7006-34-0Relevant articles and documents
Noncovalently Functionalized Commodity Polymers as Tailor-Made Additives for Stereoselective Crystallization
Wan, Xinhua,Wang, Zhaoxu,Ye, Xichong,Zhang, Jie
supporting information, p. 20243 - 20248 (2021/08/09)
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.
A method of synthesizing L - asparagine (by machine translation)
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Page/Page column 4-6, (2019/05/08)
The invention provides a method of synthesizing L - asparagine, the main technical means is to L - aspartic acid as the raw material, first to the reaction in the cauldron the pump enters methanol, then open the reaction kettle, input L - aspartic acid, cooling, subsequently drop adds the chlorination sulfoxide, generating L - aspartic acid methyl ester hydrochloride, then will be of the L - aspartic acid methyl ester hydrochloride into a reaction kettle, then to the reaction in the cauldron the pump enters the ammonia, to obtain the L - asparagine, the method generating L - aspartic acid methyl ester hydrochloride intermediate product, the intermediate product is stable structure, safe and non-toxic, for subsequent operation processing, reaction process only needs to have the participation of ammonia water, reactant complex, the small influence of the product, the method of the invention recovery of the methanol up to 99.5 - 99.9%, not only improving the intermediate the purity of the product, and also avoids the pollution of methanol, L - asparagine is finished effective content of 80 - 85%, moisture content is 15 - 18%, yield and moisture content are higher than the amount of the existing products, the method of the invention is suitable for industrial production. (by machine translation)
Self-Reporting Inhibitors: A Single Crystallization Process To Obtain Two Optically Pure Enantiomers
Ye, Xichong,Cui, Jiaxi,Li, Bowen,Li, Na,Zhang, Jie,Wan, Xinhua
, p. 8120 - 8124 (2018/06/29)
Collection of two optically pure enantiomers in a single crystallization process can significantly increase the chiral separation efficiency but this is difficult to realize. Now a self-reporting strategy is presented for visualizing the crystallization process by a dyed self-assembled inhibitor made from the copolymers with tri(ethylene glycol)-grafting polymethylsiloxane as the main chain and poly(N6-methacryloyl-l-lysine) as side chains. When applied with seeds together for the fractional crystallization of conglomerates, the inhibitors can label the formation of the secondary crystals and guide the complete separation process of two enantiomers with colorless crystals as the first product and red crystals as the second. This method leads to high optical purity of d/l-Asn?H2O (99.9 % ee for d-crystals and 99.5 % for l-crystals) in a single crystallization process. It requires a small amount of additives and shows excellent recyclability.
