scholarly journals Electrochemical Benzylic C-H Functionalization with Isocyanides

2021 ◽  
Author(s):  
Shanyu Tang ◽  
Régis Guillot ◽  
Laurence Grimaud ◽  
Maxime Vitale ◽  
Guillaume VINCENT
Keyword(s):  
Anodic Oxidation ◽  
Electrochemical Process ◽  
Biologically Relevant ◽  
Mild Conditions ◽  
Subsequent Addition

We report the challenging direct carbamoylation or cyanation of benzylic C(sp3)-H bonds with an isocyanide via an electrochemical process giving rise to structures which are encountered in several biologically relevant compounds and drugs. This transformation proceeds in mild conditions without the need of external oxidant and avoids the necessity to start from a prefunctionalized benzylic substrate or the deployment of the cation pool method. Anodic oxidation of the benzylic position and subsequent addition of the isocyanide leads to the formation of a C-C bond and to a nitrilium cation which hydrolysis leads to alpha-aryl acetamide derivatives, while elimination of a t-butyl cation delivers alpha-aryl acetonitrile derivatives.

scholarly journals One-Pot Synthesis of α-Substituted Acrylates

SynOpen ◽  
2018 ◽  
Vol 02 (02) ◽  
pp. 0161-0167
Author(s):  
Magdalini Matziari ◽  
Yixin Xie
Keyword(s):  
Amino Acids ◽  
Reaction Times ◽  
Synthetic Method ◽  
One Pot ◽  
Biologically Relevant ◽  
Mild Conditions ◽  
One Pot Synthesis ◽  
Acrylic Esters ◽  
Natural Amino Acids ◽  
Work Up

A simple and efficient synthetic method towards α-substituted acrylic esters has been developed using the Horner–Wadsworth–Emmons (HWE) reaction with HCHO after alkylation of phosphonoacetates in a one-pot reaction. This method allows the smooth introduction of various side-chains, such as natural amino acids and other biologically relevant substituents. The use of mild conditions, inexpensive reagents, short reaction times and simple work-up and purification steps provides an effective and general alternative to cumbersome multistep and low-yielding procedures described to date.

An integrated electrochemical process to convert lignin to value-added products under mild conditions

2016 ◽  
Vol 18 (18) ◽  
pp. 4999-5007 ◽  
Author(s):  
Serafin Stiefel ◽  
Annika Schmitz ◽  
Jens Peters ◽  
Davide Di Marino ◽  
Matthias Wessling
Keyword(s):  
Value Added ◽  
Electrochemical Process ◽  
Mild Conditions ◽  
Value Added Products

The controlled depolymerization of lignin is a promising approach for the generation of value-added compounds from biomass.

scholarly journals CO2-Mediated Pd-Catalyzed Stereo- and Regioselective Arylation of Free Allylamines

2020 ◽  
Author(s):  
Vinod Landge ◽  
Justin Maxwell ◽  
Pratibha Chand-Thakuri ◽  
Mohit Kapoor ◽  
Evan Diemler ◽  
...  
Keyword(s):  
Catalyst Design ◽  
Powerful Method ◽  
Mechanistic Studies ◽  
Atom Economy ◽  
Biologically Relevant ◽  
Mild Conditions ◽  
Selective Functionalization ◽  
Michael Acceptors ◽  
Key Features ◽  
Terminal Olefins

Mizoroki-Heck couplings are a powerful method for elaborating alkene feedstocks. While selective functionalization of terminal olefins has been achieved by catalyst design, selective functionalization of internal olefins has generally required use of directing groups except in the case of Michael acceptors. Allylamine substrates have typically required protection to be suitable for these reactions, decreasing the step and atom economy of these procedures. Herein we demonstrate that the addition of CO<sub>2</sub> (dry ice) allows for the reproducible stereospecific arylation of both secondary and primary allylamines in the presence of a Pd<sup>II</sup> catalyst. Notably, the product 3,3’-diarylallylamine motif is prevalent in a variety of biologically-relevant structures, and this method represents the most straightforward synthesis of these targets to date. Key features of the method are the ability to access relatively mild conditions that facilitate a broad substrate scope, as well as direct diarylation of terminal allylamine substrates. In addition, several complex and therapeutically-relevant molecules are included to demonstrate the utility of the transformation. Mechanistic studies point to an amine-directed reaction where CO<sub>2</sub> serves to protect the substrate and product from degradation.

scholarly journals A modified approach for the synthesis of biologically relevant 5-substituted-2-N-aryl-1,3-oxazole derivatives in mild conditions

