scholarly journals Modified ultradispersed diamonds based catalytic systems in cross-coupling reactions

Author(s):  
A. A. Lugovski ◽  
G. A. Gusakov ◽  
M. P. Samtsov ◽  
V. A. Parhomenko ◽  
S. V. Adamchyk

Methods for preparation of nanocomposites of modified detonation nanodiamonds (DND) with metallic palladium have been developed and their catalytic activity in the Suzuki-Miyaura cross-coupling reaction in various reaction media has been studied. Methods for the regeneration of palladium-containing nanocomposites from the reaction mixture have been developed. The high catalytic activity of nanocomposites is confirmed by kinetic analysis based on the results of chromatographic analysis of the reaction mixture and is comparable to the literature data about similar catalytic systems. Regenerated nanocomposites showed the retention of catalytic activity for 3 consecutive cross-coupling cycles on model systems.

Author(s):  
Aleksandr Pestov ◽  
Aleksandr Mekhaev ◽  
Yuliya Privar ◽  
Natalya Prokuda ◽  
Evgeniy Modin ◽  
...  

Here, we report the results of screening of the catalytic activity of Pd-containing chitosan beads and cryogels in the cross-coupling reaction, hydrogenation of alkenes, nitro-, and carbonyl compounds and the hydrodechlorination of chlorophenols. Pd0-containing chitosan beads and cryogels show moderate catalytic activity in the reduction of alkenes and nitroaromatics. The conversion of nitroaromatics decreases for substrates with electron-withdrawing substituents, while the conversion of alkenes increases with the activation of carbon-carbon double bonds. For several substrates, a significant difference in kinetics and conversion degrees was observed for Pd nanoparticles supported on chitosan beads and cryogels. It was found that conversion in the hydrodechlorination reaction depends on substrate structure, being higher for substrates containing substituents with a positive mesomeric effect. Pd2+-chitosan catalysts showed high catalytic activity in cross-coupling (Heck reaction) offering the following advantages over known catalytic systems: lower reaction temperature, the selective functionalisation of C-I bonds, and the possibility to perform reactions with iodobenzene without base addition.


Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1788
Author(s):  
S. N. Murthy Boddapati ◽  
Ramana Tamminana ◽  
Ravi Kumar Gollapudi ◽  
Sharmila Nurbasha ◽  
Mohamed E. Assal ◽  
...  

A facile, one-pot, and proficient method was developed for the production of various 2-arylaminobenzimidazoles. This methodology is based for the first time on a copper catalyst promoted domino C–N cross-coupling reaction for the generation of 2-arylaminobenzimidazoles. Mechanistic investigations revealed that the synthetic pathway involves a copper-based desulphurization/nucleophilic substitution and a subsequent domino intra and intermolecular C–N cross-coupling reactions. Some of the issues typically encountered during the synthesis of 2-arylaminobezimidazoles, including the use of expensive catalytic systems and the low reactivity of bromo precursors, were addressed using this newly developed copper-catalyzed method. The reaction procedure is simple, generally with excellent substrate tolerance, and provides good to high yields of the desired products.


RSC Advances ◽  
2015 ◽  
Vol 5 (89) ◽  
pp. 72453-72457 ◽  
Author(s):  
Raju Kumar Borah ◽  
Hirak Jyoti Saikia ◽  
Abhijit Mahanta ◽  
Vijay Kumar Das ◽  
Utpal Bora ◽  
...  

A green and efficient method for the synthesis of PEG supported Pd-NPs has been developed using aqueous extract of C. esculanta leaf. The prepared NPs show excellent catalytic activity for Suzuki–Miyaura cross-coupling reaction at room temperature.


RSC Advances ◽  
2021 ◽  
Vol 11 (56) ◽  
pp. 35311-35320
Author(s):  
Katsuya Kaikake ◽  
Naoki Jou ◽  
Go Shitara ◽  
Ren-Hua Jin

Bis-theophylline-palladium complex exhibit high catalytic activity in the C–C coupling reaction with excellent recyclability in the presence of NaCl.


