Ligand-exchange chromatographic separation of DL-amino acids on aminopropylsilica-bonded chirals-triazines

Abstract

SummaryChiral stationary phases (CSPs) were synthesized by reaction of aminopropylsilica (APS) with chiral monochloro-s-triazines (MCTs). MCTs were obtained by reaction of 2,4,6-trichloro-s-triazine (cyanuric chloride) with one equivalent of methanol and, subsequently, with one equivalent of L-proline tert butyl ester (HPro-OtBu) or N-ten butyloxycarbonyl-L-lysine tert butyl ester (Boc-Lys-OtBu). End-capping of unreacted amino groups of APS with acetic anhydride, followed by trifluoroacetolytic cleavage of the protecting groups of amino acids (AAs), afforded two chiral stationary phases bearing either L-proline (CSP-3) or L-lysine (CSP-4) as chiral selector. Using ligand-exchange chromatography with addition of Cu 2+ to the mobile phase, enantiomers of free DL-AAs and a few N-(2,4-dinitrophenyl)-DL-AAs were separated on CSP-3, whereas N-(dansyl)-DL-AAs were separated on CSP-4.

Chiral separation by chromatographic and electromigration techniques. A Review

“…u uckner [242] reported the synthesis of a new CLEC phase by binding lproline or l-lysine to aminopropylsilanized silica through a triazine spacer. While the first phase was found to be suitable to resolve underivatized amino acids and N-(2,4-dinitrophenyl) amino acids, the second phase resolved Dns-amino acids.…”

Synthesis and Application of C2 and C3 Symmetric (R)‐Phenylglycinol‐Derived Chiral Stationary Phases

“…Various types of high‐performance liquid chromatography (HPLC) chiral stationary phases (CSPs) such as brush/Pirkle‐type stationary phases, crown ethers, ligand exchange, proteins, polysaccharides, cyclodextrin, and cyclofructan have been developed . Many amino acid‐based CSPs have been reported as chiral selectors; for example, (S)‐leucine and (R)‐phenylglycine‐derived brush/Pirkle‐type CSP, (S)‐proline‐ and (S)‐lysine‐derived ligand‐exchange CSPs, and a protein CSP . Various aminoalcohol‐derived CSPs have also been synthesized using (R)‐phenylglycinol, (S)‐alaninol, (S)‐leucinol, and (S)‐tert‐leucinol.…”

Evaluation of fluorescent monochloro-s-triazine reagent for amino acid analysis

“…This approach has been extended to the synthesis of silica-bonded, chiral stationary phases resulting from the reaction of cyanuric chloride with pyrrolidine and L-alanine [13], amino acid esters [14], amino acid amides [15], chiral aromatic amines [16], peptide esters [17,18], or bovine serum albumin [19]. Although most of the work on the use of s-triazines in chromatography focused on the synthesis of chiral stationary phases or chiral derivatizing reagents, syntheses of a few nonchiral reagents based on cyanuric chloride have also been described.…”