33817-09-3Relevant articles and documents
Resolution of N-methylamphetamine enantiomers with tartaric acid derivatives by supercritical fluid extraction
Kmecz, Ildiko,Simandi, Bela,Szekely, Edit,Fogassy, Elemer
, p. 1841 - 1845 (2004)
The resolution of N-methylamphetamine (MA) was carried out with the resolution agents O,O′-dibenzoyl-(2R,3R)-tartaric acid monohydrate (DBTA) and O,O′-di-p-toluoyl-(2R,3R)-tartaric acid (DPTTA). After partial diastereomeric salt formation, the unreacted enantiomers were extracted by supercritical fluid extraction (SFE). The effects of resolution agent molar ratio to the racemic mixture (mr), extraction pressure (P) and temperature (T) on the resolution efficiency were studied. The best chiral separation was obtained at a quarter of an equivalent resolution agent molar ratio for both resolution agents. Extraction conditions [pressure (100-200bar), temperature (33-63°C)] did not influence the resolution efficiency, which makes the enantiomer separation robust. In one extraction step, both enantiomers can be produced with high enantiomeric excess (ee) and remarkable yield (Y). Using DBTA as a resolution agent eeE=83%, YE=45% for the extract and eeR=82%, YR=42% for the raffinate were obtained.
Evaluation of the Edman degradation product of vancomycin bonded to core-shell particles as a new HPLC chiral stationary phase
Hellinghausen, Garrett,Lopez, Diego A.,Lee, Jauh T.,Wang, Yadi,Weatherly, Choyce A.,Portillo, Abiud E.,Berthod, Alain,Armstrong, Daniel W.
, p. 1067 - 1078 (2018/08/01)
A modified macrocyclic glycopeptide-based chiral stationary phase (CSP), prepared via Edman degradation of vancomycin, was evaluated as a chiral selector for the first time. Its applicability was compared with other macrocyclic glycopeptide-based CSPs: TeicoShell and VancoShell. In addition, another modified macrocyclic glycopeptide-based CSP, NicoShell, was further examined. Initial evaluation was focused on the complementary behavior with these glycopeptides. A screening procedure was used based on previous work for the enantiomeric separation of 50 chiral compounds including amino acids, pesticides, stimulants, and a variety of pharmaceuticals. Fast and efficient chiral separations resulted by using superficially porous (core-shell) particle supports. Overall, the vancomycin Edman degradation product (EDP) resembled TeicoShell with high enantioselectivity for acidic compounds in the polar ionic mode. The simultaneous enantiomeric separation of 5 racemic profens using liquid chromatography-mass spectrometry with EDP was performed in approximately 3?minutes. Other highlights include simultaneous liquid chromatography separations of rac-amphetamine and rac-methamphetamine with VancoShell, rac-pseudoephedrine and rac-ephedrine with NicoShell, and rac-dichlorprop and rac-haloxyfop with TeicoShell.
Chiral molecular tweezers: Synthesis and reactivity in asymmetric hydrogenation
Lindqvist, Markus,Borre, Katja,Axenov, Kirill,Kótai, Bianka,Nieger, Martin,Leskel?, Markku,Pápai, Imre,Repo, Timo
supporting information, p. 4038 - 4041 (2015/04/14)
We report the synthesis and reactivity of a chiral aminoborane displaying both rapid and reversible H2 activation. The catalyst shows exceptional reactivity in asymmetric hydrogenation of enamines and unhindered imines with stereoselectivities of up to 99% ee. DFT analysis of the reaction mechanism pointed to the importance of both repulsive steric and stabilizing intermolecular non-covalent forces in the stereodetermining hydride transfer step of the catalytic cycle.