scholarly journals Sustainable Access to π-Conjugated Molecular Materials via Direct (Hetero)Arylation Reactions in Water and under Air

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3717
Author(s):  
Adiel Mauro Calascibetta ◽  
Sara Mattiello ◽  
Alessandro Sanzone ◽  
Irene Facchinetti ◽  
Mauro Sassi ◽  
...  
Keyword(s):  
Reaction Medium ◽  
Building Blocks ◽  
High Yield ◽  
Coupling Reactions ◽  
Materials Chemistry ◽  
Atom Economy ◽  
Reaction Conditions ◽  
Cross Coupling Reactions ◽  
High Boiling Point ◽  
Yield And Purity

Direct (hetero)arylation (DHA) is playing a key role in improving the efficiency and atom economy of C–C cross coupling reactions, so has impacts in pharmaceutical and materials chemistry. Current research focuses on further improving the generality, efficiency and selectivity of the method through careful tuning of the reaction conditions and the catalytic system. Comparatively fewer studies are dedicated to the replacement of the high-boiling-point organic solvents dominating the field and affecting the overall sustainability of the method. We show herein that the use of a 9:1 v/v emulsion of an aqueous Kolliphor 2 wt% solution while having toluene as the reaction medium enables the preparation of relevant examples of thiophene-containing π-conjugated building blocks in high yield and purity.

Comparison of the Suzuki cross-coupling reactions of 4,7-dichloroquinoline and 7-chloro-4-iodoquinoline with arylboronic acids using phosphine-free palladium catalysis in water

2004 ◽  
Vol 82 (2) ◽  
pp. 206-214 ◽  
Author(s):  
Richard W Friesen ◽  
Laird A Trimble
Keyword(s):  
Phenylboronic Acid ◽  
Palladium Catalysis ◽  
Suzuki Reaction ◽  
Tetrabutylammonium Bromide ◽  
Cross Coupling ◽  
Palladium Acetate ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
Arylboronic Acids ◽  
Cross Coupling Reactions

4,7-Dichloroquinoline (1a) and 7-chloro-4-iodoquinoline (1b) undergo Suzuki cross-coupling reactions with arylboronic acids catalyzed by phosphine-free palladium acetate in boiling water. Using phenylboronic acid (2), the reaction of 1a provides 7-chloro-4-phenylquinoline (3) (78%) together with diphenylquinoline (4) (12%), while 1b reacts in a much more regioselective fashion and provides 3 in 98% isolated yield. Although 1b undergoes a more regioselective Suzuki reaction than 1a, additional important observations are that the overall reaction of 1b with 2 is three times slower than 1a and that the reaction occurs in the absence of tetrabutylammonium bromide. Using optimized reaction conditions, a variety of aryl and vinylboronic acids undergo regioselective Suzuki cross-coupling with 1b to provide the products 7, 10, and 11 in good to excellent yield.Key words: palladium, cross-coupling, regioselectivity, quinolines, boronic acids.

Heterogeneous Metal Catalysis for the Environmentally Benign Synthesis of Medicinally Important Scaffolds, Intermediates, and Building Blocks

2021 ◽  
Vol 25 ◽  
Author(s):  
Maysa Ilamanova ◽  
Maxim Mastyugin ◽  
Christian Schäfer ◽  
Anne Kokel ◽  
Béla Török
Keyword(s):  
Building Blocks ◽  
Metal Catalysts ◽  
Solid Metal ◽  
Coupling Reactions ◽  
Hydrogenation Catalysts ◽  
Metal Catalysis ◽  
Solid Catalysts ◽  
Cross Coupling Reactions ◽  
Benign Synthesis ◽  
Two Sides

: This account provides a broad overview of the application of solid metal catalysts in synthetic chemistry with a focus on the synthesis of medicinally important scaffolds or building blocks. Heterogeneous catalysis is a fundamental contributor to green or sustainable synthesis. Despite this, many synthetic chemists overwhelmingly focus on homogeneous methods, and due to their unfamiliarity with solid catalysts, many would not consider using them. The primary purpose of this work is to bring solid catalysts and their application possibilities to the attention of synthetic chemists in a format that focuses on reactions, thus building a bridge between the two sides for the benefit of sustainable applications and, eventually, the whole society. The two major parts of this account describe the common types of solid metal catalysts and the applications of these catalysts in sustainable synthesis. The first part gives an overview of the major types of solid metal catalysts, including common hydrogenation catalysts to metal nanoparticles. The second and more extensive part illustrates the use of these catalysts in a thematic order based on reaction types, including hydrogenation, hydrogenolysis, oxidation, metathesis, cross-coupling reactions, and hydroformylation.

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.

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.

A novel and efficient zinc-catalyzed thioetherification of aryl halides

RSC Advances ◽  
2015 ◽  
Vol 5 (41) ◽  
pp. 32675-32678 ◽  
Author(s):  
Amrutha P. Thankachan ◽  
K. S. Sindhu ◽  
K. Keerthi Krishnan ◽  
Gopinathan Anilkumar
Keyword(s):  
Cross Coupling ◽  
Aryl Halides ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
Cross Coupling Reactions

The first Zn-catalyzed protocol for C–S cross-coupling reactions for the synthesis of substituted aryl and alkyl sulfides with good yields under mild reaction conditions is described.

Copper-catalyzed synthesis of 2-aminophenyl benzothiazoles: a novel approach

2018 ◽  
Vol 16 (37) ◽  
pp. 8267-8272 ◽  
Author(s):  
S. N. Murthy Boddapati ◽  
Chandra Mohan Kurmarayuni ◽  
Baby Ramana Mutchu ◽  
Ramana Tamminana ◽  
Hari Babu Bollikolla
Keyword(s):  
Nucleophilic Substitution ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
Moderate Reaction ◽  
Cross Coupling Reactions ◽  
Novel Approach

Substituted 2-aminophenyl benzothiazoles have been constructed from thiourea via copper-catalyzed desulfurization/nucleophilic substitution followed by domino intra- and intermolecular C–N cross-coupling reactions under moderate reaction conditions.

Expanded radialenes: Modular synthesis and properties of cross-conjugated enyne macrocycles

2008 ◽  
Vol 80 (3) ◽  
pp. 621-637 ◽  
Author(s):  
Rik R. Tykwinski ◽  
Mojtaba Gholami ◽  
Sara Eisler ◽  
Yuming Zhao ◽  
Frederic Melin ◽  
...  
Keyword(s):  
Cross Coupling ◽  
Building Blocks ◽  
Coupling Reactions ◽  
New Class ◽  
Modular Synthesis ◽  
The Past ◽  
Cross Coupling Reactions ◽  
Conjugated Macrocycles ◽  
Block Approach

During the past two decades, shape-persistent conjugated macrocycles with a broad spectrum of attributes and topologies have been synthesized. This includes macrocycles with remarkable electronic, optical, and supramolecular properties, as well as intriguing frameworks. Expanded radialenes are a class of conjugated shape-persistent macrocycles that arise from the formal insertion of acetylene units into a radialene framework. A related class of macrocycles, the expanded radiaannulenes, contains both endo- and exocyclic vinylene and vinylidene segments, respectively, and accordingly exhibits properties intermediate between radialenes and annulenes. Enyne building blocks have been developed that are suitable for forming a macrocyclic framework through a step-wise sequence of Pd-catalyzed cross-coupling reactions. This "building-block" approach allows us to explore a range of molecular architectures that will ultimately provide for an understanding of π-delocalization in these compounds. The synthesis and structural characterization of the first members of this new class of expanded radialenes and radiaannulenes are described.

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