The preparation of the (1-naphthyl)(trifluoromethyl) O-carboxy-anhydride 1 and its use as a chiral derivatizing agent with several alpha-chiral primary amines are reported. The very large Delta delta(RS) values observed in (1)H NMR have been correlated with a marked preference of the corresponding alpha-hydroxy-amides for the eclipsed conformation. In comparison, the related O-methylated amides are shown to adopt staggered conformations, which substantiates the critical role of intramolecular hydrogen bonding in maximizing the anisotropic effect.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ol801930m | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A Protocol for GC-MS Profiling of Chiral Secondary Amino Acids.
Methods Mol Biol
January 2025
Laboratory of Analytical Biochemistry & Metabolomics, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.
A simple analytical workflow is described for gas chromatographic-mass spectrometric (GC-MS)-based chiral profiling of secondary amino acids (AAs) in biological matrices. The sample preparation is carried out directly in aqueous biological sample extracts and involves in situ heptafluorobutyl chloroformate (HFBCF) derivatization-liquid-liquid microextraction of nonpolar products into hexane phase followed by subsequent formation of the corresponding methylamides from the HFB esters by direct treatment with methylamine reagent solution. The (O, N) HFB-butoxycarbonyl-methylamide AA products (HFBOC-MA) are separated on a Chirasil-L-Val capillary column and quantitatively measured by GC-MS operated in selected ion monitoring (SIM) mode.
View Article and Find Full Text PDFImidazolium-based ionic liquid functionalized chiral metal-organic framework as an efficient catalyst for asymmetric catalytic sulfoxidation.
RSC Adv
January 2025
School of Chemistry and Chemical Engineering, Shanxi University Taiyuan 030006 China
Ionic liquid (IL) units in heterogeneous catalysts exhibit synergistic effects to enhance catalytic performance and stabilize catalytically active centers, while also preventing the degradation of catalysts during the reaction process. Ionic liquid units in IL-functionalized CMOF catalysts enhance their catalytic performance in a synergistic manner. However, not only are the yields of IL-functionalized CMOFs obtained with post-synthesis methods low, but they also lead to blocking of the MOF pores and leaching of the ionic liquid.
View Article and Find Full Text PDFEnantioselective Analysis and Separation of Two β-Blockers via Derivatization Approach.
Chirality
January 2025
Department of Chemistry, Shyam Lal College, University of Delhi, New Delhi, India.
Enantiomeric analysis of chiral drugs is very significant, as their enantiomers display different pharmacological or toxicological behavior towards living systems. Among these drugs, β-blockers are available as racemates, where their enantiomers display different pharmacological effects. Herein, we report enantioselective separation of two β-blockers, namely, atenolol and sotalol, using a derivatization approach.
View Article and Find Full Text PDFEnantioselective Synthesis of Chiral β-Amino Phosphorus Derivatives via Nickel-Catalyzed Asymmetric Hydrogenation.
J Am Chem Soc
January 2025
Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
Compared with chiral β-amino phosphorus compounds, which can be easily derived from natural optically pure α-amino acids, obtaining chiral β-amino phosphorus derivatives remains a challenge. These derivatives, which cannot be derived from chiral natural amino acids, possess unique biological activities or potential catalytic activities. Herein, highly enantioselective hydrogenation for the preparation of chiral β-amino phosphorus derivatives from -β-enamido phosphorus compounds is reported by using a green and low-cost earth-abundant metal nickel catalyst (13 examples of 99% ee).
View Article and Find Full Text PDFStructural Elucidation and Antiviral Properties of Pannosides from the Halophyte L.
Mar Drugs
November 2024
College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon 21983, Republic of Korea.
Four previously undescribed pentacyclic triterpenoid saponins, pannosides F-I (-), were isolated from the halophyte L. (), and their chemical structures were elucidated using 1D and 2D NMR spectroscopy and mass spectrometry. Comprehensive structural analysis revealed the presence of distinct aglycone and glycosidic moieties, along with complex acylation patterns.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!