2020 ◽  
Author(s):  
Chet Tyrol ◽  
Nang Yone ◽  
Connor Gallin ◽  
Jeffery Byers

By using an iron-based catalyst, access to enantioenriched 1,1-diarylakanes was enabled through an enantioselective Suzuki-Miyaura crosscoupling reaction. The combination of a chiral cyanobis(oxazoline) ligand framework and 1,3,5-trimethoxybenzene additive were essential to afford high yields and enantioselectivities in cross-coupling reactions between unactivated aryl boronic esters and a variety of benzylic chlorides, including challenging ortho-substituted benzylic chloride substrates. Mechanistic investigations implicate a stereoconvergent pathway involving carbon-centered radical intermediates.


Author(s):  
Jonathon Moir

Pharmaceuticals and drugs have become an indispensable part of human life. Presently, a myriad of different drugs are available for a variety of mental and physical health concersn. The synthesis of these drugs, however, remains an elusive and often difficult aspect of the industry. The importance of chirality, or "handedness", in the synthesis of natural products is paramount, as any given pair of enantiomers can have widely differing physiological effects. As such, the ability to control the enantioselectivity of a reaction is of the utmost importance. One example of a facile method used to form carbon-carbon bonds is the Suzuki-Miyaura cross-coupling reaction. Not only is this reaction effective at coupling primary organoboronic esters with organohalides, but recent work in the Crudden group in the Department of Chemistry has revealed an effective method of also cross-couplingchiral secondary organoboronic esters with good retention of stereochemistry. This work, the first of its kind, is crucial in developing single-handed natural products for a wide array of applications, including applications in the pharmaceutical industry. The end result is safer and more effective drugs for distribution to the general public. To expand the scope of this project, new substrates are currently being synthesized for cross-coupling applications. The overall goal is to improve upon current methodologies, while helping to meet the industrial and academic needs of the future.  


Synthesis ◽  
2020 ◽  
Vol 52 (16) ◽  
pp. 2387-2394 ◽  
Author(s):  
Jorge A. Cabezas ◽  
Natasha Ferllini

A regiospecific palladium-catalyzed cross-coupling reaction using the operational equivalent of the dianion 1,3-dilithiopropyne, with aromatic iodides is reported. This reaction gives high yields of 1-propyn-1-yl-benzenes and 2-(propyn-1-yl)thiophenes in the presence of catalytic amounts of palladium(0) or (II) and stoichiometric amounts of copper iodide. No terminal alkyne or allene isomers were detected. Reaction conditions were very mild and several functional groups were tolerated.


Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 652 ◽  
Author(s):  
Monika Olesiejuk ◽  
Agnieszka Kudelko ◽  
Marcin Swiatkowski ◽  
Rafal Kruszynski

New derivatives of 4-alkyl-3,5-diaryl-4H-1,2,4-triazole were synthesized utilizing the Suzuki cross-coupling reaction. The presented methodology comprises of the preparation of bromine-containing 4-alkyl-4H-1,2,4-triazoles and their coupling with different commercially available boronic acids in the presence of ionic liquids or in conventional solvents. The obtained compounds were tested for their luminescence properties.


RSC Advances ◽  
2014 ◽  
Vol 4 (69) ◽  
pp. 36437-36443 ◽  
Author(s):  
Zhenhong Guan ◽  
Buyi Li ◽  
Guoliang Hai ◽  
Xinjia Yang ◽  
Tao Li ◽  
...  

Microporous polymers with built-in triphenylphosphine palladium exhibit highly efficient catalytic activity for cross-coupling reactions of benzyl chloride under mild conditions.


2017 ◽  
Vol 15 (27) ◽  
pp. 5805-5810 ◽  
Author(s):  
Yan Liu ◽  
Jia Yuan ◽  
Zi-Fei Wang ◽  
Si-Hao Zeng ◽  
Meng-Yue Gao ◽  
...  

An efficient solvent-free and aqueous protocol for the Buchwald–Hartwig cross-coupling reaction has been developed. Notably, the catalytic system also efficiently catalyzed the reaction under aqueous conditions.


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