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The effective and mild [4+1] annulation of ninhydrin-derived MBH carbonates with α,β-unsaturated ketones has been developed, providing a wide range of multisubstituted furans in high yields (up to 90%) with excellent β-regioselectivities. In contrast, the polysubstituted cyclopentenes bearing dispiro-bisindanedione motifs were obtained classical [3+2] annulations by employing ninhydrin-derived MBH carbonates with 2-arylidene-1,3-indandiones under the same catalytic conditions. Furthermore, the structures of two kinds of cycloadducts were straightforwardly confirmed through X-ray diffraction analysis.
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http://dx.doi.org/10.1039/d3cc06276g | DOI Listing |
Org Lett
September 2025
Key Lab of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Wushan Rd-381, Guangzhou 510641, P.R. China.
Herein, we report the first regio- and enantioselective synthesis of tetrahydropyrido[2,3-]pyrazines using a chiral iridacycle catalyst. Pyridyl diamines and diketones undergo sequential annulation and asymmetric transfer hydrogenation of the generated pyrido[2,3-]pyrazine intermediates. This method provides diverse fused N-heterocycles in high yields (up to 95%) and enantioselectivity (98.
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September 2025
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, P. R. China.
An iron(III)-catalyzed methanesulfonic-acid-mediated [3 + 2 + 1C] annulation of enaminones assembling a 1,2-dihydropyridine (1,2-DHP) scaffold has been developed for the first time. This approach facilitates the rapid synthesis of 2-hydroxy-1,2-DHP derivatives in moderate to excellent yields with a broad substrate scope under mild conditions. The employment of 1,3-dioxolane as both a 1C synthon and solvent enables simultaneous incorporation of both a carbon atom and a hydroxy group into 1,2-DHPs.
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September 2025
Henan Provincial Engineering and Technology Research Center for Precise Synthesis of Fluorine-Containing Drugs. College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, 455000, P. R. China.
In this work, we report a novel I-mediated ring-opening -difunctionalization of cyclopropyl alcohols with enaminones for the first time. The selective [3 + 2] annulation instead of [3 + 3] annulation under metal-free conditions enables a straightforward and efficient synthesis of structurally important 2,4-diacylpyrroles. Notably, this methodology dispenses with metal catalysts, proceeds under mild reaction conditions, and features not only simple operation but also suitability for gram-scale preparation and late-stage functionalization of complex bioactive molecules.
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September 2025
Jiangxi Province Key Laboratory of Natural and Biomimetic Drugs Research, College of Chemistry and Materials, Jiangxi Normal University, Nanchang 330022, China.
The annulation reaction of β-methyl enaminones with alkynones leading to the synthesis of methylene-functionalized 1,2-dihydropyridines (1,2-DHPs) has been realized. In the presence of only CsCO, 1,2-DHPs have been synthesized with a broad scope and generally high efficiency via the novel transformation of the γ-C(sp)-H bond in enaminones. In addition, the application of the method has been demonstrated by the one-step transformation of the 1,2-DHP products into fused tricyclic scaffolds featuring an indole-pyridine hybrid via dual C-H activation.
View Article and Find Full Text PDFOrg Biomol Chem
September 2025
Department of Chemistry, National Institute of Technology Calicut, 673601, Kozhikode, Kerala, India.
We report here an efficient and sustainable protocol for the direct synthesis of 2,3-dihydroperimidine derivatives dehydrogenative C-N coupling, utilizing a recyclable Fe single-atom catalyst supported on nitrogen-doped carbon (Fe-N-C). The catalyst was synthesized by encapsulating ferrocene within the ZIF-8 framework, followed by pyrolysis. The catalyst exhibited excellent activity, stability, and recyclability, facilitating the transformation of diverse primary alcohols, including aryl/heteroaryl methanol and aliphatic alcohols, into the desired products in moderate to good yields.
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