sp2 C–H bond activation in water and catalytic cross-coupling reactions

2013 ◽  
Vol 42 (13) ◽  
pp. 5744 ◽  
Author(s):  
Bin Li ◽  
Pierre H. Dixneuf
Keyword(s):  
Bond Activation ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions

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.

ChemInform Abstract: Pd-Catalyzed sp2-sp Cross-Coupling Reactions Involving C-F Bond Activation in Highly Fluorinated Nitrobenzene Systems.

ChemInform ◽  
2013 ◽  
Vol 44 (23) ◽  
pp. no-no
Author(s):  
Matthew R. Cargill ◽  
Graham Sandford ◽  
Pinar Kilickiran ◽  
Gabriele Nelles
Keyword(s):  
Bond Activation ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions

Deoxygenative Transition-Metal-Promoted Reductive Coupling and Cross-Coupling of Alcohols and Epoxides

Synthesis ◽  
2020 ◽  
Vol 53 (02) ◽  
pp. 267-278
Author(s):  
Kenneth M. Nicholas ◽  
Chandrasekhar Bandari
Keyword(s):  
Transition Metal ◽  
Bond Activation ◽  
Bond Formation ◽  
Cross Coupling ◽  
Transition Metal Catalysts ◽  
Coupling Reactions ◽  
Reductive Coupling ◽  
Practical Applications ◽  
Cross Coupling Reactions ◽  
Carbon Carbon Bond

AbstractThe prospective utilization of abundant, CO2-neutral, renewable feedstocks is driving the discovery and development of new reactions that refunctionalize oxygen-rich substrates such as alcohols and polyols through C–O bond activation. In this review, we highlight the development of transition-metal-promoted reactions of renewable alcohols and epoxides that result in carbon–carbon bond-formation. These include reductive self-coupling reactions and cross-coupling reactions of alcohols with alkenes and arene derivatives. Early approaches to reductive couplings employed stoichiometric amounts of low-valent transition-metal reagents to form the corresponding hydrocarbon dimers. More recently, the use of redox-active transition-metal catalysts together with a reductant has enhanced the practical applications and scope of the reductive coupling of alcohols. Inclusion of other reaction partners with alcohols such as unsaturated hydrocarbons and main-group organometallics has further expanded the diversity of carbon skeletons accessible and the potential for applications in chemical synthesis. Catalytic reductive coupling and cross-coupling reactions of epoxides are also highlighted. Mechanistic insights into the means of C–O activation and C–C bond formation, where available, are also highlighted.1 Introduction2 Stoichiometric Reductive Coupling of Alcohols3 Catalytic Reductive Coupling of Alcohols3.1 Heterogeneous Catalysis3.2 Homogeneous Catalysis4 Reductive Cross-Coupling of Alcohols4.1 Reductive Alkylation4.2 Reductive Addition to Olefins5 Epoxide Reductive Coupling Reactions6 Conclusions and Future Directions

scholarly journals Well-Defined Pre-Catalysts in Amide and Ester Bond Activation

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 215 ◽  
Author(s):  
Sandeep R. Vemula ◽  
Michael R. Chhoun ◽  
Gregory R. Cook
Keyword(s):  
Transition Metal ◽  
Bond Activation ◽  
Bond Cleavage ◽  
Cross Coupling ◽  
Ester Bond ◽  
Coupling Reactions ◽  
Catalytic Systems ◽  
Design And Synthesis ◽  
Cross Coupling Reactions ◽  
Made In

Over the past few decades, transition metal catalysis has witnessed a rapid and extensive development. The discovery and development of cross-coupling reactions is considered to be one of the most important advancements in the field of organic synthesis. The design and synthesis of well-defined and bench-stable transition metal pre-catalysts provide a significant improvement over the current catalytic systems in cross-coupling reactions, avoiding excess use of expensive ligands and harsh conditions for the synthesis of pharmaceuticals, agrochemicals and materials. Among various well-defined pre-catalysts, the use of Pd(II)-NHC, particularly, provided new avenues to expand the scope of cross-coupling reactions incorporating unreactive electrophiles, such as amides and esters. The strong σ-donation and tunable steric bulk of NHC ligands in Pd-NHC complexes facilitate oxidative addition and reductive elimination steps enabling the cross-coupling of broad range of amides and esters using facile conditions contrary to the arduous conditions employed under traditional catalytic conditions. Owing to the favorable catalytic activity of Pd-NHC catalysts, a tremendous progress was made in their utilization for cross-coupling reactions via selective acyl C–X (X=N, O) bond cleavage. This review highlights the recent advances made in the utilization of well-defined pre-catalysts for C–C and C–N bond forming reactions via selective amide and ester bond cleavage.

