The first total synthesis of marthiapeptide A is reported. Two synthetic procedures are described: the first, which was unsuccessful, attempts to close the ring at position I, and the second, which was successful, closes the ring at position II. It appears that the first route was unsuccessful because it required cyclization next to the rigid thiazole moiety, whereas the second route closed next to the more flexible thiazoline ring.
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http://dx.doi.org/10.1021/acs.orglett.5b02574 | DOI Listing |
Phys Chem Chem Phys
January 2025
Key Laboratory of Soft Chemistry and Functional Materials of MOE, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P. R. China.
2-(2-Hydroxyphenyl)benzothiazole (HBT) derivatives with donor-π-acceptor (D-π-A) structure have received extensive attention as a class of excited state intramolecular proton transfer (ESIPT) compounds in the fields of biochemistry and photochemistry. The effects of electron-donors (triphenylamine and anthracenyl), the position of substituents and solvent polarity on the fluorescence properties and ESIPT mechanisms of HBT derivatives were investigated through time-dependent density functional theory (TDDFT) calculations. Potential energy curves (PECs) and frontier molecular orbitals (FMOs) reveal that the introduction of the triphenylamine group on the benzene ring enhances intramolecular HB, thereby benefiting the ESIPT process.
View Article and Find Full Text PDFJ Org Chem
January 2025
Applied Chemistry and Chemical Engineering, Graduate School of Engineering, Kogakuin University, Nakano 2665-1, Hachioji, Tokyo 192-0015, Japan.
The cascade aza-Prins/Friedel-Crafts reaction of homocinnamyloxycarbamate with electron-rich aromatic aldehydes has been successfully established. Most of the aromatic aldehydes react with the carbamate stereoselectively to generate -hydroindeno-1,2-oxazinanes. However, the cascade reactions of benzaldehydes bearing two methoxy groups at the -positions exhibit a unique stereochemical profile.
View Article and Find Full Text PDFChemphyschem
January 2025
Keio University Faculty of Science and Technology Graduate School of Science and Technology: Keio Gijuku Daigaku Rikogakubu Daigakuin Rikogaku Kenkyuka, Applied Physics and Physico-Informatics, 3-14-1 Hiyoshi, Kohoku-ku, 223-8522, Yokohama, JAPAN.
Understanding the reversible transformation between two isomeric states of organic molecules under external stimulation is essential for advancing single-molecule device development. Photochromic diarylethene (DAE) derivatives are promising candidates for single molecular switching elements. This study investigates the single-molecule reactions of the closed-form isomer of a DAE derivative on Cu(111) using scanning tunneling microscopy (STM).
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States.
The unique reactivity of molecules under force commands an understanding of structure-mechanochemical activity relationships. While conceptual frameworks for understanding force transduction in many systems are established, systematic investigations into force-coupled molecular torsions are limited. Here, we describe a novel fluorenyl naphthopyran mechanophore for which mechanical force is uniquely coupled to the torsional motions associated with the overall chemical transformation as a result of the conformational rigidity imposed by the fluorene group.
View Article and Find Full Text PDFACS Med Chem Lett
January 2025
Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Korea.
The A Adenosine Receptor (AAR) is an important therapeutic target due to its role in inflammation and immune response regulation. Herein, we synthesized and evaluated 5'-deoxy-adenosine derivatives with oxygen at the 4'-position, comparing them to previously studied 4'-thionucleosides. Compound exhibited the highest binding affinity ( = 5.
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