationary phases (CSPs), asymmetric catalysis [12], diastereomeric crystallization [13,14], dynamic kinetic resolution [15], simulated moving bed [16,17,18], enzyme-mediated kinetic resolution [19,20], molecular imprinting technology [21], optical force [22], methods based on liquid−liquid partitioning such as liquid−liquid extraction (LLE), and membranes [23]. More research in membranes development and applications are required
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
