scholarly journals Preparation of Metal-Immobilized Methacrylate-Based Monolithic Columns for Flow-Through Cross-Coupling Reactions

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7346
Author(s):  
Akhmad Sabarudin ◽  
Shin Shu ◽  
Kazuhiro Yamamoto ◽  
Tomonari Umemura
Keyword(s):  
Cross Coupling ◽  
Iminodiacetic Acid ◽  
Monolithic Columns ◽  
Coupling Reactions ◽  
Nickel Iron ◽  
Chemically Modified ◽  
Cross Coupling Reactions ◽  
Ethylene Dimethacrylate ◽  
Flow Through ◽  
Inner Diameter

With the aim of developing efficient flow-through microreactors for high-throughput organic synthesis, in this work, microreactors were fabricated by chemically immobilizing palladium-, nickel-, iron-, and copper-based catalysts onto ligand-modified poly(glycidyl methacrylate-co-ethylene dimethacrylate) [poly(GMA-co-EDMA)] monoliths, which were prepared inside a silicosteel tubing (10 cm long with an inner diameter of 1.0 mm) and modified with several ligands including 5-amino-1,10-phenanthroline (APHEN), iminodiacetic acid (IDA), and iminodimethyl phosphonic acid (IDP). The performance of the resulting microreactors in Suzuki−Miyaura cross-coupling reactions was evaluated, finding that the poly(GMA-co-EDMA) monolith chemically modified with 5-amino-1,10-phenanthroline as a binding site for the palladium catalyst provided an excellent flow-through performance, enabling highly efficient and rapid reactions with high product yields. Moreover, this monolithic microreactor maintained its good activity and efficiency during prolonged use.

PolyHIPE Supports in Batch and Flow-Through Suzuki Cross-Coupling Reactions

2005 ◽  
Vol 44 (23) ◽  
pp. 8565-8572 ◽  
Author(s):  
Jane F. Brown ◽  
Peter Krajnc ◽  
Neil R. Cameron
Keyword(s):  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Flow Through

Chromium-Catalyzed Cross-Coupling Reactions by Selective Activation of Chemically Inert Aromatic C−O, C−N and C−H Bonds

Synlett ◽  
2021 ◽  
Author(s):  
Xuefeng Cong ◽  
Xiaoming Zeng
Keyword(s):  
Precious Metals ◽  
Cross Coupling ◽  
High Spin State ◽  
Cost Effective ◽  
Coupling Reactions ◽  
Nickel Iron ◽  
Effective Strategies ◽  
Cross Coupling Reactions ◽  
Earth Abundant ◽  
Metal Catalyzed

Transition-metal-catalyzed cross-coupling has appeared as one of powerful and useful tools in the formation of C–C and C–heteroatom bonds. Given that the resource of precious metals on earth is shortage, the use of earth-abundant metals as catalysts in developing cost-effective strategies of cross-coupling is one of trends to synthetic chemistry. Compared with the achievements using first-row metal catalysis of nickel, iron, cobalt, and even manganese, the group 6 metal chromium has rarely been used in promoting cross-coupling. This perspective will cover recent advances in Cr-catalyzed cross-coupling reactions by the transformations of chemically inert C(aryl)–O, C(aryl)–N and C(aryl)–H bonds, offering selective strategies for molecule construction. The ability of low-valent Cr with a high-spin state involving in the process of two-electron oxidative addition will be highlighted, which is different with the mechanism by single-electron-transfer that is traditionally proposed in chromium-mediated transformations. 1 Introduction 2 Cr-Catalyzed Kumada Coupling of Unactivated C(aryl)−O and C(aryl)−N Bonds 3 Cr-Catalyzed Reductive Cross-Coupling between Two Unactivated C(aryl)–Heteroatom Bonds 4 Cr-Catalyzed Functionalization of Unactivated C(aryl)–H Bonds 5 Conclusion and Outlook

Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian
Keyword(s):  
Functional Group ◽  
Low Cost ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phenol Derivatives ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
One Step ◽  
Aryl Tosylates ◽  
Low Sensitivity

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.

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.

Phosphino-Triazole Ligands for Palladium-Catalysed Cross-Coupling

2018 ◽  
Author(s):  
Yiming Zhao ◽  
Huy van Nguyen ◽  
Louise Male ◽  
Philip Craven ◽  
Benjamin R. Buckley ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Cross Coupling ◽  
Product Formation ◽  
Coupling Reactions ◽  
Volume Determination ◽  
Online Tool ◽  
Triazole Derivatives ◽  
Cross Coupling Reactions ◽  
Modelling Approaches

<div>Twelve 1,5-disubtituted and fourteen 5-substituted 1,2,3-triazole derivatives bearing diaryl or dialkyl phosphines at the 5-position were synthesised and used as ligands for palladium-catalysed Suzuki-Miyaura cross-coupling reactions. Bulky substrates were tested, and lead-like product formation was demonstrated. The online tool SambVca 2.0 was used to assess steric parameters of ligands and preliminary buried volume determination using XRD obtained data in a small number of cases proved to be informative. Two modelling approaches were compared for the determination of</div><div>the buried volume of ligands where XRD data was not available. An approach with imposed steric restrictions was found to be superior in leading to buried volume determinations that closely correlate with observed reaction conversions. The online tool LLAMA was used to determine lead-likeness of potential Suzuki-Miyaura cross-coupling products, from which ten of the most lead-like were successfully synthesised. Thus, confirming these readily accessible triazole-containing phosphines as highly suitable ligands for reaction screening and optimisation in drug discovery campaigns.</div>

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