2020 ◽  
Vol 14 (1) ◽  
pp. 807-811
Author(s):  
R. Udhayasurian ◽  
K. Sivakumar ◽  
Ayyiliath M. Sajith ◽  
Muthipeedika Nibin Joy
Keyword(s):  
Biologically Relevant ◽  
Mild Conditions ◽  
Oxazole Derivatives

Efficiently degradation of perfluorooctanoic acid in synergic electrochemical process combining cathodic electro-Fenton and anodic oxidation

2019 ◽  
Vol 378 ◽  
pp. 122071 ◽  
Author(s):  
Qingning Wang ◽  
Mingyue Liu ◽  
Hongying Zhao ◽  
Ying Chen ◽  
Fan Xiao ◽  
...  
Keyword(s):  
Anodic Oxidation ◽  
Perfluorooctanoic Acid ◽  
Electrochemical Process

Formation and Characterization of Dispersed Mixed Iron-titanium Oxide Systems by Electrochemical Method

2020 ◽  
Vol 10 (1) ◽  
pp. 25-36
Author(s):  
Alexander F. Dresvyannikov ◽  
Irina O. Grigoryeva ◽  
Leniza R. Salemgaraeva
Keyword(s):  
Anodic Oxidation ◽  
Electrochemical Method ◽  
Structural Characteristics ◽  
Electrical Contact ◽  
Aqueous Media ◽  
Electrochemical Process ◽  
Oxide System ◽  
Oxidation Products ◽  
Anode Current Density ◽  
Oxide Systems

Aims: Anodic polarization behavior of a combined iron-titanium electrode (two metals in electrical contact with each other) in aqueous solutions containing halide ions (F- and Cl-) was studied. Methods: he joint anodic dissolution of titanium and iron with subsequent thermal treatment makes it possible to obtain precursors of a highly dispersed mixed oxide system Fe2O3-TiO2. The phase and elemental composition and structural characteristics of obtained products were examined using X-ray diffraction and scanning electron microscopy. It has been experimentally confirmed that via changing the anode current density, hydrofluoric acid concentration in electrolyte and ratio of the working surface area of contacting metals, it is possible to effectively control the rate of anodic reactions and phase composition and morphology of anodic oxidation products for iron and titanium components in a combined electrode. Results: The main results of this study are as follows: Electrochemical method for the synthesis of complex dispersed oxide system Fe2O3-TiO2 based on joint anodic oxidation of contacting metals in aqueous media was suggested. Relationships between parameters of the electrochemical process and characteristics of the synthesized oxide system were revealed. Conclusion: By varying the parameters of the electrolysis process, it is possible to prepare complex oxyhydroxides with different ratios of iron and titanium, which makes it possible to synthesize precursors of iron titanates of preset composition and structure.

Comparison of a novel electro-Fenton method with Fenton's reagent in treating a highly contaminated wastewater

2001 ◽  
Vol 43 (2) ◽  
pp. 17-24 ◽  
Author(s):  
Y.-H. Huang ◽  
C.-C. Chen ◽  
G.-H. Huang ◽  
S. S. Chou
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Anodic Oxidation ◽  
Batch Reactor ◽  
Heavy Metal Concentration ◽  
Chemical Oxidation ◽  
Electrochemical Process ◽  
Cod Removal ◽  
Fenton Process ◽  
Degradation Reactions

This study applied a novel electrochemical process called the Fered-Fenton method to treat a highly concentrated wastewater. By combining electrochemical reduction and chemical oxidation, the process can remove organic compounds and heavy metals in a batch reactor. A PVC-stabilizer processing wastewater was treated in this investigation owing to its high heavy metal concentration (Pb = 7,500 mg/l) and high organic concentration (COD = 11,000 mg/l). The major organic component was acetate. Direct anodic oxidation showed no effect on COD removal. Fenton's method only removed 36% of COD using 4,000 mg-Fe2+/l and 28,000 mg-H2O2/l dosage. In the Fered-Fenton process, about 89% of COD was removed with 2,000 mg-Fe3+/l and 28,000 mg-H2O2/l. Furthermore, the COD removal attained an efficiency of about 98% for 56,000 mg-H2O2/l used. Results presented herein demonstrate that the Fered-Fenton method is superior to direct anodic oxidation and Fenton's method in this case. Furthermore, the changes of the intermediate compounds including acetate, oxadate, and formate during the reaction were analyzed, which provided us with the information to propose degradation reactions of the wastewater in this system.

