scholarly journals Intermolecular dialkylation of alkenes with two distinct C(sp3)─H bonds enabled by synergistic photoredox catalysis and iron catalysis

2019 ◽  
Vol 5 (3) ◽  
pp. eaav9839 ◽  
Author(s):  
Xuan-Hui Ouyang ◽  
Yang Li ◽  
Ren-Jie Song ◽  
Ming Hu ◽  
Shenglian Luo ◽  
...  
Keyword(s):  
Functional Group ◽  
Coupling Reactions ◽  
Photoredox Catalysis ◽  
Dicarbonyl Compounds ◽  
Iron Catalysis ◽  
Reduction Potentials ◽  
Dehydrogenative Coupling ◽  
Promotion System ◽  
Carbon Carbon Bonds ◽  
Single Reaction

The functionalization of unactivated C(sp3)─H bonds represents one of the most powerful and most atom-economical tools for the formation of new carbon-based chemical bonds in synthesis. Although cross-dehydrogenative coupling reactions of two distinct C─H bonds for the formation of carbon-carbon bonds have been well investigated, controlled functionalizations of two or more different C(sp3)─H bonds across a functional group or a molecule (e.g., an alkene or alkyne) in a single reaction remain challenging. Here, we present a three-component dialkylation of alkenes with common alkanes and 1,3-dicarbonyl compounds via synergistic photoredox catalysis and iron catalysis for the synthesis of two functionalized 1,3-dicarbonyl compounds. Mechanistic studies suggest that the photoredox catalysis serves as a promotion system to allow the dialkylation to proceed under mild conditions by reducing the oxidation and reduction potentials of the iron intermediates and the reaction partners.

scholarly journals Copper-Catalyzed Direct Alkylation of Perfluoroarenes with Hydrocarbons

2019 ◽  
Author(s):  
Weilong Xie ◽  
Joon Heo ◽  
Dongwook Kim ◽  
Sukbok Chang
Keyword(s):  
Bond Activation ◽  
Copper Catalyst ◽  
Catalyst System ◽  
Side Reactions ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Dehydrogenative Coupling ◽  
Carbon Carbon Bonds ◽  
Pseudo Halides ◽  
Direct Use

Construction of carbon–carbon bonds is one of the most essential tools in chemical synthesis. In the previously established cross-coupling reactions, pre-functionalized starting materials are employed usually in the form of arylor alkyl (pseudo)halides or their metallated derivatives. However, direct use of arenes and alkanes via a twofold oxidative C–H bond activation strategy to access chemoselective C(sp2 )‒C(sp3 ) cross-couplings is highly challenging due to the low reactivity of carbon–hydrogen (C–H) bonds and the difficulty in suppressing side reactions such as homocouplings. Herein, we present a copper-catalyzed cross-dehydrogenative coupling of perfluoroarenes with alkanes. Mechanistic information was obtained by combining experimental and computational studies to suggest that the optimal diketimine copper catalyst system plays a dual role to activate both sp3 and sp2 C‒H bonds.

scholarly journals Tetrabutylphosphonium 4-ethoxyvalerate as a biomass-originated media for homogeneous palladium-catalyzed Hiyama coupling reactions

2020 ◽  
Vol 74 (12) ◽  
pp. 4593-4598
Author(s):  
László Orha ◽  
Ábrahám Papp ◽  
József M. Tukacs ◽  
László Kollár ◽  
László T. Mika
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Functional Group ◽  
Cross Coupling ◽  
Catalyst System ◽  
Catalyst Precursor ◽  
Coupling Reactions ◽  
Tetrabutylammonium Fluoride ◽  
Carbon Carbon Bonds ◽  
Palladium Catalyzed

Abstract The introduction of a biomass-derived ionic liquid into the Hiyama coupling reactions, which has been considered as a powerful tool for the synthesis of symmetrically and non-symmetrically substituted biaryl structures, could further control or even reduce the environmental impact of this transformation. It was shown that tetrabutylphosphonium 4-ethoxyvalerate, a γ-valerolactone-based ionic liquid, can be utilized as an alternative solvent to create carbon–carbon bonds between aryl iodides and functionalized organosilanes in the presence of 1 mol% Pd under typical Hiyama conditions (130 °C, 24 h, tetrabutylammonium fluoride activator). A comparison of different ionic liquids was performed, and the effects of the catalyst precursor and the moisture content of the reaction mixture on the activity of the catalyst system were investigated. The functional group tolerance was also studied, resulting in 15 cross-coupling products (3a–o) with isolated yields of 45–72% and excellent purity (> 98%).

scholarly journals Copper-Catalyzed Direct Alkylation of Perfluoroarenes with Hydrocarbons

2019 ◽  
Author(s):  
Weilong Xie ◽  
Joon Heo ◽  
Dongwook Kim ◽  
Sukbok Chang
Keyword(s):  
Bond Activation ◽  
Copper Catalyst ◽  
Catalyst System ◽  
Side Reactions ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Dehydrogenative Coupling ◽  
Carbon Carbon Bonds ◽  
Pseudo Halides ◽  
Direct Use

Construction of carbon–carbon bonds is one of the most essential tools in chemical synthesis. In the previously established cross-coupling reactions, pre-functionalized starting materials are employed usually in the form of arylor alkyl (pseudo)halides or their metallated derivatives. However, direct use of arenes and alkanes via a twofold oxidative C–H bond activation strategy to access chemoselective C(sp2 )‒C(sp3 ) cross-couplings is highly challenging due to the low reactivity of carbon–hydrogen (C–H) bonds and the difficulty in suppressing side reactions such as homocouplings. Herein, we present a copper-catalyzed cross-dehydrogenative coupling of perfluoroarenes with alkanes. Mechanistic information was obtained by combining experimental and computational studies to suggest that the optimal diketimine copper catalyst system plays a dual role to activate both sp3 and sp2 C‒H bonds.

