33875-38-6Relevant academic research and scientific papers
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.
Pseudoephedrine-Directed Asymmetric α-Arylation of α-Amino Acid Derivatives
Atkinson, Rachel C.,Fernández-Nieto, Fernando,Mas Rosell?, Josep,Clayden, Jonathan
, p. 8961 - 8965 (2015/08/03)
Available α-amino acids undergo arylation at their α position in an enantioselective manner on treatment with base of N′-aryl urea derivatives ligated to pseudoephedrine as a chiral auxiliary. In situ silylation and enolization induces diastereoselective migration of the N′-aryl group to the α position of the amino acid, followed by ring closure to a hydantoin with concomitant explulsion of the recyclable auxiliary. The hydrolysis of the hydantoin products provides derivatives of quaternary amino acids. The arylation avoids the use of heavy-metal additives, and is successful with a range of amino acids and with aryl rings of varying electronic character.
Enantioselective Synthesis of α-Quaternary Amino Acids by Alkylation of Deprotonated α-Aminonitriles
Netz, Isabelle,Kucukdisli, Murat,Opatz, Till
, p. 6864 - 6869 (2015/10/06)
A series of α-quaternary arylglycines were prepared in high optical purity (up to 98% ee) by α-alkylation of deprotonated α-aminonitriles derived by the Strecker reaction from (4S,5S)-5-amino-2,2-dimethyl-4-phenyl-1,3-dioxane. The procedure includes only chromatographic purification of the final products and is devoid of chromatography or crystallization operations on intermediates to raise the optical purity.
COMPOSITIONS AND METHODS FOR CYCLOFRUCTANS AS SEPARATION AGENTS
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Page/Page column 45-49; 61, (2010/12/31)
The present invention relates to derivatized cyclofructan compounds, compositions comprising derivatized cyclofructan compounds, and methods of using compositions comprising derivatized cyclofructan compounds for chromatographic separations of chemical species, including enantiomers. Said compositions may comprise a solid support and/or polymers comprising derivatized cyclofructan compounds.
2-AMINO-2-PHENYL-ALKANOL DERIVATIVES, THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM
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Page/Page column 12, (2009/08/16)
2-amino-2-phenyl-alkanol ester derivatives of general formula (I) in which: R1 is H, straight or branched 1 to 4C alkyl, straight or branched 2 to 4C alkyl substituted by OH, alkoxy, alkylthio, acyloxy, NH2, alkylamino, dialkylamino, alkylcarba
Enantioselective nucleophilic catalysis: The synthesis of aza-β-lactams through [2+2] cycloadditions of ketenes with azo compounds
Berlin, Jacob M.,Fu, Gregory C.
supporting information; experimental part, p. 7048 - 7050 (2009/04/07)
(Chemical Equation Presented) Get ready for take off: A planar-chiral derivative of 4-pyrrolidinopyridine (1) mediates the title transformation (see scheme) in a convergent manner with good enantioselectivity, thus giving the first catalytic asymmetric synthesis of aza-β-lactams.
New methodology for the synthesis of α,α-dialkylamino acids using the "self-regeneration of stereocenters" Method: α-ethyl-α-phenylglycine
O'Donnell, Martin J.,Fang, Zhiqiang,Ma, Xiaojun,Huffman, John C.
, p. 617 - 630 (2007/10/03)
The stereoselective room temperature ethylations of protected oxazolidinones from phenylglycine by phase-transfer catalysis or with KOtBu as base are used to prepare optically active α-ethyl-α-phenylglycine.
SINTESIS ASIMETRICA DE α-FENILAMINOACIDOS
Cativiela, Carlos,Villegas, Maria D. Diaz de,Galvez, Jose A.,Lapena, Yolanda
, p. 432 - 437 (2007/10/02)
A new synthetic strategy to obtain α-phenylamino acids in enantiomerically pure form is described.The new route is based on the highly diastereoselective alkylation of (1S,2R,4R)-10-dicyclohexylsulfamoylisobornyl 2-phenylcyanoacetate and subsequent Curtiu
