• Analytical Science and Technology
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• v.37 no.5
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• pp.306-314
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• 2024

This study describes the liquid chromatographic enantiomer separation of three typical chiral amines (α-methylbenzylamine, 2-amino-4-methyl-1-pentanol, and 1-methylheptylamine) as 2-hydroxynaphthaldimine derivatives using six amylose trisphenylcarbamates derived chiral stationary phases (CSPs). It was observed that the structural nature of three chiral amines and the structures of amylose chiral selectors can affect their chiral recognition ability. Among the three analytes as 2-hydroxynaphthaldimine derivatives, in general, the greatest enantioselectivities of aromatic amine analyte (α-methylbenzylamine) were achieved on amylose trisphenylcarbamate derived CSPs and were followed by amino alcohol analyte (2-amino-4-methyl-1-pentanol), and aliphatic amine analyte (1-methylheptylamine). Also, the enantiodiscrimination abilities obtained on the two CSPs, Chiralpak ID and Chiralpak IF, were selectively higher than the other four amylose trisphenylcarbamate derived CSPs for the studied analytes. The underlying chiral recognition mechanism between 2-amino-4-methyl-1-pentanol as 2-hydroxynaphthaldimine derivatives and amylose tris(3,5-dimethylphenylcarbamate) chiral selector of Chiralpak AD-H and Lux Amylose-1 was elucidated by molecular docking study, and it was observed that the intermolecular hydrogen bonding interactions by hydroxyl moiety on the amino alcohol analyte as 2-hydroxynaphthaldimine derivatives were the main interactive forces driving the chiral separation. The obtained binding energies between 2-amino-4-methyl-1-pentanol analyte as 2-hydroxynaphthaldimine derivative and amylose tris(3,5-dimethylphenylcarbamate) chiral selector were in agreement with the experimentally determined enantioseparation and elution order by chiral HPLC.

• Journal of the Korean Society of Industry Convergence
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• v.12 no.3
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• pp.143-147
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• 2009

The enantioselective reduction of representative prochiral alkyl-aryl ketones with a new chiral alkoxy-amine-aluminum derivatives from aluminum hydride and ${\alpha},{\alpha}$-diphenyl-${\beta}$-amino alcohols, such as (S)-(-)-2-amino-3-methyl-1,1-diphenylbutan-1-ol(AMDPB) and (S)-(-)-2-(diphenylhydroxy-methyl)pyrrolidine(DPHMP), in THF at $0^{\circ}C$ was studied. In the reduction of alkoxy-amine-aluminum derivatives, acetophenone, propiophenone, isopropiophenone, and butyrophenone are reduced to corresponding aromatic secoundary alcohols with 34~60 % enantiomeric excess of (S)-isomers. For such ketones, the optical induction was enhanced by increasing a size of alkyl groups.

• Archives of Pharmacal Research
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• v.27 no.10
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• pp.1009-1015
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• 2004

Quantitative Structure-Resolution Relationship (QSRR) using the Comparative Molecular Field Analysis (CoMFA) software was applied to predict the chromatographic behaviors of chiral drugs with an amine moiety on the chiral cellobiohydrolase (CBH) columns. As a result of the Quantitative CoMFA-Resolution Relationship study, using the partial least square method, prediction of the behavior of drugs with amine moiety upon chiral separation became possible from their three dimensional molecular structures. When a mixed mobile phase of 10 mM aqueous phosphate buffer (pH 7.0) - isopropanol (95 : 5) was employed, the best Quantitative CoMFA-Resolution Relationship, derived from the study, provided a cross-validated $q^2$ = 0.933, a normal $r^2$ = 0.995, while the best Quantitative CoMFA-Separation Factor Relationship, also derived from the study, yielded a cross-validated $q^2$ = 0.939, a normal $r^2$ = 0.991. When all of these results are considered, this QSRR-CoMFA analysis appears to be a very useful tool for the preliminary prediction on the chromatographic behaviors of drugs with an amine moiety inside chiral CBH columns.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.2
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• pp.141-146
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• 2023

The efficient use of a chiral shift agent (3) containing bifunctional group (thiourea and tertiary amine) for the determination of the enantiomeric purity of racemic mixture (Hemiesters) has been studied. The diastereomeric complexes derived from a chiral shift agent (3) with various hemiesters gave rise to well separate signals of the methoxy protons of hemiesters. Good splitting signals for enantiomers of hemiesters in ¹H NMR are originated form the hydrogen bonds between carbonyl groups of hemiester and bifunctional groups of a chiral shift agent (3) such as thiourea moiety and tertiary amine. This study provides a quick and simple way to determine the chiral purity of hemiester using chiral transfer agent (3).

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.1955-1956
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• 2013

• Bulletin of the Korean Chemical Society
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• v.16 no.12
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• pp.1138-1139
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• 1995

• KSBB Journal
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• v.29 no.3
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• pp.205-209
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• 2014

Chromatographic enantiomer resolution of chiral amines was performed on several covalently immobilized and coated chiral stationary phases (CSPs) based on polysaccharide derivatives under the mobile phase conditions containing base or acid or acid/base additive. The chromatographic parameters including separation factors and capacity factors were greatly influenced by the nature of the mobile phase containing base or acid or salt additive as well as the used CSPs. When 0.05% triethylamine/0.05% trifluoroacetic acid as an additive in the mobile phase was used on all CSPs in this study, the greatest enantiomer resolution was observed except for Chiralpak AD. Also, it was shown that the change of base additive into acid or salt in the mobile phase may directly affect chiral recognition mechanisms between the chiral selectors and analytes occurring during enantiomer separation, resulting in the change of elution orders.

• Bulletin of the Korean Chemical Society
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• v.15 no.1
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• pp.53-57
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• 1994

A comparison study on asymmetric borane reduction of ketoxime ethers and N-substituted ketimines possesing C = N double bond mediated by the selected chiral oxazaborolidines (1-6) was investigated. Thus, an aromatic ketoxime O-alkyl ether acetophenone oxime O-methyl ether was reduced to the corresponding amine (1-phenylethylamine 8a) with optical yields, such as 58% ee with 1, 86% ee with 2, 3% ee with 3, 99% ee with 4, 60% ee with 5, and 73% ee with 6. However, the reduction of an aliphatic ketoxime derivative 2-heptanone oxime O-methyl ether provided low optical inductions (7-13% ee). For ketoxime O-trimethylsilyl ethers, the reduction of acetophenone O-trimethylsilyl ether afforded 8a with optical yields which were 90% ee with 1, 40% ee with 2, 2% ee with 3, 62% ee with 4, 5% ee with 5, and 60% ee with 6. The reduction of 2-heptanone O-trimethylsilyl ether also gave the product amine with low optical yields (10-40% ee). In the case of N-substituted ketimines, the reduction of acetophenone N-phenylimine afforded the corresponding amine with 79% ee, 78% ee, 9% ee, 73% ee, 78% ee and 67% ee using 1, 2, 3, 4, 5, and 6, respectively, whereas low optical inductions (5-18% ee) for 2-heptanone N-phenylimine were achieved.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2002.10a
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• pp.82-82
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• 2002

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3185-3186
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• 2013