Untitled

Shironina, T. M.; Игидов, Н. М.; Козьминых, Е. Н.; Kon'shina, L. O.; Kasatkina, Yu. S.; Козьминых, В. О.

doi:10.1023/a:1013431407273

Cited by 21 publications

(12 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A third condensation with hydrazine hydrate [20,21] furnished the key intermediate 3,3Ј-bicamphorpyrazole (bcpz) 2 as an insoluble powder in 91 % yield. After several attempts to solubilize 2, we found that prolonged heating under basic conditions resulted in complete solvation of the 3,3Ј-bipyrazolate, which in turn provided a useful indicator of the reaction progress.…”

Section: Resultsmentioning

confidence: 99%

Bulky and Modular 3,3′‐Bipyrazoles as Ligands: Synthesis, Characterization, and Catalytic Activity of Pd Complexes

et al. 2011

View full text Add to dashboard Cite

In the present study, the properties of a new bidentate N,N′-chelating ligand class that bears an electron-excessive 3,3′-bipyrazole core have been investigated. The ligands are easily accessible in a three-step procedure by condensation with diethyl oxalate followed by tandem condensation with hydrazine hydrate and finally by aryl- or alkylation exclusively at the N-1,1′-pyrazole positions to furnish overall eleven new ligands with different electronic properties. After structural analysis of the ligands, their coordination to palladium, copper, and cobalt has been studied. These ligands coordinate the 2,2′-pyrazolyl nitrogen atoms in a bidentate fashion to the metals to realize complexes with an (L)MX₂ motif. We present two crystal structures of Pd and Cu complexes, which to the best of our knowledge represent the first d⁸ and d⁹ 2,2′-bipyrazole compounds coordinated through bidentate complexation. Initial catalytic experiments have been performed with palladium complexes with three bipyrazole ligands of this new class; the palladium-catalyzed copper-free Wacker oxidation of different alkenes showed superior activity compared to 2,2′-bipyridines. We attribute this to a higher redox potential of the 3,3′-bipyrazoles, which are ― besides electronic effects ― also strongly influenced by steric effects. These might be enforced by the extended ligand backbone, the choice of the wingtip substitution, and the smaller coordination cavity within the N²,N^2′ atoms compared to 2,2′-bipyridine ligands

show abstract

Section: Resultsmentioning

confidence: 99%

Bulky and Modular 3,3′‐Bipyrazoles as Ligands: Synthesis, Characterization, and Catalytic Activity of Pd Complexes

et al. 2011

View full text Add to dashboard Cite

show abstract

“…The result of our investigation was given below (Scheme 1). The first step involves the synthesis of tetraketones 3a-e 13,14,15 by condensation of methyl ketones 1a-e with diethyl oxalate 2. The second step consists of the condensation of these compounds with hydrazine hydrate in refluxing ethanol yielding the corresponding bipyrazole derivatives 4a-e. 15,16 These compounds have high melting points and low solubility properties in organic solvents.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of new 1,1’-di(4-nitro or 2-nitrophenyl)-5,5’-disubstituted-3,3’-bipyrazoles under microwave irradiation and classical heating conditions

Bouabdallah¹,

Touzani²,

Zidane³

et al. 2006

Arkivoc

View full text Add to dashboard Cite

show abstract

“…The structural features of compounds synthesized were established from the data of IR and NMR spectra and X-ray diffraction (XRD) analysis.Reactions of 1,3,4,6-tetracarbonyl compounds, in particular, of 1,6-disubstituted 1,3,4,6-tetraketones with arylhydrazines resulted in heterocyclization giving biologically active pyrazole derivatives [1][2][3][4].No published information exists beside our preliminary communication [5] on the reaction of 1,3,4,6-tetracarbonyl compounds having terminal ester groups with 2,4-dinitrophenylhydrazine. …”

mentioning

confidence: 99%

“…Reactions of 1,3,4,6-tetracarbonyl compounds, in particular, of 1,6-disubstituted 1,3,4,6-tetraketones with arylhydrazines resulted in heterocyclization giving biologically active pyrazole derivatives [1][2][3][4].…”

mentioning

confidence: 99%

Reaction of 3,4-dioxohexane-1,6-dioic acid esters with 2,4-dinitrophenylhydrazine

et al. 2016

View full text Add to dashboard Cite

Reaction was studied of 3,4-dihydroxyhexa-2,4-diene-1,6-dioic acid esters with 2,4dinitrophenylhydrazine that led to the formation of esters of (3E)-3-[2-(2,4-dinitrophenyl)-hydrazinylidene]-4oxohexane-1,6-dioic and (3E,4E)-3,4-bis[2-(2,4-dinitrophenyl)hydrazinylidene]-hexane-1,6-dioic acids. The structural features of compounds synthesized were established from the data of IR and NMR spectra and X-ray diffraction (XRD) analysis.Reactions of 1,3,4,6-tetracarbonyl compounds, in particular, of 1,6-disubstituted 1,3,4,6-tetraketones with arylhydrazines resulted in heterocyclization giving biologically active pyrazole derivatives [1][2][3][4].No published information exists beside our preliminary communication [5] on the reaction of 1,3,4,6-tetracarbonyl compounds having terminal ester groups with 2,4-dinitrophenylhydrazine.

show abstract

Untitled

Cited by 21 publications

References 2 publications

Bulky and Modular 3,3′‐Bipyrazoles as Ligands: Synthesis, Characterization, and Catalytic Activity of Pd Complexes

Bulky and Modular 3,3′‐Bipyrazoles as Ligands: Synthesis, Characterization, and Catalytic Activity of Pd Complexes

Synthesis of new 1,1’-di(4-nitro or 2-nitrophenyl)-5,5’-disubstituted-3,3’-bipyrazoles under microwave irradiation and classical heating conditions

Reaction of 3,4-dioxohexane-1,6-dioic acid esters with 2,4-dinitrophenylhydrazine

Contact Info

Product

Resources

About