Protocol for Palladium/N-Heterocyclic Carbene-Catalyzed Suzuki–Miyaura Cross-Coupling of Amides by N–C(O) Activation

Synthesis ◽  
2020 ◽  
Author(s):  
Peng Lei ◽  
Guangchen Li ◽  
Michal Szostak ◽  
Yun Ling ◽  
Jie An ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Room Temperature ◽  
Bond Activation ◽  
Process Development ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Amide Bonds ◽  
Cross Coupling Reactions ◽  
Synthetic Procedure ◽  
Operational Simplicity

AbstractAmides are among the most important and ubiquitous functional groups in organic chemistry and process development. In this Practical Synthetic Procedure, a protocol for the Suzuki–Miyaura cross-coupling of amides by selective N–C(O) bond activation catalyzed by commercially available, air- and moisture-stable palladium/N-heterocyclic carbene (NHC) complexes is described. The procedure described involves [Pd(IPr)(cin)Cl] [IPr = 2,6-(diisopropylphenyl)imidazol-2-ylidene, cin = cinnamyl] at 0.10 mol% at room temperature and is performed on decagram scale. Furthermore, a procedure for the synthesis of amide starting materials is accomplished via selective N-tert-butoxycarbonylation, which is the preferred method over N-acylation. The present protocol carries advantages of operational simplicity, commercial availability of catalysts, and excellent conversions at low catalyst loadings. The method is generally useful for activation of N–C(O) amide bonds in a broad spectrum of amide precursors. The protocol should facilitate the implementation of amide cross-coupling reactions.

Synthesis of Benzamide Derivatives by the Reaction of Arenes and Isocyanides through a C–H Bond Activation Strategy

Synlett ◽  
2017 ◽  
Vol 29 (01) ◽  
pp. 94-98 ◽  
Author(s):  
Mehdi Khalaj ◽  
Mahboubeh Taherkhani ◽  
Seyed Mousavi-Safavi ◽  
Jafar Akbari
Keyword(s):  
Bond Activation ◽  
Bond Formation ◽  
Cross Coupling ◽  
Aryl Halides ◽  
Coupling Reactions ◽  
Benzene Derivatives ◽  
Formation Reaction ◽  
Cross Coupling Reactions ◽  
Carbon Carbon Bond ◽  
Benzamide Derivatives

A carbon–carbon bond formation reaction between isocyanides and benzene derivatives is reported. In contrast to traditional cross-coupling reactions, which require aryl halides or pseudohalides, we use a palladium catalyst to generate the aryl–palladium through C–H bond activation of arenes. This method offers an attractive approach to a range of benzamides from readily accessible benzene derivatives.

scholarly journals Photo-Induced Thiolate Catalytic Activation of Inert Caryl-Hetero Bonds for Radical Borylation

2020 ◽  
Author(s):  
Shun Wang ◽  
Hua Wang ◽  
Burkhard Koenig
Keyword(s):  
Bond Activation ◽  
Reducing Power ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
Catalytic Activation ◽  
Cross Coupling Reactions ◽  
Recent Developments ◽  
Leaving Groups ◽  
Metal Catalyzed

Cross-coupling reactions are essential tools in modern synthesis of drugs, natural products and materials. The recent developments in photocatalytic radical generation have improved and expanded the classic metal-catalyzed cross coupling reactions even further. However, for sp<sup>2</sup> cross coupling reactions aryl halides or related active leaving groups, such as triflates, are required. Substituted arenes bearing strong C-X bonds remain inert to current methods. We describe now a new thiolate photocatalysis for the activation of inert substituted arenes in ipso-borylation reactions. This catalytic system exhibits strong reducing power and allows the borylation of stable C<sub>aryl</sub>−F, C<sub>aryl</sub>−O, C<sub>aryl</sub>-N and C<sub>aryl</sub>−S bonds, which are considered as chemically stable at mild reaction conditions. Our method considerably widens the available substrate scope of aryl radical precursors and we anticipate that this report will inspire new chemistry based on inert chemical bond activation.

Air-stable phosphine oxides as preligands for catalytic activation reactions of C-Cl, C-F, and C-H bonds

2006 ◽  
Vol 78 (2) ◽  
pp. 209-214 ◽  
Author(s):  
Lutz Ackermann ◽  
Robert Born ◽  
Julia H. Spatz ◽  
Andreas Althammer ◽  
Christian J. Gschrei
Keyword(s):  
Bond Activation ◽  
Bond Formation ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phosphine Oxides ◽  
Aryl Chlorides ◽  
Catalytic Activation ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
Metal Catalyzed

Studies on the use of easily accessible heteroatom-substituted secondary phosphine oxides as preligands for cross-coupling reactions are described. These air-stable sterically hindered phosphine oxides allow for efficient palladium-catalyzed Suzuki- and nickel-catalyzed Kumada-coupling reactions using electronically deactivated aryl chlorides. In addition, they enable nickel-catalyzed coupling reactions of magnesium organyls with aryl fluorides at ambient temperature, and ruthenium-catalyzed coupling reactions of aryl chlorides via C-H bond activation. Finally, the application of modular diamino phosphine chlorides as preligands for a variety of transition-metal-catalyzed C-C and C-N bond formation reactions employing electron-rich aryl chlorides is presented.

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