Chromatographic enantiomer separation using 9-amino-9-(deoxy)-epiquinine-derived chiral selectors: control of chiral recognition via introduction of additional stereogenic centers was written by Maier, Norbert M.;Greco, Elisa;Petrovaj, Jan;Lindner, Wolfgang. And the article was included in Acta Chimica Slovenica in 2012.Category: piperidines The following contents are mentioned in the article:
Three new cinchona-type chiral selectors were prepared by attaching N-pivaloyl-glycine, N-pivaloyl-(S)-valine and N-pivaloyl-(R)-valine segments to the C9-amino function of 9-amino-9-(deoxy)-epiquinine (eAQN), and immobilized to silica to provide the corresponding chiral stationary phases (CSPs). Evaluation of the chromatog. enantioseparation characteristics of these CSPs with a broad assortment of N-carbamoyl protected amino acids under polar organic mobile phase conditions revealed modest chiral recognition capabilities for N-Fmoc-, N-Cbz- and N-Boc-derivatives The enantioselective analyte binding to these CSPs is strictly controlled by the absolute stereochem. of the amino acid functionalities attached to the C9-amino group of the eAQN framework. Specifically, the CSP derived from (S)-valine-based selector exhibits preferential binding of N-carbamoyl-(S)-amino acids, while the CSPs featuring (R)-valine- and the glycine-derived selectors show opposite enantioselective binding preference. The observed impact of analyte structure on enantioselectivity and the specific preferences in enantioselective binding point to chiral recognition mechanisms capitalizing on intermol. ion pairing, hydrogen bonding and subtle steric interactions, with the latter making the crucial contributions to stereodiscrimination. The finding that the chiral recognition characteristics of epiquinine can be readily controlled via incorporation of addnl. stereogenic centers remote from the cinchona scaffold might be useful information for the design of new enantioselective receptors and organocatalysts. This study involved multiple reactions and reactants, such as (S)-1-(((9H-Fluoren-9-yl)methoxy)carbonyl)piperidine-2-carboxylic acid (cas: 86069-86-5Category: piperidines).
(S)-1-(((9H-Fluoren-9-yl)methoxy)carbonyl)piperidine-2-carboxylic acid (cas: 86069-86-5) belongs to piperidine derivatives. The piperidine structural motif is present in numerous natural alkaloids. These include piperine, which gives black pepper its spicy taste. Piperidine prefers a chair conformation, similar to cyclohexane. Unlike cyclohexane, piperidine has two distinguishable chair conformations: one with the N–H bond in an axial position, and the other in an equatorial position.Category: piperidines
Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem