scholarly journals Ligand-field transition-induced C-S bond formation from nickelacycles

2021 ◽  
Author(s):  
Jeongcheol Shin ◽  
Jiseon Lee ◽  
Jong-Min Suh ◽  
Kiyoung Park
Keyword(s):  
Bond Formation ◽  
Cross Coupling ◽  
Ligand Field ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Field Transition

Photoexcitation is one of the acknowledged methods to activate Ni-based cross-coupling reactions, but factors that govern the photoactivity of organonickel complexes have not yet been established. Here we report the...

Copper-catalyzed cross-coupling reactions for C–P bond formation

RSC Advances ◽  
2015 ◽  
Vol 5 (65) ◽  
pp. 52824-52831 ◽  
Author(s):  
Hui Zhang ◽  
Xue-Yan Zhang ◽  
Dao-Qing Dong ◽  
Zu-Li Wang
Keyword(s):  
Bond Formation ◽  
Cross Coupling ◽  
Phosphorus Compounds ◽  
Coupling Reactions ◽  
Cross Coupling Reactions

Phosphorus compounds are important compounds in many areas.

scholarly journals Computational Insights into Intramolecular Cross-Coupling of Quaternary Borate Salts

2021 ◽  
Author(s):  
Florian Matz ◽  
Arif Music ◽  
Dorian Didier ◽  
Thomas C. Jagau
Keyword(s):  
Organic Synthesis ◽  
Energy Barrier ◽  
Density Functional ◽  
Bond Formation ◽  
Cross Coupling ◽  
Coupled Cluster ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Product Distributions ◽  
Borate Salts

Cross-coupling reactions for C-C bond formation represent a cornerstone of organic synthesis. In most cases, they make use of transition metals, which has several downsides. Recently, metal-free alternatives relying on electrochemistry have gained interest. One example of such a reaction is the oxidation of tetraorganoborate salts that initiates aryl-aryl and aryl-alkenyl couplings with promising selectivities. This work investigates the mechanism of this reaction computationally using density functional and coupled-cluster theory. Our calculations reveal a distinct difference between aryl-alkenyl and aryl-aryl couplings: While C-C bond formation occurs irreversibly and without an energy barrier if an alkenyl residue is involved, many intermediates can be identified in aryl-aryl couplings. In the latter case, intramolecular transitions between reaction paths leading to different products are possible. Based on the energy differences between these intermediates, we develop a kinetic model to estimate product distributions for aryl-aryl couplings.<br>

scholarly journals Computational Insights into Intramolecular Cross-Coupling of Quaternary Borate Salts

2021 ◽  
Author(s):  
Florian Matz ◽  
Arif Music ◽  
Dorian Didier ◽  
Thomas C. Jagau
Keyword(s):  
Organic Synthesis ◽  
Energy Barrier ◽  
Density Functional ◽  
Bond Formation ◽  
Cross Coupling ◽  
Coupled Cluster ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Product Distributions ◽  
Borate Salts

Cross-coupling reactions for C-C bond formation represent a cornerstone of organic synthesis. In most cases, they make use of transition metals, which has several downsides. Recently, metal-free alternatives relying on electrochemistry have gained interest. One example of such a reaction is the oxidation of tetraorganoborate salts that initiates aryl-aryl and aryl-alkenyl couplings with promising selectivities. This work investigates the mechanism of this reaction computationally using density functional and coupled-cluster theory. Our calculations reveal a distinct difference between aryl-alkenyl and aryl-aryl couplings: While C-C bond formation occurs irreversibly and without an energy barrier if an alkenyl residue is involved, many intermediates can be identified in aryl-aryl couplings. In the latter case, intramolecular transitions between reaction paths leading to different products are possible. Based on the energy differences between these intermediates, we develop a kinetic model to estimate product distributions for aryl-aryl couplings.<br>

scholarly journals Biocatalytic oxidative cross-coupling reactions for biaryl bond formation

2021 ◽  
Author(s):  
Lara Zetzsche ◽  
Jessica Yazarians ◽  
Suman Chakrabarty ◽  
Meagan Hinze ◽  
April Lukowski ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Bond Formation ◽  
Cross Coupling ◽  
Building Blocks ◽  
Coupling Reactions ◽  
Cytochrome P450 Enzymes ◽  
Cross Coupling Reactions ◽  
Site Selectivity ◽  
Valuable Compounds ◽  
Selective Process

Despite their varied purposes, many indispensable molecules in medicine, materials, and asymmetric catalysis share a biaryl core. The necessity of joining arene building blocks to access these valuable compounds has inspired multiple approaches for biaryl bond formation and challenged chemists to develop increasingly concise and robust methods for this task. Oxidative coupling of two C–H bonds offers an efficient strategy for the formation of a biaryl C–C bond, however, fundamental challenges remain in controlling the reactivity and selectivity for uniting a given pair of substrates. Biocatalytic oxidative cross-coupling reactions have the potential to overcome limitations inherent to small molecule- mediated methods by providing a paradigm with catalyst-controlled selectivity. In this article, we disclose a strategy for biocatalytic cross-coupling through oxidative C–C bond formation using cytochrome P450 enzymes. We demonstrate the ability to catalyze cross-coupling reactions on a panel of phenolic substrates using natural P450 catalysts. Moreover, we engineer a P450 to possess the desired reactivity, site- selectivity, and atroposelectivity by transforming a low-yielding, unselective reaction into a highly efficient and selective process. This streamlined method for constructing sterically hindered biaryl bonds provides a programmable platform for assembling molecules with catalyst-controlled reactivity and selectivity.

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

7,10-Dibromo-2,3-dicyanopyrazinophenanthrene Aggregates as a Photosensitizer for Nickel-Catalyzed Aryl Esterification

Synlett ◽  
2021 ◽  
Author(s):  
Xiaoqiang Yu ◽  
Min He ◽  
Shilei Yang ◽  
Ming Bao
Keyword(s):  
Visible Light ◽  
Carboxylic Acids ◽  
Bond Formation ◽  
Cross Coupling ◽  
Aryl Halides ◽  
Ni Catalyst ◽  
Coupling Reactions ◽  
Formation Reaction ◽  
Cross Coupling Reactions ◽  
Reaction Proceeds

AbstractSelf-assembled aggregates of 7,10-dibromo-2,3-dicyanopyrazinophenanthrene which act as a new organophotocatalyst in combination with Ni catalyst for the Caryl–Oacyl cross-coupling reactions of carboxylic acids with aryl halides are described. This visible-light-induced Caryl–Oacyl bond-formation reaction proceeds smoothly to afford aryl esters with satisfactory to excellent yields.

scholarly journals Palladium-catalyzed C–N and C–O bond formation of N-substituted 4-bromo-7-azaindoles with amides, amines, amino acid esters and phenols

2012 ◽  
Vol 8 ◽  
pp. 2004-2018 ◽  
Author(s):  
Rajendra Surasani ◽  
Dipak Kalita ◽  
A V Dhanunjaya Rao ◽  
K B Chandrasekhar
Keyword(s):  
Amino Acid ◽  
Bond Formation ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Amino Acid Esters ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed ◽  
Acid Esters

Simple and efficient procedures for palladium-catalyzed cross-coupling reactions of N-substituted 4-bromo-7-azaindole (1H-pyrrole[2,3-b]pyridine), with amides, amines, amino acid esters and phenols through C–N and C–O bond formation have been developed. The C–N cross-coupling reaction of amides, amines and amino acid esters takes place rapidly by using the combination of Xantphos, Cs2CO3, dioxane and palladium catalyst precursors Pd(OAc)2/Pd2(dba)3. The combination of Pd(OAc)2, Xantphos, K2CO3 and dioxane was found to be crucial for the C–O cross-coupling reaction. This is the first report on coupling of amides, amino acid esters and phenols with N-protected 4-bromo-7-azaindole derivatives.

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