A practical method for the synthesis of azepine derivatives, a typical seven-membered heterocyclic ring system, was developed and involves the use of hexafluoroantimonic acid to catalyze a formal [3+2+2] cycloaddition of aziridines with two alkynes. This method was applicable to two of the same or different terminal alkynes for the [3+2+2] cycloaddition with unactivated aziridines, and furnished the corresponding azepine derivatives in good yields with good levels of chemo- and regioselectivity. The mechanism was also discussed according to the results of the in situ HRMS and (1)H NMR analysis.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/anie.201310944 | DOI Listing |
Org Lett
January 2025
State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu 730000, P. R. China.
Herein, we present a visible-light-induced protocol for the synthesis of highly functionalized oxo-bridged oxocine skeletons. This method generates carbenes via visible-light-induced ortho-acyl diazo compounds, which are rapidly intercepted by the oxygen atom of an intermolecular acyl group to form a cyclic 1,3-dipole. The in situ generated highly reactive 1,3-dipole undergoes a facile formal [4 + 3] cycloaddition with alkenyl pyrazolinone, yielding [4.
View Article and Find Full Text PDFJ Org Chem
January 2025
Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, 48149 Münster, Germany.
Xanthine nucleosides play a significant role in the expansion of the four-letter genetic code. Herein, 7-functionalized 8-aza-7-deazaxanthine ribo- and 2'-deoxyribonucleosides are described. 2-Amino-6-alkoxy nucleosides were converted to halogenated 8-aza-7-deazaxanthine nucleosides by deamination followed by hydroxy/alkoxy substitution.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
Laboratory of Alternative Energy Conversion Systems, Department of Mechanical Engineering, School of Engineering, University of Thessaly, Pedion Areos 38834, Greece. Electronic address:
The coupling of carbon dioxide (CO) with epoxides to produce cyclic carbonates is a desirable decarbonization approach, but its commercial applicability is still restricted by the costly catalysts required, as well as the need for high temperature and high pressure. Herein, oxygen vacancy-rich defective tungsten oxide (WO) rich in Lewis acid sites was modified by Prussian blue (PB), and the obtained composite reaches up to 94 % styrene carbonate yield (171 mmol gh) at ambient temperature and pressure, exhibiting outstanding advantages in the photocatalytic CO cycloaddition reaction compared with currently reported photocatalysts. It is found that the introduction of PB with photothermal properties significantly enhances the capability of WO to absorb and activate CO and epoxide, along with its light utilization ability.
View Article and Find Full Text PDFEur J Med Chem
December 2024
Department of Natural Products and Medicinal Chemistry, CSIR-IICT Hyderabad, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India. Electronic address:
Investigations into fruit and vegetable processing residues (FVPRs) offer huge opportunities to discover novel therapeutics against many diseases. In this study, detailed investigation of Garcinia mangostana fruit peel extract led to the isolation and identification of ten known compounds (1-10). Further, a new series of α-mangostin derived sulphonyl piperzines, aryl alkynes and 1,2,3-triazole derivatives were synthesized using Huisgen 1,3-dipolar cyclo-addition reaction ("click" chemistry).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Queensland University of Technology, School of Chemistry and Physics, 2 George Street, 4000, Brisbane, AUSTRALIA.
We demonstrate that single-chain nanoparticles (SCNPs) - compact covalently folded single polymer chains - can increase photocatalytic performance of an embedded catalytic center, compared to the comparable catalytic system in free solution. In particular, we demonstrate that the degree of compaction allows to finely tailor the catalytic activity, thus evidencing that molecular confinement is a key factor in controlling photocatalysis. Specifically, we decorate a linear parent polymer with both photoreactive chalcone moieties as well as Ru(bpy)3 catalytic centers.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!