N-Vinyl nitrones derived from fluorenone have been prepared via a copper-mediated coupling between fluorenone oxime and vinyl boronic acids. These compounds undergo subsequent rearrangement and addition reactions that are distinct from the traditional [3 + 2] cycloaddition reactivity of nitrones. Thermal rearrangements of fluorenone N-vinyl nitrones give spiroisoxazolines, while treatment with ...

Conditions allowing the one pot 2,5-diheteroarylation of 2,5-dibromothiophene derivatives in the presence of palladium catalysts are reported. Using KOAc as the base, DMA as the solvent and only 0.5-2 mol % palladium catalysts, the target 2,5-diheteroarylated thiophenes were obtained in moderate to good yields and with a wide variety of heteroarenes such as thiazoles, thiophenes, furans, pyrrol...

Thermal properties of azidohetarenes without reactive ortho-substituents, obtained by DSC analysis, were compared with the DSC data of ortho-phenyl and ortho-acyl substituted azidohetarenes, which give ring closure reactions either to indoles or to five-membered heterocycles such as isoxazoles. The reaction temperatures and reaction enthalpies give both information to prepare the reaction condi...

pyrazoles and isoxazoles are well-known important heterocyclic compounds that due to their participation in the structure of many drugs are very important. pyrazoles and isoxzaloes can be prepared by oxidation of pyrazolines and isoxazolines respectively. in this work, trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxalane (dhpdmdo)/nh4i has been used as a new, powerful, nearly green, effective and...

Pyrazoles and isoxazoles are well-known important heterocyclic compounds that due to their participation in the structure of many drugs are very important. Pyrazoles and isoxzaloes can be prepared by oxidation of pyrazolines and isoxazolines respectively. In this work, trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxalane (DHPDMDO)/NH4I has been used as a new, powerful, nearly green, effective and...

Pyrazoles and isoxazoles are well-known important heterocyclic compounds that due to their participation in the structure of many drugs are very important. Pyrazoles and isoxzaloes can be prepared by oxidation of pyrazolines and isoxazolines respectively. In this work, trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxalane (DHPDMDO)/NH4I has been used as a new, powerful, nearly green, effective and...

In the title compound, C(10)H(10)ClNO, the benzoisoxazole ring is almost planar (r.m.s. deviation = 0.0121 Å) and the chloro substituent in the side chain is anti-clinal relative to the N-C bond of the isoxazole ring. In the crystal, adjacent mol-ecules are linked via a pair of weak C-H⋯N hydrogen bonds, forming dimers through a cyclic R(2) (2)(8) association.

In the title compound, C(13)H(11)ClN(2)O(3), the nine-membered bicycle includes an oxime group having the C=N group in an E configuration. The isoxazole ring is almost planar [r.m.s. deviation = 0.0056 Å]; the dihedral angle between the isoxazole and 4-chloro-phenyl ring is 75.60 (5)°. In the crystal, inter-molecular O-H⋯N(isoxazole) hydrogen bonds give rise to chains running along the b axis.

5-Hydroxy-3-oxopent-4-enoic acid esters can be efficiently transformed into the stable bis-potassium salts of the corresponding 5-hydroxy-3-oxopent-4-enoic acids, from which the sensitive acids are released in situ, the latter being converted into substituted 4-hydroxy-2H-pyran-2-ones, pyrazoles and isoxazoles under mild conditions; the efficiency of this method is demonstrated by the first syn...

A new protocol for synthesizing different functionalized isoxazoles is provided. Carbamoylnitrile oxide generated from nitroisoxazolone underwent inverse electron-demand 1,3-dipolar cycloaddition with 1,3-dicarbonyl compounds in the presence of magnesium acetate that formed magnesium enolate in situ. Although electron-deficient trifluoroacetoacetate did not undergo this cycloaddition under the ...