Results 31 to 40 of about 5,810 (212)

Synthesis of 3,4,5-Trisubstituted Isoxazoles in Water via a [3+2]-Cycloaddition of Nitrile Oxides and 1,3-Diketones, β-Ketoesters, or β-Ketoamides: Base-mediated and Keto-enol-controlled Mechanism [PDF]

, 2021
A selective [3+2]-cycloaddition reaction of nitrile oxides and 1,3-diketones, β-ketoesters, or β-ketoamides in water without the need of a metal catalyst is described.
Seong Jong, Kim, Md Imdadul H., Khan, Hoang V., Le, Md Imran, Hossain   +3 more
core   +2 more sources

Photocycloaddition of aromatic and aliphatic aldehydes to isoxazoles: Cycloaddition reactivity and stability studies

Beilstein Journal of Organic Chemistry, 2011
The first photocycloadditions of aromatic and aliphatic aldehydes to methylated isoxazoles are reported. The reactions lead solely to the exo-adducts with high regio- and diastereoselectivities. Ring methylation of the isoxazole substrates is crucial for
Axel G. Griesbeck, Marco Franke, Jörg Neudörfl, Hidehiro Kotaka   +3 more
doaj   +1 more source

Direct Nucleophilic Difluoromethylation of Aromatic Isoxazoles Activated by Electron-Withdrawing Groups Using (Difluoromethyl)trimethylsilane

ScienceOpen Research, 2014
The activation of aromatic diaryl isoxazoles with strong electron-withdrawing groups, such as the nitro, triflyl and the phenylsulfonyl groups, at the 4-position has enabled the first regio- and diastereoselective difluoromethylation at the 5-position of
doaj   +3 more sources

Electrocyclizations of Conjugated Azapolyenes Produced in Reactions of Azaheterocycles with Metal Carbenes

Organics, 2021
Conjugated azapolyenes (azabuta-1,3-dienes, aza-/diaza-/oxaza-/oxadiazahexa-1,3,5-trienes) are highly reactive in electrocyclization reactions, which makes them convenient precursors for the synthesis of a wide range of four-, five-, and six-membered ...
Nikolai V. Rostovskii, Mikhail S. Novikov, Alexander F. Khlebnikov   +2 more
doaj   +1 more source

Synthesis of (4-Trifluoromethyl)isoxazoles through a Tandem Trifluoromethyloximation/Cyclization/Elimination Reaction of α,β-Unsaturated Carbonyls

, 2023
We disclose a metal-free, cascade regio- and stereoselective trifluormethyloximation, cyclization, and elimination strategy with readily available α,β-unsaturated carbonyl compounds to access a wide variety of pharmaceutically potential heteroaromatics ...
Paramita Pattanayak (14784916), Tanmay Chatterjee (1554559)   +1 more
core   +1 more source

Accelerating green heterocyclic synthesis: Convergence of AI, automation, and sustainable chemistry

Bulletin of the Korean Chemical Society, EarlyView.
Green heterocyclic synthesis and data‐driven tools such as AI, high‐throughput experimentation, continuous flow, and self‐driving laboratories have developed largely in parallel. This review connects them and asks how green metrics such as E‐factor and PMI might serve as explicit optimization targets rather than post‐hoc measures, toward sustainable ...
Noor Aisyah Ahmad Shah, Amirreza Mottafegh, Su‐Hyun Yoo, Jongwoon Kim, Minseon Byeon, Juhwan Noh, Yea‐Lee Lee, Jin Suk Myung, Gwang‐Noh Ahn   +8 more
wiley   +1 more source

Nitroimidazoles XIII. Synthesis of Substituted (1-Methyl-5-Nitro-2-Imidazolyl) Isoxazoles [PDF]

Iranian Journal of Chemistry & Chemical Engineering, 1998
The beta0diketone derivatives of nitroimidazole were synthesized from the reaction of magnesium salt of beta-ketoaccids 3 with imidazolide 4. The raction of beta-diketones with hydroxylamine hydrochloride afforded either the isoxazoles or the 5-hydroxyl ...
Abbas Shafiee, Mohammad ALi Ebrahimzadeh
doaj  

A Green Protocol for the Deprotection of ortho‐Nitrobenzyl Esters and Ethers by UVA–LED Irradiation

Chemistry – A European Journal, EarlyView.
This study presents a green and efficient photochemical protocol for the deprotection of ortho‐nitrobenzyl esters or ethers under mild conditions, using UVA‐LED irradiation in methanol. The broad applicability of the protocol was validated in the synthesis of a cytosolic phospholipase A2 inhibitor. ABSTRACT The removal of protecting groups in synthetic
Despoina Poikilidou, Christiana Mantzourani, George Kokotos, Christoforos G. Kokotos   +3 more
wiley   +1 more source

Design, Synthesis and Biological Activity of Regioisomeric 3,5-Disubstituted Isoxazoles and 5-(Hydroxy)Isoxazolines with Aryl and Either (Diterpenylfuran-2-Carbonyl) or (Methylfuran-2-Carbonyl) Moiety

Scientia Pharmaceutica
Alkyn-1,2-diones have gained great attention as useful building blocks in organic synthesis. Regioselective synthetic routes towards 3,5-disubstituted isoxazoles, containing the methylfuroyl or diterpenylfuroyl moiety at the C-3 or C-5 position from ...
Maksim E. Mironov, Dmitry S. Baev, Mohammad S. Hamad, Sergey A. Borisov, Vyacheslav I. Krasnov, Tatyana V. Rybalova, Maksim P. Pitukhin, Irina V. Sorokina, Tatyana G. Tolstikova, Andrey G. Pokrovsky, Anastasia I. Poltanovich, Elvira E. Shults   +11 more
doaj   +1 more source

Carbon Anodes for Low‐Temperature Nonaqueous Alkali Metal‐Ion Batteries

EcoEnergy, EarlyView.
This review summarizes recent progress in carbon anodes for low‐temperature nonaqueous alkali‐metal ion batteries. Fundamental thermodynamic and kinetic limitations are examined, alongside a systematic discussion of graphite, hard carbon, and emerging carbon architectures.
Zhichun Miao, Dandan Yu, Guojie Liu, Yuyang Qin, Jingyun Mou, Wenlong Song, Lu Shi, Zengqin Xiao, Xin Yuan, Huayu Chen, Laishun Qin, Da Chen   +11 more
wiley   +1 more source