19701-89-4Relevant articles and documents
1,2-NAPHTHOQUINONE DERIVATIVE AND METHOD FOR PREPARING SAME
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Paragraph 0302; 0304, (2016/11/21)
Disclosed are a compound represented by Formula (1), or a pharmaceutically acceptable salt, hydrate, solvate, prodrug, tautomer, enantiomer, or pharmaceutically acceptable diastereomer thereof, a method of preparing the same, and a pharmaceutical composition, which have effects for treatment or prevention of metabolic syndromes, comprising the same: wherein R1to R6, X1 to X4, and n are the same as defined in Claim 1.
Resolution of racemic N-benzyl α-amino acids by liquid-liquid extraction: A practical method using a lipophilic chiral cobalt(III) salen complex and mechanistic studies
Dzygiel, Pawel,Reeve, Toby B.,Piarulli, Umberto,Krupicka, Martin,Tvaroska, Igor,Gennari, Cesare
supporting information; experimental part, p. 1253 - 1264 (2009/04/07)
The efficient resolution of racemic N-benzyl α-amino acids (N-Bn-AA) has been achieved by a liquid-liquid extraction process using the lipophilic chiral salen-cobalt(III) complex [CoIII(3)(OAc)]. As a result of the resolution by extraction, one enantiomer (S) of the N-benzyl α-amino acid predominated in the aqueous phase, while the other enantiomer (R) was driven into the organic phase by complexation to cobalt. The complexed amino acid (R) was then quantitatively released by a reductive (CoIII→Co II) counter-extraction with aqueous sodium dithionite or L-ascorbic acid in methanol. The reductive cleavage allowed to recover the [Co II(3)] complex in good yield, which could be easily re-oxidized to [CoIII(3)(OAc)] with air/AcOH and reused with essentially no loss of reactivity and selectivity. Investigation on the nitrogen substitution indicates that the presence of a single benzyl group on the amino acid nitrogen is important to obtain high enantioselectivity in the extraction process. The kinetic vs. thermodynamic nature of the resolution process was also investigated with an enantiomeric exchange experiment, which shows that the liquid-liquid extraction with [CoIII(3)-(OAc)] is an equilibrium process operating under thermodynamic control. In the absence of a suitable crystal structure of the [CoIII(3)(N-Bn-AA)] complexes, computational and spectroscopic studies were used to investigate how the N-benzyl α-amino acids are accommodated in the "binding pocket" of the chiral cobalt complex. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Studies on the Stereochemical Characterization of N-Methylated Amino Acids
Ang, Siau-Gek,Low, Siew Hsien
, p. 1591 - 1601 (2007/10/02)
Various methods that could be to determine the absolute configuration of N,N-dimethylated amino acids were investigated.Two methods utilizing 1H nuclear magnetic resonance (n.m.r.) spectroscopy were successful.The first involved the conversion of the N,N-