A metal-free approach for in situ regioselective synthesis of isoxazoles via 1,3 dipolar cycloaddition reaction of nitrile oxide with propargyl bromide
Herein, we report a multi-component reaction (MCRs) to synthesise a range of 3-phenyl-5-(bromomethyl)isoxazoles analogues using DMF/water mixture as solvent, providing desired products in good to excellent yields. The reaction efficiently involves the 1,3-dipolar cycloaddition reaction between propargyl bromide and in situ-generated α-chloro aldoximes. The protocol proceeded well under mild metal-free conditions and showed a tolerance for a wide range of substituents. Graphical abstract: [Figure not available: see fulltext.]
Design, synthesis, and herbicidal activities of novel 2-cyanoacrylates containing isoxazole moieties
A series of novel 2-cyanoacrylates containing an isoxazole moiety were designed and synthesized. Their structures were characterized by 1H NMR and elemental analysis (or high-resolution mass spectrometry). Their herbicidal activities against four species were evaluated, and the results indicated that some of the title compounds showed excellent herbicidal activities against rape and amaranth pigweed in postemergence treatment even at a dose of 75 g/ha.