Among the methods used for synthesis of functionalized heterocyclic compounds, photochemistry has gained immense popularity due to reactivity intermediates in photoinduced reactions. In this study, we report on effect diaryl disulfides as hydrogen atom transfer catalysts transformations pyrazolo[1,2-a]pyrazolones. After excitation with visible light, these compounds are susceptible C–N bond cle...

The reaction of mercaptoacetic acid esters with pentachloro-2-nitro-1,3-butadiene (1) provides an appropriate precursor for the synthesis of special thiazolidin-4-ones. Applying different anilines as the second constituent for the requisite cyclization step, a series of (Z)-2-allylidenethiazolidin-4-ones was obtained in yields up to 81%. Some subsequent reactions have been examined too, such as...

A one-pot asymmetric Michael addition/hydroalkoxylation sequence, catalyzed by a sequential catalytic system consisting of a squaramide and a silver salt, provides a new series of chiral pyrano-annulated pyrazole derivatives in excellent yields (up to 95%) and high enantioselectivities (up to 97% ee).

In the title pyrazole compound, C(20)H(13)N(3)O(4), an intra-molecular C-H⋯O hydrogen bond generates a seven-membered ring, producing an S(7) ring motif. The essentially planar furan and pyrazole rings [maximum deviations of 0.002 (1) and 0.007 (1) Å, respectively] are coplanar with each other, forming a dihedral angle of 3.06 (10)°. The pyrazole ring forms dihedral angles of 8.51 (9) and 56.81...

Pyrazole-containing compounds represent one of the most influential families N-heterocycles due to their proven applicability and versatility as synthetic intermediates in preparing relevant chemicals biological, physical-chemical, material science, industrial fields. Therefore, synthesizing structurally diverse pyrazole derivatives is highly desirable, various researchers continue focus on thi...

Cellulose sulfuric acid is an efficient metal-free catalyst for the synthesis of 1,3,5-trisubstituted pyrazoles via the condensation of 1,3-diketones and hydrazines. The reaction was carried out in Solvent-free condition at room temperature and the products were isolated in good to excellent yields. Mild reaction conditions, as well as ease of operation and workup are some advantages of the pro...

The 1,3-Dipolar cycloaddition reactions are the classic reaction in modern synthetic organic chemistry. The concept of these reactions was introduced by Huisgen and his co-workers in the early 1960’s. 1,3-Dipolar cycloaddition reactions are simple but powerful tool for the construction of five membered heterocycles such as isoxazoles, isoxazolines, pyrazoles, pyrazolones, 1,2,4-oxadiazolines et...