Impact of amines as co-modifiers on the enantioseparation of various amino acid derivatives on a tert-butyl carbamoylated quinine-based chiral stationary phase

Resolution of Racemates and Enantioselective Analytics by Cinchona Alkaloids and Their Derivatives

“…The 16 proteinogenous racemic amino acids as various N-protected derivatives (Table 13.2) have been baseline separated using cinchona 9-O-carbamate type CSPs under polar organic or reversed phase conditions. Many synthetically important protecting groups, such as Ac, Fmoc, Bz, Z are tolerated in the process of chromatography; however, employment of the p-acidic 3,5-dinitrobenzoyl group (DNB) gave extraordinary high enantioselectivities (a > 10) [44,60,[63][64][65][66][67][68]. Selected examples of enantioseparation of N-protected amino acids are provided in Table 13.2.…”

Recent advances in the direct and indirect liquid chromatographic enantioseparation of amino acids and related compounds: A review

“…A t-butyl carbamoylated quinine-based CSP for direct enantiomer separation of various natural and unnatural amino acid derivatives was studied by Xiong et al [91] ( Table 2). The influence of functional groups in the amino acid side chains upon the enantioseparation is discussed.…”

Immobilized-type chiral packing materials for HPLC based on polysaccharide derivatives

“…Recently, the cinchona alkaloid-based CPMs developed by Lindner et al have been commercialized under the trade names Chiralpak QN-AX and Chiralpak QD-AX, which are prepared from the 9O-tert-butylcarbamate derivatives of quinine and quinidine as chiral selectors, respectively [30,31]. These CPMs show excellent chiral recognitions for a wide range of chiral acids including important intermediates in pharmaceuticals and efficient chiral auxiliaries and ligands for asymmetric synthesis [34][35][36][37][38].…”