5928-67-6Relevant articles and documents
C3 The symmetry contains a chiral ligand H3L of an amide bond. Preparation method and application
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Paragraph 0092-0100, (2021/09/08)
The invention discloses C. 3 Chiral ligand H with symmetric amide bond3 L Relates to the technical field of material chemistry and chiral chemistry. The invention further provides the chiral ligand H. 3 L Preparation method and application thereof. The present invention has the advantage that the chiral ligand H of the present invention is a chiral ligand. 3 The L has a higher C. 3 The symmetric and flexible amide group enables coordination of the lanthanide metal ions with high coordination number and high oxygen affinity to be assembled into a novel structure-structure lanthanide metal chiral porous coordination cage. Moreover, the abundant chiral amide groups and amino acid residues on the ligand framework can be directly introduced into the synthesized lanthanide metal chiral porous coordination cage, thereby being beneficial to generating multiple chiral recognition sites and unique chiral microenvironments which mimic the biological enzyme binding pocket and further realize the purpose of high enantioselectivity separation of a series of chiral small molecule compounds.
Microbial synthesis of (S)- And (R)-benzoin in enantioselective desymmetrization and deracemization catalyzed by aureobasidium pullulans included in the blossom protect agent
Ko?odziejska, Renata,Studzinska, Renata,Tafelska-Kaczmarek, Agnieszka,Pawluk, Hanna,Mlicka, Dominika,Wozniak, Alina
, (2021/05/07)
In this study, we examined the Aureobasidium pullulans strains DSM 14940 and DSM 14941 included in the Blossom Protect agent to be used in the bioreduction reaction of a symmetrical dicarbonyl compound. Both chiral 2-hydroxy-1,2-diphenylethanone antipodes were obtained with a high enantiomeric purity. Mild conditions (phosphate buffer [pH 7.0, 7.2], 30 ?C) were successfully employed in the synthesis of (S)-benzoin using two different methodologies: benzyl desymmetrization and rac-benzoin deracemization. Bioreduction carried out with higher reagent concentrations, lower pH values and prolonged reaction time, and in the presence of additives, enabled enrichment of the reaction mixture with (R)-benzoin. The described procedure is a potentially useful tool in the synthesis of chiral building blocks with a defined configuration in a simple and economical process with a lower environmental impact, enabling one-pot biotransformation.
Enantioselective N-heterocyclic carbene-catalysed intermolecular crossed benzoin condensations: Improved catalyst design and the role of in situ racemisation
Delany, Eoghan G.,Connon, Stephen J.
supporting information, p. 248 - 258 (2021/01/14)
The enantioselective intermolecular crossed-benzoin condensation mediated by novel chiral N-heterocyclic carbenes derived from pyroglutamic acid has been investigated. A small library of chiral triazolium ions were synthesised. Each possessed a tertiary alcohol H-bond donor and a variable N-aryl substituent. It was found that increasing both the steric requirement and the electron-withdrawing characteristics of the N-aryl ring led to more chemoselective, efficient and enantioselective chemistry, however both quenching the reaction at different times and deuterium incorporation experiments involving the product revealed that this is complicated by product racemisation in situ (except in the case of benzoin itself), which explains the dependence of enantioselectivity on the electrophilicity of the reacting aldehydes common in the literature. Subsequent protocol optimisation, where one reacting partner was an o-substituted benzaldehyde, allowed a range of crossed-benzoins to be synthesised in moderate-good yields with moderate to excellent enantioselectivity.