An Efficient and Ecofriendly Three-Component Reaction for the Rapid Synthesis of 2-Amino-4H-chromenes Catalyzed by a DABCO­-Based Ionic Liquid

Synthesis ◽  
2018 ◽  
Vol 50 (18) ◽  
pp. 3708-3714 ◽  
Author(s):  
Da-Zhen Xu ◽  
Cheng-Bin Li ◽  
Yu-Wei Li
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Michael Reaction ◽  
Reaction Times ◽  
Rapid Synthesis ◽  
Biologically Relevant ◽  
Mild Conditions ◽  
Three Component Reaction ◽  
Green Strategy

An efficient, economical, and green strategy for the construction of biologically relevant 2-amino-4H-chromene scaffolds via a tandem Knoevenagel–Pinner cyclization–Michael reaction has been successfully developed. In the presence of DABCO-based ionic liquids, two different 2-amino-4H-chromene derivatives, 2-amino-4-(indol-3-yl)-4H-chromenes and 2-amino-4-(pyrazol-4-yl)-4H-chromenes, were prepared in good to excellent yields (81–97%) within short reaction times under mild conditions. All the products are purified by simple crystallization. The catalyst could be recycled for at least five times.

scholarly journals CO2 As A Transient Directing Group for the Oxidative Heck Coupling of Free Allylamines With Aryl Iodides

2020 ◽  
Author(s):  
Vinod Landge ◽  
Justin Maxwell ◽  
Pratibha Chand-Thakuri ◽  
Mohit Kapoor ◽  
Evan Diemler ◽  
...  
Keyword(s):  
Catalyst Design ◽  
Heck Coupling ◽  
Powerful Method ◽  
Atom Economy ◽  
Biologically Relevant ◽  
Mild Conditions ◽  
Selective Functionalization ◽  
Michael Acceptors ◽  
Directing Group ◽  
Terminal Olefins

Oxidative Heck couplings are a powerful method for elaborating alkene feedstocks. While selective functionalization of terminal olefins has been achieved by catalyst design, selective functionalization of internal olefins has generally required use of directing groups except in the case of Michael acceptors. Allylamine substrates have typically required protection to be suitable for these reactions, decreasing the step and atom economy of these procedures. Herein we demonstrate that the addition of CO<sub>2</sub> (dry ice) as a transient directing group allows for the stereospecific arylation of both secondary and primary allylamines in the presence of a Pd<sup>II</sup> catalyst. Notably, the product 3,3’-diarylallylamine motif is prevalent in a variety of biologically-relevant structures, and this method represents the most straightforward synthesis of these targets to date. Key features of the method are the ability to access relatively mild conditions that facilitate a broad substrate scope, as well as direct diarylation of terminal allylamine substrates. In addition, several complex and therapeutically-relevant molecules are included to demonstrate the utility of the transformation.

scholarly journals CO2-Mediated Pd-Catalyzed Stereo- and Regioselective Arylation of Free Allylamines

2020 ◽  
Author(s):  
Vinod Landge ◽  
Justin Maxwell ◽  
Pratibha Chand-Thakuri ◽  
Mohit Kapoor ◽  
Evan Diemler ◽  
...  
Keyword(s):  
Catalyst Design ◽  
Powerful Method ◽  
Mechanistic Studies ◽  
Atom Economy ◽  
Biologically Relevant ◽  
Mild Conditions ◽  
Selective Functionalization ◽  
Michael Acceptors ◽  
Key Features ◽  
Terminal Olefins

Mizoroki-Heck couplings are a powerful method for elaborating alkene feedstocks. While selective functionalization of terminal olefins has been achieved by catalyst design, selective functionalization of internal olefins has generally required use of directing groups except in the case of Michael acceptors. Allylamine substrates have typically required protection to be suitable for these reactions, decreasing the step and atom economy of these procedures. Herein we demonstrate that the addition of CO2 (dry ice) allows for the reproducible stereospecific arylation of both secondary and primary allylamines in the presence of a PdII catalyst. Notably, the product 3,3’-diarylallylamine motif is prevalent in a variety of biologically-relevant structures, and this method represents the most straightforward synthesis of these targets to date. Key features of the method are the ability to access relatively mild conditions that facilitate a broad substrate scope, as well as direct diarylation of terminal allylamine substrates. In addition, several complex and therapeutically-relevant molecules are included to demonstrate the utility of the transformation. Mechanistic studies point to an amine-directed reaction where CO2 serves to protect the substrate and product from degradation.

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