scholarly journals Carbon–Heteroatom Bond Formation via Coupling Reactions Performed on a Magnetic Nanoparticle Bed

AppliedChem ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 75-88
Author(s):  
Mahmood Tajbakhsh ◽  
Ali Ramezani ◽  
Mohammad Qandalee ◽  
Mobina Falahati ◽  
Carlos J. Durán-Valle ◽  
...  

Cross-coupling reactions leading to carbon–heteroatom bonds yield compounds that attract substantial interest due to their role as structural units in many synthetic protocols for bioactive and natural products. Therefore, many research works aim at the improvement of heterogeneous catalytic protocols. We have studied the use of magnetite nanoparticles and solid base compounds in organic synthetic reactions in carbon–heteroatom bond formation because they can be flocculated and dispersed, and reversibly controlled by applying a magnetic field. In this work, we have developed an efficient and simple synthetic approach for the C–O/C–N cross-coupling reaction under ligand-free conditions by using CuI as a catalyst and KF/Fe3O4 as a base. We performed the nucleophilic aromatic substitution of electron-deficient aryl halides and phenols. It was found that both the solvent nature and the base have a profound influence on the reaction process. This approach affords good to excellent yields of arylated products. KF/Fe3O4 displayed convenient magnetic properties and could be easily separated from the reaction using a magnet and recycled several times without significant loss of catalytic activity. This method has been successfully investigated for the Ullmann coupling reaction.

2012 ◽  
Vol 8 ◽  
pp. 2004-2018 ◽  
Author(s):  
Rajendra Surasani ◽  
Dipak Kalita ◽  
A V Dhanunjaya Rao ◽  
K B Chandrasekhar

Simple and efficient procedures for palladium-catalyzed cross-coupling reactions of N-substituted 4-bromo-7-azaindole (1H-pyrrole[2,3-b]pyridine), with amides, amines, amino acid esters and phenols through C–N and C–O bond formation have been developed. The C–N cross-coupling reaction of amides, amines and amino acid esters takes place rapidly by using the combination of Xantphos, Cs2CO3, dioxane and palladium catalyst precursors Pd(OAc)2/Pd2(dba)3. The combination of Pd(OAc)2, Xantphos, K2CO3 and dioxane was found to be crucial for the C–O cross-coupling reaction. This is the first report on coupling of amides, amino acid esters and phenols with N-protected 4-bromo-7-azaindole derivatives.


Synthesis ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 4489-4499
Author(s):  
Michael Reggelin ◽  
Matthias Hempe ◽  
Lutz Schnellbächer ◽  
Tobias Wiesner

Herein, a synthetic approach using selective transition-metal-catalyzed cross-coupling reactions to thermally crosslinkable OLED materials­ based on vinyl-functionalized arylamines is reported. In a modular approach, 9,9-dialkyl-2,7-diiodo-9H-fluorene underwent a selective Ullmann cross-coupling reaction with bromo-substituted-diphenylamines to give 9,9-dialkyl-2,7-bis(bromo-substituted-diphenylamino)-9H-fluorenes that underwent end-functionalization by the Suzuki–Miyaura reaction using potassium vinyltrifluoroborate to give the corresponding 9,9-dialkyl-2,7-bis(vinyl-substituted-diphenylamino)-9H-fluorenes. Novel meta-functionalized materials were synthesized, which are difficult to prepare by traditional synthetic pathways. The thermal behavior of the compounds was investigated by DSC measurements, indicating a lower thermal sensitivity of the meta-substituted materials than their para-functionalized analogues.


Synthesis ◽  
2017 ◽  
Vol 49 (20) ◽  
pp. 4586-4598 ◽  
Author(s):  
Martyn Henry ◽  
Mohamed Mostafa ◽  
Andrew Sutherland

Amination and amidation of aryl compounds using a transition-metal-catalyzed cross-coupling reaction typically involves prefunctionalization or preoxidation of either partner. In recent years, a new class of transition-metal-catalyzed cross-dehydrogenative coupling reaction has been developed for the direct formation of aryl C–N bonds. This short review highlights the substantial progress made for ortho-C–N bond formation via transition-metal-catalyzed chelation-directed aryl C–H activation and gives an overview of the challenges that remain for directed meta- and para-selective reactions.1 Introduction2 Intramolecular C–N Cross-Dehydrogenative Coupling2.1 Nitrogen Functionality as Both Coupling Partner and Directing Group2.2 Chelating-Group-Directed Intramolecular C–N Bond Formation3 Intermolecular C–N Cross-Dehydrogenative Coupling3.1 ortho-C–N Bond Formation3.1.1 Copper-Catalyzed Reactions3.1.2 Other Transition-Metal-Catalyzed Reactions3.2 meta- and para-C–N Bond Formation4 C–N Cross-Dehydrogenative Coupling of Acidic C–H Bonds5 Conclusions


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.


2018 ◽  
Vol 16 (33) ◽  
pp. 6017-6024 ◽  
Author(s):  
Bin Sun ◽  
Shi Yin ◽  
Xiaohui Zhuang ◽  
Can Jin ◽  
Weike Su

We developed a novel metal-free method for the construction of C(sp2)–O bonds via oxidative cross-coupling reactions between various N-substituted anilines and hydroxylamine derivatives just using commercially available Selectfluor as an oxidant.


Synlett ◽  
2017 ◽  
Vol 28 (16) ◽  
pp. 2153-2156 ◽  
Author(s):  
Wen-Ting Wei ◽  
Hongze Liang ◽  
Wen-Ming Zhu ◽  
Weida Liang ◽  
Yi Wu ◽  
...  

A radical–radical cross-coupling reaction of phenols with tert-butyl nitrite has been developed with the use of water as an additive. This method allows the construction of C–N bonds under an air atmosphere at room temperature, providing the ortho-nitrated phenol derivative in moderate to good yields.


RSC Advances ◽  
2018 ◽  
Vol 8 (70) ◽  
pp. 40000-40015 ◽  
Author(s):  
Nedra Touj ◽  
Abdullah S. Al-Ayed ◽  
Mathieu Sauthier ◽  
Lamjed Mansour ◽  
Abdel Halim Harrath ◽  
...  

The in situ prepared four component system Pd(OAc)2, 1,3-dialkylbenzimidazolium halides 2a–i and 4a–i, K2CO3 under CO atmosphere catalyses carbonylative cross-coupling reaction of 2-bromopyridine with various boronic acids to yield unsymmetrical arylpyridine ketones.


RSC Advances ◽  
2015 ◽  
Vol 5 (25) ◽  
pp. 19630-19637 ◽  
Author(s):  
Shaheen M. Sarkar ◽  
Md. Lutfor Rahman ◽  
Mashitah Mohd Yusoff

Pyridinyl functionalized MCM-48-supported Pd-catalyst efficiently (0.013–0.025 mol%) promoted Heck, Suzuki and Sonogashira cross-coupling reactions. Moreover, the catalyst was reused five times without significant loss of its activity.


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