Direct high-performance liquid chromatographic enantioseparation of secondary amino acids on Cinchona alkaloid-based chiral zwitterionic stationary phases. Unusual temperature behavior was written by Ilisz, Istvan;Gecse, Zsanett;Pataj, Zoltan;Fulop, Ferenc;Toth, Geza;Lindner, Wolfgang;Peter, Antal. And the article was included in Journal of Chromatography A in 2014.Reference of 151004-92-1 This article mentions the following:
Two chiral stationary phases containing a quinine- or a quinidine-based zwitterionic ion-exchanger as chiral selector were applied for the enantioseparation of 27 unusual cyclic secondary α-amino acids. The effects of the nature and concentration of the bulk solvent, the acid and base additives, the structures of the analytes and temperature on the enantioresoln. were studied. To study the effects of temperature and to obtain thermodn. parameters, experiments were carried out at constant mobile phase compositions in the temperature range -5 to 55°. The thermodn. parameters indicated that in most cases the separations were enthalpy-driven, but some entropy-driven separations were also observed The sequence of elution of the enantiomers was determined in most cases. In the experiment, the researchers used many compounds, for example, (S)-1,2,3,4-Tetrahydroisoquinoline-1-carboxylic acid (cas: 151004-92-1Reference of 151004-92-1).
(S)-1,2,3,4-Tetrahydroisoquinoline-1-carboxylic acid (cas: 151004-92-1) belongs to tetrahydroisoquinoline derivatives. Tetrahydroisoquinoline, as a secondary amine, tetrahydroisoquinoline has weakly basic properties and forms salts with strong acids. An oxidative C1 arylation of tetrahydroisoquinolines with aryl Grignard reagents is mediated by diethyl azodicarboxylate (DEAD). This C-H activation under metal-free conditions delivers target compounds, including some naturally occurring alkaloids, in good yields.Reference of 151004-92-1
Referemce:
Tetrahydroisoquinoline – Wikipedia,
1,2,3,4-Tetrahydroisoquinoline | C9H11N – PubChem