Noncovalently Functionalized Commodity Polymers as Tailor‐Made Additives for Stereoselective Crystallization

Abstract

Stereoselective inhibition of the nucleation and crystal growth of one enantiomer aided by "tailor-made" polymeric additives is an efficient method to obtain enantiopure compounds. However, the conventional preparation of polymeric additives from chiral monomers are laborious and limited in structures, which impedes their rapid optimization and applicability. Herein, we report a "plug-and-play" strategy to facilitate synthesis by using commercially available achiral polymers as the platform to attach various chiral small molecules as the recognition side-chains through non-covalent interactions. A library of supramolecular polymers made up of two vinyl polymers and six small molecules were applied with seeds in the selective crystallization of seven racemates in different solvents. They showed good to excellent stereoselectivity in yielding crystals with high enantiomeric purities in conglomerates and racemic compound forming systems. This convenient, low-cost modular synthesis strategy of polymeric additives will allow for high-efficient, economical resolution of various racemates on different scales.

Effect of pendant stereostructure on backbone conformation and enantioseparation ability of helical polyacetylene‐based chiral stationary phases

“…In Table 2, S-pR could enantioselectively separate 10 racemates (4-7, 11, and 13-17) out of 18 and exhibited baseline separation for methyl mandelate (11). This PA displayed the strongest chiral resolving power towards hydrobenzoin (4), aromatic cyclic alcohol 6-7, and amide derivatives 13-14 among other PAs in this work.…”

“…[3][4][5] Under the circumstances, various optical resolving techniques have significantly advanced in recent decades. [6][7][8][9][10][11][12][13][14] Among them, high-performance liquid chromatography (HPLC) equipped with chiral stationary phases (CSPs) has become the most popular and powerful one for both analytical and preparative separation, owing to the rapid development of high-efficient CSPs. 15,16 Polysaccharide (e.g., cellulose and amylose) derivatives are perhaps the most commonly used CSPs.…”

“…Hence, it is very important to obtain enantiomerically pure chiral compounds and develop effective characterization methods towards their optical purities, especially for pharmaceutical, agrochemical, food additive, and fragrance industries 3–5 . Under the circumstances, various optical resolving techniques have significantly advanced in recent decades 6–14 . Among them, high‐performance liquid chromatography (HPLC) equipped with chiral stationary phases (CSPs) has become the most popular and powerful one for both analytical and preparative separation, owing to the rapid development of high‐efficient CSPs 15,16 .…”

Visualization of enantioselective recognition and separation of chiral acids by aggregation‐induced emission chiral diamine

“…Although asymmetric synthesis has made a significant progress, [32,33] most of the commercially chiral compounds are still obtained by enantioseparation due to its advantages of easy operation, inexpensive, and high reliability for mass production. Now, several enantioseparation tactics were developed, for example, stereoselective crystallization, [34][35][36] enzyme controlled separation, [37] and enantiomer-selective-magnetization, [38] selective aggregation, [31] chromatography. [39][40][41] Undoubtedly, selective crystallization is one of the most inexpensive and convenient technique to realize mass production.…”

Studies on the stereochemical behaviors of a winding vine-shaped molecular wire of a bithiophene dimer with molecular asymmetry

“…It is therefore an interesting possibility for the design of a linear linkage of molecular asymmetric chirality leading to a suitable oligomer. [7][8][9][10][11][12][13][14][15] We have been investigating a new class of organic compounds, winding vine-shaped (hetero)biaryls, that show molecular asymmetry. [16][17][18] We also learned that the isomerization barrier of bithiophene shown in Fig.…”