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.

Transition-Metal-Free Synthetic Strategies for the Cross-Coupling Reactions in Water: A Green Approach

2020 ◽  
Vol 07 ◽  
Author(s):  
Tanmay Chatterjee ◽  
Nilanjana Mukherjee
Keyword(s):  
Transition Metal ◽  
Organic Solvents ◽  
Aqueous Media ◽  
Cross Coupling ◽  
Transition Metal Catalysts ◽  
Synthetic Methods ◽  
Coupling Reactions ◽  
Organic Transformations ◽  
Green Approach ◽  
Dehydrogenative Coupling

Abstract: A natural driving force is always working behind the synthetic organic chemists towards the development of ‘green’ synthetic methodologies for the synthesis of useful classes of organic molecules having potential applications. The majority of the essential classes of organic transformations, including C-C and C-X (X = heteroatom) bond-forming crosscoupling reactions, cross dehydrogenative-coupling (CDC) mostly rely on the requirement of transition-metal catalysts and hazardous organic solvents. Hence, the scope in developing green synthetic strategies by avoiding the use of transitionmetal catalysts and hazardous organic solvents for those important and useful classes of organic transformations is very high. Hence, several attempts are made so far. Water being the most abundant, cheap, and green solvent in the world; numerous synthetic methods have been developed in an aqueous medium. In this review, the development of transitionmetal- free green synthetic strategies for various important classes of organic transformations such as C-C and C-X bondforming cross-coupling, cross dehydrogenative-coupling, and oxidative-coupling in an aqueous media is discussed.

scholarly journals On the Use of Iron in Organic Chemistry

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1349 ◽  
Author(s):  
Arnar Guðmundsson ◽  
Jan-E. Bäckvall
Keyword(s):  
Organic Chemistry ◽  
Redox Potential ◽  
Potential Range ◽  
Coupling Reactions ◽  
Base Metals ◽  
Metal Catalysis ◽  
Iron Catalysis ◽  
Cross Coupling Reactions ◽  
Life On Earth ◽  
Palladium Platinum

Transition metal catalysis in modern organic synthesis has largely focused on noble transition metals like palladium, platinum and ruthenium. The toxicity and low abundance of these metals, however, has led to a rising focus on the development of the more sustainable base metals like iron, copper and nickel for use in catalysis. Iron is a particularly good candidate for this purpose due to its abundance, wide redox potential range, and the ease with which its properties can be tuned through the exploitation of its multiple oxidation states, electron spin states and redox potential. This is a fact made clear by all life on Earth, where iron is used as a cornerstone in the chemistry of living processes. In this mini review, we report on the general advancements in the field of iron catalysis in organic chemistry covering addition reactions, C-H activation, cross-coupling reactions, cycloadditions, isomerization and redox reactions.

Base-Free Synthesis and Synthetic Application of Novel 3-(organochalcogenyl)prop-2-yn-1-yl Esters: Promising Anticancer Agents

Synthesis ◽  
2021 ◽  
Author(s):  
Fabiane Gritzenco ◽  
Jean Carlo Kazmierczak ◽  
Thiago Anjos ◽  
Adriane Sperança ◽  
Maura Luise Bruckchem Peixoto ◽  
...  
Keyword(s):  
Anticancer Agents ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Chalcogen Bond ◽  
Cross Coupling Reactions ◽  
Air Atmosphere ◽  
Carbon Carbon Bonds ◽  
Palladium Catalyzed ◽  
Synthetic Application

This manuscript portrays the CuI-catalyzed Csp-chalcogen bond formation through cross-coupling reactions of propynyl esters and diorganyl dichalcogenides by using DMSO as solvent, at room temperature, under base-free and open-to-air atmosphere. Generally, the reactions have proceeded very smoothly, being tolerant to range of substituents present in both substrates, affording the novel 3-(organochalcogenyl)prop-2-yn-1-yl esters in moderate to good yields. Noteworthy, the 3-(butylselanyl)prop-2-yn-1-yl benzoate proved to be useful as synthetic precursor in palladium-catalyzed Suzuki and Sonogashira type cross-coupling reactions by replacing the carbon-chalcogen bond by new carbon-carbon bonds. Moreover, the 3-(phenylselanyl)prop-2-yn-1-yl benzoate has shown promising in vitro activity against glioblastoma cancer cells.

Cross dehydrogenative coupling (CDC) of aldehydes with N-hydroxyimides by visible light photoredox catalysis

RSC Advances ◽  
2015 ◽  
Vol 5 (56) ◽  
pp. 44928-44932 ◽  
Author(s):  
Milan Dinda ◽  
Chandan Bose ◽  
Tridev Ghosh ◽  
Soumitra Maity
Keyword(s):  
Visible Light ◽  
Photoredox Catalysis ◽  
Dehydrogenative Coupling

A visible light mediated cross-dehydrogenative-coupling (CDC) reaction has been developed for the synthesis of N-hydroxyester derivatives from aldehydes and N-hydroxyimides.

Tunable Ligand Effects on Ruthenium Catalyst Activity for Selectively Preparing Imines or Amides by Dehydrogenative Coupling Reactions of Alcohols and Amines

2017 ◽  
Vol 23 (52) ◽  
pp. 12795-12804 ◽  
Author(s):  
Takafumi Higuchi ◽  
Risa Tagawa ◽  
Atsuhiro Iimuro ◽  
Shoko Akiyama ◽  
Haruki Nagae ◽  
...  
Keyword(s):  
Catalyst Activity ◽  
Ruthenium Catalyst ◽  
Coupling Reactions ◽  
Ligand Effects ◽  
Dehydrogenative Coupling
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