Recent advances in isoxazole chemistry

Combined experimental and theoretical studies of regio- and stereoselectivity in reactions of β-isoxazolyl- and β-imidazolyl enamines with nitrile oxides

“…Isoxazoles have been found in natural products [1], and they exhibit anticancer [2], antiviral [1], anti-inflammatory [3], antidiabetic [4], anti-Alzheimer [5] and many other types of biological activity [6]. Isoxazolines and isoxazoles have been applied as chemosensors, liquid crystalline compounds, ligands for asymmetric synthesis, and they are also convenient reagents in organic synthesis [1].…”

“…Isoxazolines and isoxazoles have been applied as chemosensors, liquid crystalline compounds, ligands for asymmetric synthesis, and they are also convenient reagents in organic synthesis [1]. Although bicyclic assemblies of azoles exhibit interesting chemical properties and biological activities [1,7–11] isoxazoles conjugated to other azole rings are poorly presented in the literature in comparison with monocyclic and fused derivatives [1,6]. …”

Oxazole and Isoxazole Chemistry in Crop Protection

“…The oxazoles and isoxazoles constitute a fascinating class of five‐membered heterocyclic compounds with one nitrogen and one oxygen ring atom, chemically related to the other azoles, such as imidazole, pyrazole, thiazole, and isothiazole. The process in preparative investigations on oxazoles , isoxazoles , oxazolines , isoxazolines , oxazolidines , isoxazolidines , oxazolones , isoxazolones , benzoxazoles , and benzisoxazoles has been summarized in exhaustive reviews. Also, the application of most of these heterocyclic scaffolds in medicinal chemistry has been reviewed recently, just to mention the broad pharmacological (e.g., anticancer, antimicrobial, antidiabetic, anti‐inflammatory, and anticonvulsant) activity of benzoxazoles or the specific significance of isoxazoles for neuropsychiatric therapeutics .…”

Fe(II)/Et3N-Relay-catalyzed domino reaction of isoxazoles with imidazolium salts in the synthesis of methyl 4-imidazolylpyrrole-2-carboxylates, its ylide and betaine derivatives

“…Quite recently this isomerization has been used for the preparation of substituted pyrrole-2-carboxylic acid derivatives by the domino reaction of 3-aryl-5-methoxyisoxazoles with 1,3-dicarbonyl compounds under relay catalysis [31]. Taking into account the facts discussed above, we envisioned that the synthesis of 5-alkoxycarbonylpyrrol-3-ylimidazolium salts 1 could be carried out starting from easily available 5-alkoxyisoxazoles 7 [32–33] and 1-alkyl-3-phenacyl-1 H -imidazolium bromides 9 according to Scheme 2, whereby excluding the isolation of often unstable 2 H -azirines [34]. …”