scholarly journals [18-C-6H3O+]: an in-situ generated macrocyclic complex and an efficient, novel catalyst for synthesis of pyrano[2,3-c]pyrazole derivatives

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Manisha Mishra ◽  
K. J. Jomon ◽  
V. R. Sriram Krishnan ◽  
Aatika Nizam
Author(s):  
М.П. Карушев ◽  
А.М. Тимонов

The dependence of the conductivity in thin films of polymer complexes of nickel with N4 ligands with macrocyclic and chelate structure on the doping level has been studied by the electrochemical in-situ conductance method. The electrochemical conductivity window of polymers depends on the structure of the monomers and approached 1.2 V for the macrocyclic complex. Electrochemical doping changes the electrical resistance of the investigated materials by 4 orders of magnitude


2018 ◽  
Vol 73 (7) ◽  
pp. 467-480 ◽  
Author(s):  
Eva Pušavec Kirar ◽  
Uroš Grošelj ◽  
Amalija Golobič ◽  
Franc Požgan ◽  
Sebastijan Ričko ◽  
...  

Abstract [3+2] cycloadditions of ynones derived from glycine and (S)-alanine and some other dipolarophiles with azomethine imines, nitrile oxides, diazoacetate, and azidoacetate were studied. The dipolarophiles were obtained from α-amino acids, either by the reduction of the carboxy function with ethynylmagnesium bromide or by propiolation of the amino function. Cu-catalyzed cycloadditions of ynones to azomethine imines were regioselective and gave the expected cycloadducts as inseparable mixtures of diastereomers. In some instances, further oxidative hydrolytic ring-opening took place to afford 3,3-dimethyl-3-(1H-pyrazol-1-yl)propanoic acids. Acid-catalyzed cycloadditions of 3-butenone were also regioselective and provided mixtures of diastereomeric cycloadducts, which were separated by chromatography. In the reactions of title ynones with alkyl diazoacetates, in situ-formed benzonitrile oxides, and tert-butyl azidoacetate, all cycloadducts were obtained as single regioisomers. The structures of all novel compounds were established by nuclear magnetic resonance and X-ray diffraction.


2021 ◽  
Author(s):  
Esteban Gioria ◽  
Chiara Signorini ◽  
María Claudia Taleb ◽  
Magdolna Mihályi ◽  
Laura Gutierrez

Abstract Palladium was incorporated into carboxymethylated cellulose fibers as a support, thereby becoming an efficient and stable catalyst for low temperature gas phase reaction. Thus, NO was used as test molecule of Greenhouse Gas to be catalytically reduced with hydrogen on an eco-friendly sustainable material containing palladium as the active site. Prior to the catalytic test, the catalysts were reduced with glucose as an eco-friendly reagent. The material characterization was performed by SEM-EDS, XRD, LRS, TGA and FTIR.The catalytic results showed that at 170°C, NO conversion was 100% with a selectivity of 70% to nitrogen. While NOX species were completely converted into N2 at temperatures higher than 180°C. The starting commercial material Solucell® was also studied, but its performance resulted lower than the ones of functionalized fibers.The use of this strategy, i.e., the functionalization of cellulose fibers followed by in-situ formation of metallic nanoparticles, can be further applied for the design of a wide range of materials with interesting applications for gas and liquid phase reactions under mild conditions.


2014 ◽  
Vol 59 (4-5) ◽  
pp. 337-344 ◽  
Author(s):  
JiXiao WANG ◽  
Xuan WANG ◽  
QingLin GUAN ◽  
FengYing BAI ◽  
YongHeng XING ◽  
...  

Synlett ◽  
2018 ◽  
Vol 29 (07) ◽  
pp. 918-921 ◽  
Author(s):  
Issa Yavari ◽  
Zohreh Taheri ◽  
Maryam Naeimabadi ◽  
Samira Bahemmat ◽  
Mohammad Halvagar

Alkyl 2-(3-alkyl-4-oxo-2-thioxothiazolidin-5-ylidene)acetates react with hydrazonoyl chlorides in the presence of triethylamine to ­afford tetrasubstituted pyrazole derivatives. Formally, this transformation is regarded as a 1,3-dipolar cycloaddition of the exocyclic carbon–carbon double bond of the thioxothiazolidine derivatives with nitrile imines generated in situ. This efficient method provides fast access to a range of structurally diverse pyrazoles. The structure of a typical product is confirmed by X-ray crystallography.


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