Enantioenriched allenylsilanes are used in three-component propargylation reactions with aldehydes and silyl ethers to form syn-homopropargylic ethers that contain an imbedded azide. These materials then undergo thermally induced intramolecular 1,3-dipolar cycloaddition reactions, resulting in unique fused ring systems containing 1,2,3-triazoles. The ability to modify all three components of the reaction allows for expedient access to compounds containing significant structural and stereochemical variation.
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http://dx.doi.org/10.1021/ol902681t | DOI Listing |
Org Biomol Chem
January 2025
Institute of Natural Sciences and Mathematics, Ural Federal University, 51 Lenina Ave., 620000 Ekaterinburg, Russian Federation.
The labile tautomerism of -unsubstituted 5-acyl-4-pyridones, which exist in the form of 4-pyridone or 4-hydroxypyridine depending on the solvent, has been demonstrated. This equilibrium determines the reactivity of pyridones and their ability to undergo substitution reactions of the OH group. A regioselective and convenient method for the construction of functionalized pyrazolo[4,3-]pyridines (30-93%) based on the intramolecular amination reaction of 4-pyridones with hydrazines has been developed.
View Article and Find Full Text PDFJ Org Chem
January 2025
School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, China.
A Mn(III)-mediated radical cascade cyclization of -propargyl enamides with sodium sulfinates was developed. Mechanistic studies indicated that this cascade process is mainly composed of the chemoselective addition of sulfonyl radical to C≡C bond and the regioselective intramolecular 6--trig cyclization. This protocol provided a powerful method for the divergent synthesis of diverse polysubstituted -sulfonylpyridines or 1,2-dihydropyridines just by varying solvent and temperature featuring good functional group compatibility and simple operation.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States.
ConspectusThe manipulation of strained rings is a powerful strategy for accessing the valuable chemical frameworks present in natural products and active pharmaceutical ingredients. Aziridines, the smallest N-containing heterocycles, have long served as building blocks for constructing more complex amine-containing scaffolds. Traditionally, the reactivity of typical aziridines has been focused on ring-opening by nucleophiles or the formation of 1,3-dipoles.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Instituto Universitario de Tecnología Química, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, Universitat Politècnica de València, Av. De los Naranjos s/n, 46022 Valencia, Spain.
Due to their conductive properties and optoelectronic tunability, MXenes have revolutionized the area of electrocatalysis and active materials in supercapacitors. In comparison, there are only a few reports on MXenes as thermal catalysts for general organic reactions. Herein, the unprecedented catalytic activity of TiC MXene for the hydroamination of alkynes is reported, overcoming the limitations of poor activity, lack of selectivity, and stability, which are generally encountered in the solid catalysts known so far.
View Article and Find Full Text PDFOrg Lett
January 2025
School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China.
An unprecedented synergistic copper- and amine-catalyzed cyclization of enynone is reported. This reaction features an efficient and straightforward construction of multisubstituted tetralone through an amine-assisted regioselective oxygen atom transfer process and stereoselective intramolecular Michael addition cyclization. Under dehydrative reaction conditions, the synthesis of tetrahydronaphthylimine derivatives with ketone group tolerance is achieved, which could be challenging via traditional methods.
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