1. Synthesis and chromatographic evaluation of new polymeric chiral stationary phases based on three (1s,2s)-(-)-1,2-diphenylethylenediamine derivatives in hplc and sfc.
Eranda Wanigasekara, Tharanga Payagala, Daniel W Armstrong. Anal Bioanal Chem. 2011 Mar; 399(7): 2445-61. DOI: 10.1007/s00216-010-4615-6. PMID: 21203750.
Three new polymeric chiral stationary phases were synthesized based on (1S,2S)-1,2-bis(2,4,6-trimethylphenyl)ethylenediamine, (1S,2S)-1,2-bis(2-chlorophenyl)ethylenediamine, and (1S,2S)-1,2-di-1-naphthylethylenediamine via a simple free-radical-initiated polymerization in solution. These monomers are structurally related to (1S,2S)-1,2-diphenylethylenediamine which is the chiral monomer used for the commercial P-CAP-DP polymeric chiral stationary phase (CSP). The performance of these three new chiral stationary phases were evaluated in normal phase high-performance liquid chromatography (HPLC) and supercritical fluid chromatography and the results were compared with those of the P-CAP-DP column. All three new phases showed enantioselectivity for a large number of racemates with a variety of functional groups, including amines, amides, alcohols, amino acids, esters, imines, thiols, and sulfoxides. In normal phase, 68 compounds were separated with 28 baseline separations (Rs ≥ 1.5) and in SFC, 65 compounds were separated with 24 baseline separations. In total 72 out of 100 racemates were separated by these CSPs with 37 baseline separations. Complimentary separation capabilities were observed for many analytes. The new polymeric CSPs showed similar or better enantioselectivities compared with the commercial column in both HPLC and SFC. However, faster separations were achieved on the new stationary phases. Also, it was shown that these polymeric stationary phases have good sample loading capacities while maintaining enantioselectivity.
2. Tuning mechanism in a two-component columnar host system composed of 1,2-diphenylethylenediamine and 1,1'-binaphthyl-2,2'-dicarboxylic acid.
Kakuhiro Kawaguchi, Tomohiro Sato, Yoshitane Imai, Yoshio Matsubara, Katuzo Murata, Reiko Kuroda. Org Lett. 2008 Feb 7; 10(3): 469-71. DOI: 10.1021/ol7028433. PMID: 18183998.
In a two-component columnar host system composed of racemic (rac)-1,2-diphenylethylenediamine and rac-1,1'-binaphthyl-2,2'-dicarboxylic acid, a cavity tuning mechanism resulted from changes in the structure of the columns using a specific combination of the following four molecules: (1R,2R)-1, (1S,2S)-1, (R)-2, and (S)-2.
