scholarly journals Nickel-Catalyzed Ipso-Borylation of Silyloxyarenes via C–O Bond Activation

2021 ◽  
Author(s):  
Wesley Pein ◽  
Eric Wiensch ◽  
John Montgomery
Keyword(s):  
Bond Activation ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Nickel Catalysis ◽  
Silyl Ethers ◽  
Cross Coupling Reactions ◽  
Boronic Esters ◽  
Directing Group ◽  
Aromatic Systems ◽  
Oxygen Bond

A mild method to convert silyloxyarenes to pinacol boronic esters using nickel catalysis is described. In contrast to other borylation protocols of relatively inert C–O bonds, the method is competent in activating the carbon-oxygen bond of silyloxyarenes in isolated aromatic systems lacking a directing group. The catalytic functionalization of benzyl silyl ethers was also achieved under these conditions. Orthogonal reactivity of silyloxyarenes vs other electrophiles was demonstrated in the case of several cross-coupling reactions wherein the unaffected silyloxarene could be functionalized subsequently.

scholarly journals Nickel-Catalyzed Ipso-Borylation of Silyloxyarenes via C–O Bond Activation

2021 ◽  
Author(s):  
Wesley Pein ◽  
Eric Wiensch ◽  
John Montgomery
Keyword(s):  
Bond Activation ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Nickel Catalysis ◽  
Silyl Ethers ◽  
Cross Coupling Reactions ◽  
Boronic Esters ◽  
Directing Group ◽  
Aromatic Systems ◽  
Oxygen Bond

A mild method to convert silyloxyarenes to pinacol boronic esters using nickel catalysis is described. In contrast to other borylation protocols of relatively inert C–O bonds, the method is competent in activating the carbon-oxygen bond of silyloxyarenes in isolated aromatic systems lacking a directing group. The catalytic functionalization of benzyl silyl ethers was also achieved under these conditions. Orthogonal reactivity of silyloxyarenes vs other electrophiles was demonstrated in the case of several cross-coupling reactions wherein the unaffected silyloxarene could be functionalized subsequently.

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.

scholarly journals DFT Study of Unstrained Ketone C-C Bond Activation via Rhodium(I)-Catalyzed Suzuki-Miyaura Cross-Coupling Reactions

2019 ◽  
Author(s):  
Dengmengfei Xiao ◽  
Lili Zhao ◽  
Diego Andrada
Keyword(s):  
Density Functional ◽  
Bond Activation ◽  
Chemical Reactivity ◽  
Cross Coupling ◽  
Underlying Mechanism ◽  
Reductive Elimination ◽  
Coupling Reactions ◽  
Co Catalysts ◽  
Cross Coupling Reactions ◽  
Strain Model

Unstrained cyclic ketones can participate in cooperative Suzuki-Miyaura cross-coupling type reaction using rhodium(I)-based catalyst via C-C bond activation. The regioselectivity indicates a trend where the most substituted side is activated and it is controlled by the beta-substituents. In this work, Density Functional Theory (DFT) calculations have been carried out to disclose the underlying mechanism in the reaction of a ketone series and arylboronate using ylidene as ancillary ligand and pyridine as co-catalysts. The computed energies suggest the reductive elimination step with the highest energy while the reductive elimination has the highest energy barrier. By the means of the Activation Strain Model (ASM) of chemical reactivity, it is found that the ketone strain energy released on the oxidative addition does not control the relativity of the OA reactivity, but indeed is the interaction energy between Rh(I) and C-C bond the ruling effect. The effect of the beta-substituents on regioselectivity has been additionally studied.

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.  

ChemInform Abstract: Copper-Catalyzed Cross-Coupling Reactions of Epoxides with gem-Diborylmethane: Access to γ-Hydroxyl Boronic Esters.

ChemInform ◽  
2016 ◽  
Vol 47 (31) ◽  
Author(s):  
Ahmed Ebrahim-Alkhalil ◽  
Zhen-Qi Zhang ◽  
Tian-Jun Gong ◽  
Wei Su ◽  
Xiao-Yu Lu ◽  
...  
Keyword(s):  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Boronic Esters

scholarly journals Primary alkyl bis-catecholato silicates in dual photoredox/nickel catalysis: aryl- and heteroaryl-alkyl cross coupling reactions

2016 ◽  
Vol 3 (4) ◽  
pp. 462-465 ◽  
Author(s):  
Christophe Lévêque ◽  
Ludwig Chenneberg ◽  
Vincent Corcé ◽  
Jean-Philippe Goddard ◽  
Cyril Ollivier ◽  
...  
Keyword(s):  
Cross Coupling ◽  
Coupling Reactions ◽  
Nickel Catalysis ◽  
Cross Coupling Reactions ◽  
Dual Catalysis

Primary alkyl bis-catecholato silicates have been successfully engaged with aryl and heteroaryl bromide substrates in photoredox/nickel dual catalysis to provide cross coupling products.

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