Elucidation of the mechanism of chiral selectivity in diastereomeric salt formation using organic solvent nanofiltration

Abstract

Organic solvent nanofiltration (OSN) was used to investigate the mechanism of chiral selectivity in diastereomeric salt formation of alpha-phenylethylamine with D-tartaric acid and di-p-toluoyl-D-tartaric acid as resolving agents; results indicate that for these systems chiral selectivity occurs only upon crystallisation and chiral interactions in solution were negligible.

Rational approach to the selection of conditions for diastereomeric resolution of chiral amines by diacid resolving agents

“…There is no chiral recognition in solution. 16 Therefore, the same value is assigned to equilibrium constants of reactions in the mother liquid independently of the enantiomer considered, that is,…”

“…16 Briefly, this data was obtained by nanofiltering different solutions comprising different molar ratios of diacid resolving agent and racemic PEA, at concentrations below the solubility limits of the diastereomeric salts. The molecular weight cut off of the membrane employed was selected in order to permeate only the unreacted amine, whilst the resolving agent diastereomeric salts were retained.…”

“…Rejection = (1 À Cp/ Cr) · 100, with Cp and Cr as the PPI2 concentrations on the permeate and retentate, respectively. Detailed experimental techniques can be found elsewhere 16. …”

An Exploration of Induced Supramolecular Chirality Through Association of Chiral Ammonium Ions and Tartrates with the Achiral Host Cucurbit[7]uril

“…The differences may indicate a pairing of ammonium tartrate salts under aqueous conditions even before the addition of Q [7]. [15] There are clear differences between the two racemic forms of both the Q [7]]/MBA + HT À sets and the Q [7]]/ABC + HT À ] sets. It was anticipated that these differences could indicate that separation may have a chance.…”

Designing organic solvent separation membranes: polymers, porous structures, 2D materials, and their combinations

“…Finally, we present the emerging 2D materials for this application. API or key intermediate purification [30][31][32][33][34][35][36][37][38] Tetracycline/ Mepenzolate/ Chlorhexidine from solvents Impurity removal 39,40 Genotoxic impurity removal Catalyst recovery [41][42][43] Pd(II)acetate from solvents Peptides separation 44 Peptides from solvents Stereoselective separation [45][46][47][48] (R)-1-phenylethanol over (S)-1-phenylethanol 350-1000 6-10 Å* BTEX separation 4,49 p-Xylene/ o-xylene 5.5-6.5 Å* Dewaxing 50,51 Lube oil dewaxing 800-1250 Vegetable oil from hexane, Food product purification [52][53][54][55] Free fatty acid (FFA) from vegetable oil 150-900…”