scholarly journals Facile Synthesis of 5-aryl-N-(pyrazin-2-yl)thiophene-2-carboxamides via Suzuki Cross-Coupling Reactions, Their Electronic and Nonlinear Optical Properties through DFT Calculations

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7309
Author(s):  
Gulraiz Ahmad ◽  
Nasir Rasool ◽  
Adeel Mubarik ◽  
Ameer Fawad Zahoor ◽  
Muhammad Ali Hashmi ◽  
...  
Keyword(s):  
Energy Gap ◽  
Chemical Shifts ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Intermediate Compound ◽  
Chemical Hardness ◽  
Coupling Reactions ◽  
Lumo Energy ◽  
Cross Coupling Reactions ◽  
Homo Lumo

Synthesis of 5-aryl-N-(pyrazin-2-yl)thiophene-2-carboxamides (4a–4n) by a Suzuki cross-coupling reaction of 5-bromo-N-(pyrazin-2-yl)thiophene-2-carboxamide (3) with various aryl/heteroaryl boronic acids/pinacol esters was observed in this article. The intermediate compound 3 was prepared by condensation of pyrazin-2-amine (1) with 5-bromothiophene-2-carboxylic acid (2) mediated by TiCl4. The target pyrazine analogs (4a–4n) were confirmed by NMR and mass spectrometry. In DFT calculation of target molecules, several reactivity parameters like FMOs (EHOMO, ELUMO), HOMO–LUMO energy gap, electron affinity (A), ionization energy (I), electrophilicity index (ω), chemical softness (σ) and chemical hardness (η) were considered and discussed. Effect of various substituents was observed on values of the HOMO–LUMO energy gap and hyperpolarizability. The p-electronic delocalization extended over pyrazine, benzene and thiophene was examined in studying the NLO behavior. The chemical shifts of 1H NMR of all the synthesized compounds 4a–4n were calculated and compared with the experimental values.

scholarly journals Palladium(0) Catalyzed Synthesis of (E)-4-Bromo-N-((3-bromothiophen-2-yl)methylene)-2-methylaniline Derivatives via Suzuki Cross-Coupling Reaction: An Exploration of Their Non-Linear Optical Properties, Reactivity and Structural Features

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5605
Author(s):  
Komal Rizwan ◽  
Nasir Rasool ◽  
Muhammad Ali Hashmi ◽  
Sadia Noreen ◽  
Muhammad Zubair ◽  
...  
Keyword(s):  
Density Functional ◽  
Structural Characteristics ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Structural Features ◽  
Chemical Hardness ◽  
Coupling Reactions ◽  
Reactivity Descriptors ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction

A series of (E)-4-bromo-N-((3-bromothiophen-2-yl)methylene)-2-methylaniline analogs synthesized in considerable yields through Suzuki cross-coupling reactions. Various electron donating and withdrawing functional moieties were successfully incorporated under the employed reaction conditions. Reaction of 4-bromo-2-methylaniline (1) with 3-bromothiophene-2-carbaldehyde (2b) in the existence of glacial acetic acid, provided (E)-4-bromo-N-((3-bromothiophen-2-yl)methylene)-2-methylaniline (3b) in excellent yield (94%). Suzuki coupling of 3b with different boronic acids in the presence of Pd(PPh3)4/K3PO4 at 90 °C led to the synthesis of the monosubstituted and bisubstituted products 5a–5d and 6a–6d in moderate yields (33–40% and 31–46%, respectively). Density functional theory (DFT) investigations were performed on different synthesized analogues 5a–5d, 6a–6d to determine their structural characteristics. The calculations provide insight into the frontier molecular orbitals (FMOs) of the imine-based analogues and their molecular electrostatic potential (MESP). Reactivity descriptors like ionization energy (I), electron affinity (A), chemical hardness (ƞ) and index of nucleophilicity have been calculated for the first time for the synthesized molecules.

An Iron-Based Catalyst Enables The Enantioconvergent Synthesis of Chiral 1,1-Diarylalkanes Through a Suzuki-Miyaura Cross-Coupling Reaction

2020 ◽  
Author(s):  
Chet Tyrol ◽  
Nang Yone ◽  
Connor Gallin ◽  
Jeffery Byers
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Radical Intermediates ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Boronic Esters ◽  
Carbon Centered Radical ◽  
Iron Based ◽  
High Yields

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.

