Convenient and general Hg(ii)/Pt(iv) catalyzed syntheses of γ-butyrolactams and α,β-unsaturated γ-butyrolactones/lactams are described via intramolecular electrophilic cyclizations of bromoalkynes with tosylamino and hydroxyl tethers. The reaction features the use of wet solvents, the exclusion of any base and additive, mild conditions and practical yields. We also synthesised few chiral lactams through this pathway. Additionally, it is shown that the NHTs group distanced further from the homopropargylic position assists regioselective bromoalkyne hydration to yield useful α-bromoketones. Furthermore, Boc protected bromo homo propargyl amines undergo 6-endo-dig cyclization through Boc oxygen to give bromomethylene substituted oxazinones.
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http://dx.doi.org/10.1039/c5ob02125a | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Cardiff University, School of Chemistry, Park Place, Main Building, CF10 3AT, Cardiff, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
Despite the remarkable advancements in hypervalent iodine chemistry, exploration of bromine and chlorine analogues remains in its infancy due to their difficult synthesis. Herein, we introduce six-membered cyclic λ3-bromanes and λ3-chloranes. Through single-crystal X-ray structural analyses and conformational studies, we delineate the crucial bonding patterns pivotal for the thermodynamic stability of these compounds.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Department of Chemistry and Chemistry Institution for Functional Materials, Pusan National University, Busan 46241, Republic of Korea.
ConspectusControlling selectivity through manipulation of reaction intermediates remains one of the most enduring challenges in organic chemistry, providing novel solutions for selective C-C π-bond functionalization. This approach, guided by activation principles, provides an effective method for selective functional group installation, enabling direct synthesis of organic molecules that are inaccessible through conventional pathways. In particular, the selective functionalization of N-conjugated allenes and alkynes has emerged as a promising research focus, driven by advances in controlling reactive intermediates and activation strategies.
View Article and Find Full Text PDFJ Photochem Photobiol B
January 2025
College of Science, Northeast Forestry University, Harbin 150040, China. Electronic address:
Apigenin (Api), a flavonoid possessing dual features of antioxidant activity and intramolecular hydrogen bond (IMHB), is subjected to an external electric field (EEF) to investigate its excited-state antioxidant activity after excited state intramolecular proton transfer (ESIPT) behavior employing the density functional theory (DFT) and time-dependent DFT (TD-DFT) methods, as well as molecular docking. The existence of IMHB is demonstrated by structural parameters and AIM topological analysis, where Api in the enol form under an EEF of +60 × 10 a.u.
View Article and Find Full Text PDFJ Mol Model
December 2024
Department of Chemistry, Faculty of Science, Ege University, TR-35100, Bornova, Izmir, Türkiye.
Context: Isatin-Schiff bases have wide applications in chemistry. The π conjugated electronic system and heterocylic structure of these materials make them valuable for use as photosensitized materials. The delocalization of π-electrons throughout the structure causes the UV-vis absorption spectra to shift to longer wavelengths.
View Article and Find Full Text PDFJ Org Chem
December 2024
Laboratory of organic and metal-organic nitrogen-oxygen systems, N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospect, 47, Moscow 119991, Russian Federation.
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