scholarly journals N -Methylcaprolactam as a Dipolar Aprotic Solvent for Iron-Catalyzed Cross-Coupling Reactions: Matching Efficiency with Safer Reaction Media

ChemCatChem ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 1196-1199 ◽  
Author(s):  
Elwira Bisz ◽  
Pamela Podchorodecka ◽  
Michal Szostak
Keyword(s):  
Aprotic Solvent ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Dipolar Aprotic Solvent ◽  
Cross Coupling Reactions ◽  
Matching Efficiency ◽  
Reaction Media

3D Printed Tetrakis(triphenylphosphine)palladium (0) Impregnated Stirrer Devices for Suzuki-Miyaura Cross-Coupling Reactions

2020 ◽  
Author(s):  
Matthew Penny ◽  
Zenobia Rao ◽  
Ahtsham Ishaq ◽  
Rumintha Thavarajah ◽  
Stephen Hilton
Keyword(s):  
Cross Coupling ◽  
Coupling Reactions ◽  
Simple Modification ◽  
Cross Coupling Reactions ◽  
Multiple Reactions ◽  
3D Printed ◽  
Low Levels ◽  
Printed Materials ◽  
Reaction Media ◽  
Biaryl Compounds

3D printed materials can be readily modified to create bespoke structures that incorporate a range of catalysts at the point of printing. In this present study we report on the design and 3D printing of tetrakis (triphenylphosphine) palladium (0) impregnated 3D printed stirrer devices that were used to catalyze a Suzuki-Miyaura reaction between biaryl compounds in a batch-based approach. It was shown that the devices themselves are reusable, easy to use, air-stable, give access to an array of biaryl compounds in excellent yields and lead to low levels of palladium loss into the reaction. Simple modification of the device’s design by size reduction, meant that they could also be used to reduce the time of the Suzuki-Miyaura reaction by microwave enhanced heating. At the end of the reaction, devices can simply be removed from the flask, washed and reused, analogous to stirrer bead workflows. This makes the overall process of setting up multiple reactions simpler by obviating the need to weigh out catalysts for reactions and the device, once used, can be simply removed from the reaction media at the end of the reaction.

scholarly journals 3D Printed Tetrakis(triphenylphosphine)palladium (0) Impregnated Stirrer Devices for Suzuki-Miyaura Cross-Coupling Reactions

2020 ◽  
Author(s):  
Matthew Penny ◽  
Zenobia Rao ◽  
Ahtsham Ishaq ◽  
Rumintha Thavarajah ◽  
Stephen Hilton
Keyword(s):  
Cross Coupling ◽  
Coupling Reactions ◽  
Simple Modification ◽  
Cross Coupling Reactions ◽  
Multiple Reactions ◽  
3D Printed ◽  
Low Levels ◽  
Printed Materials ◽  
Reaction Media ◽  
Biaryl Compounds

3D printed materials can be readily modified to create bespoke structures that incorporate a range of catalysts at the point of printing. In this present study we report on the design and 3D printing of tetrakis (triphenylphosphine) palladium (0) impregnated 3D printed stirrer devices that were used to catalyze a Suzuki-Miyaura reaction between biaryl compounds in a batch-based approach. It was shown that the devices themselves are reusable, easy to use, air-stable, give access to an array of biaryl compounds in excellent yields and lead to low levels of palladium loss into the reaction. Simple modification of the device’s design by size reduction, meant that they could also be used to reduce the time of the Suzuki-Miyaura reaction by microwave enhanced heating. At the end of the reaction, devices can simply be removed from the flask, washed and reused, analogous to stirrer bead workflows. This makes the overall process of setting up multiple reactions simpler by obviating the need to weigh out catalysts for reactions and the device, once used, can be simply removed from the reaction media at the end of the reaction.

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>

A Revised Modular Approach to D8-THC and Derivatives Through Late-Stage Suzuki-Miyaura Cross-Coupling Reactions

2019 ◽  
Author(s):  
Victor Bloemendal ◽  
Floris P. J. T. Rutjes ◽  
Thomas J. Boltje ◽  
Daan Sondag ◽  
Hidde Elferink ◽  
...  
Keyword(s):  
Biological Activity ◽  
Late Stage ◽  
Medicinal Chemistry ◽  
Cross Coupling ◽  
Modular Approach ◽  
Coupling Reactions ◽  
One Pot ◽  
Biologically Relevant ◽  
Cross Coupling Reactions ◽  
Chemistry Research

<p>In this manuscript we describe a modular pathway to synthesize biologically relevant (–)-<i>trans</i>-Δ<sup>8</sup>-THC derivatives, which can be used to modulate the pharmacologically important CB<sub>1</sub> and CB<sub>2</sub> receptors. This pathway involves a one-pot Friedel-Crafts alkylation/cyclization protocol, followed by Suzuki-Miyaura cross-coupling reactions and gives rise to a series of new Δ<sup>8</sup>-THC derivatives. In addition, we demonstrate using extensive NMR evidence that similar halide-substituted Friedel-Crafts alkylation/cyclization products in previous articles were wrongly assigned as the para-isomers, which also has consequence for the assignment of the subsequent cross-coupled products and interpretation of their biological activity. </p> <p>Considering the importance of the availability of THC derivatives in medicinal chemistry research and the fact that previously synthesized compounds were wrongly assigned, we feel this research is describing a straightforward pathway into new cannabinoids.</p>

Carbon-Heteroatom Cross-Coupling via an Electronically Excited Nickel (II) Complex

2019 ◽  
Author(s):  
Randolph Escobar ◽  
Jeffrey Johannes
Keyword(s):  
Energy Transfer ◽  
Functional Groups ◽  
Cross Coupling ◽  
Reductive Elimination ◽  
Aryl Halides ◽  
Coupling Reactions ◽  
General Methodology ◽  
Cross Coupling Reactions ◽  
Electronically Excited ◽  
Energy Transfer Pathway

<div>While carbon-heteroatom cross coupling reactions have been extensively studied, many methods are specific and</div><div>limited to a set of substrates or functional groups. Reported here is a method that allows for C-O, C-N and C-S cross coupling reactions under one general methodology. We propose that an energy transfer pathway, in which an iridium photosensitizer produces an excited nickel (II) complex, is responsible for the key reductive elimination step that couples aryl halides to 1° and 2° alcohols, anilines, thiophenols, carbamates and sulfonamides.</div>

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