Selectfluor-induced C(sp2)–O coupling reaction of N-substituted anilines with hydroxylamine derivatives

2018 ◽  
Vol 16 (33) ◽  
pp. 6017-6024 ◽  
Author(s):  
Bin Sun ◽  
Shi Yin ◽  
Xiaohui Zhuang ◽  
Can Jin ◽  
Weike Su
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Substituted Anilines ◽  
Metal Free ◽  
Cross Coupling Reactions ◽  
Hydroxylamine Derivatives

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.

scholarly journals Synthesis of 9-arylalkynyl- and 9-aryl-substituted benzo[b]quinolizinium derivatives by Palladium-mediated cross-coupling reactions

2018 ◽  
Vol 14 ◽  
pp. 1871-1884 ◽  
Author(s):  
Siva Sankar Murthy Bandaru ◽  
Darinka Dzubiel ◽  
Heiko Ihmels ◽  
Mohebodin Karbasiyoun ◽  
Mohamed M A Mahmoud ◽  
...  
Keyword(s):  
Emission Intensity ◽  
Binding Constants ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Sonogashira Coupling ◽  
Reaction Conditions ◽  
Quadruplex Dna ◽  
Cross Coupling Reactions ◽  
Sonogashira Coupling Reaction

9-Arylbenzo[b]quinolizinium derivatives were prepared with base-free Suzuki–Miyaura coupling reactions between benzo[b]quinolizinium-9-trifluoroborate and selected benzenediazonium salts. In addition, the Sonogashira coupling reaction between 9-iodobenzo[b]quinolizinium and the arylalkyne derivatives yielded four novel 9-(arylethynyl)benzo[b]quinolizinium derivatives under relatively mild reaction conditions. The 9-(N,N-dimethylaminophenylethynyl)benzo[b]quinolizinium is only very weakly emitting, but the emission intensity increases by a factor >200 upon protonation, so that this derivative may operate as pH-sensitive light-up probe. Photometric and fluorimetric titrations of duplex and quadruplex DNA to 9-(arylethynyl)benzo[b]quinolizinium derivatives revealed a significant binding affinity of these compounds towards both DNA forms with binding constants ofKb= 0.2–2.2 × 105M−1.

The Synthesis of Pharmaceuticals: The Effective Application of Secondary Boronic Esters in Enantioselective Suzuki ‐ Miyaura Cross ‐ Coupling Reactions

2016 ◽  
Author(s):  
Jonathon Moir
Keyword(s):  
Natural Products ◽  
Human Life ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Boronic Esters ◽  
Carbon Carbon Bonds ◽  
Effective Drugs

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.  

Regiospecific Palladium-Catalyzed Cross-Coupling Reactions Using the Operational Equivalent of 1,3-Dilithiopropyne

Synthesis ◽  
2020 ◽  
Vol 52 (16) ◽  
pp. 2387-2394 ◽  
Author(s):  
Jorge A. Cabezas ◽  
Natasha Ferllini
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Terminal Alkyne ◽  
Copper Iodide ◽  
Reaction Conditions ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed ◽  
High Yields

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.

scholarly journals Synthesis of 4-Alkyl-4H-1,2,4-triazole Derivatives by Suzuki Cross-coupling Reactions and Their Luminescence Properties

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 652 ◽  
Author(s):  
Monika Olesiejuk ◽  
Agnieszka Kudelko ◽  
Marcin Swiatkowski ◽  
Rafal Kruszynski
Keyword(s):  
Ionic Liquids ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Boronic Acids ◽  
Luminescence Properties ◽  
Coupling Reactions ◽  
Triazole Derivatives ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Derivatives Of

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.

A highly efficient catalyst for Suzuki–Miyaura coupling reaction of benzyl chloride under mild conditions

RSC Advances ◽  
2014 ◽  
Vol 4 (69) ◽  
pp. 36437-36443 ◽  
Author(s):  
Zhenhong Guan ◽  
Buyi Li ◽  
Guoliang Hai ◽  
Xinjia Yang ◽  
Tao Li ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Benzyl Chloride ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Efficient Catalyst ◽  
Microporous Polymers ◽  
Mild Conditions ◽  
Highly Efficient ◽  
Cross Coupling Reactions

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

scholarly journals Harnessing C–O Bonds in Stereoselective Cross-Coupling and Cross-Electrophile Coupling Reactions

Synlett ◽  
2020 ◽  
Author(s):  
Elizabeth R. Jarvo ◽  
Amberly B. Sanford
Keyword(s):  
Bioactive Compounds ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Secondary Alcohols ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Stereogenic Centers

AbstractWe discuss our laboratory’s research in the activation of alcohol derivatives in cross-coupling and cross-electrophile coupling reactions. Our developed methods enable the use of secondary alcohols to afford tertiary stereogenic centers, which we applied to the synthesis of pharmaceutically relevant compounds and substructures. We first ­discuss the synthesis of bioactive compounds through stereospecific Kumada cross-coupling reactions and follow this with a discussion on the development of our stereoselective cross-electrophile coupling ­reaction to synthesize cyclopropanes.1 Introduction2 Cross-Coupling Reactions3 Cross-Electrophile Coupling Reactions4 Conclusion

Application of a 2-aryl indenylphosphine ligand in the Buchwald–Hartwig cross-coupling reactions of aryl and heteroaryl chlorides under the solvent-free and aqueous conditions

2017 ◽  
Vol 15 (27) ◽  
pp. 5805-5810 ◽  
Author(s):  
Yan Liu ◽  
Jia Yuan ◽  
Zi-Fei Wang ◽  
Si-Hao Zeng ◽  
Meng-Yue Gao ◽  
...  
Keyword(s):  
Catalytic System ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Solvent Free ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Aqueous Conditions

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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