A new copper species based on an azo-compound utilized as a homogeneous catalyst for water oxidation

2015 ◽  
Vol 44 (1) ◽  
pp. 351-358 ◽  
Author(s):  
Wei-Bin Yu ◽  
Qing-Ya He ◽  
Xiu-Fang Ma ◽  
Hua-Tian Shi ◽  
Xianwen Wei
Keyword(s):  
Copper Complex ◽  
Water Oxidation ◽  
Phosphate Buffer ◽  
High Stability ◽  
Room Temperature ◽  
Homogeneous Catalyst ◽  
Copper Species ◽  
Azo Compound ◽  
Mild Conditions

An azo-conjugated Copper complex efficiently catalyzes water oxidation in a phosphate buffer at pH 11 at room temperature and exhibits high stability and activity toward water oxidation under mild conditions with a TOF of 4.0 kPa h−1.

scholarly journals Controlled O2 reduction at a mixed-valent (II,I) Cu2S core

2020 ◽  
Vol 56 (67) ◽  
pp. 9636-9639 ◽  
Author(s):  
Jordan Mangue ◽  
Clément Gondre ◽  
Jacques Pécaut ◽  
Carole Duboc ◽  
Stéphane Ménage ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Copper Complex ◽  
High Stability ◽  
Room Temperature ◽  
Reduction Reactions ◽  
Oxygen Reduction Reactions ◽  
O2 Reduction

Oxygen reduction reactions catalyzed by a mixed-valent copper complex reveal a tuneable H2O2/H2O selectivity at room temperature together with high stability over several cycles.

scholarly journals Stable CAAC-based Ruthenium Complexes for Dynamic Olefin Metathesis Under Mild Conditions

2021 ◽  
Author(s):  
Oleksandr Kravchenko ◽  
Brian J.J. Timmer ◽  
Maurice Biedermann ◽  
Andrew Kentaro Inge ◽  
Olof Ramstrom
Keyword(s):  
Olefin Metathesis ◽  
High Stability ◽  
Room Temperature ◽  
Functional Group ◽  
Biologically Active ◽  
Dynamic Covalent Chemistry ◽  
Mild Conditions ◽  
Cross Metathesis ◽  
Potential Applications ◽  
Metathesis Catalysts

<p>A series of olefin metathesis catalysts bearing cyclic (alkyl)(amino)carbene (CAAC) ligands of varying size and steric demand has been synthesized and evaluated in ring-closing-, self-, and cross-metathesis reactions at room temperature. The catalysts were also probed for potential applications in dynamic covalent chemistry. The majority of the catalysts showed high stability, and remained active in the reaction mixtures for several days, including in methanol-based solutions. Higher temperatures could be used to control the reactivity towards sterically challenging substrates, enabling formation of tetrasubstituted olefins. The CAAC complexes exhibited remarkable functional group tolerance towards heteroaromatic and nucleophilic additives, making them potentially useful in the screening of biologically active compounds.</p>

Enzyme-assisted Cyclization of Chalcones to Flavanones

2020 ◽  
Vol 17 (12) ◽  
pp. 926-931
Author(s):  
Mariana Macías Alonso ◽  
Carlos José Boluda ◽  
Gabriela Díaz Barajas ◽  
Nallely Caldera Sánchez ◽  
Iván Córdova-Guerrero ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Phosphate Buffer ◽  
Room Temperature ◽  
Coupling Constants ◽  
Chemical Methods ◽  
Relative Configuration ◽  
Simple Process ◽  
Mild Conditions ◽  
Reaction Proceeds ◽  
Moderate Yield

Enzyme catalyzed synthesis is an eco-friendly technique in organic synthesis, having several benefits over conventional methods. In the present work, we describe a simple process of laccase and chloroperoxidase assisted cyclization of chalcones, leading to the formation of flavanones. The reaction proceeds in a mixture of phosphate buffer and ethanol, under oxygen atmosphere at room temperature, yielding the corresponding flavanone in good to moderate yield. The relative configuration of the products at C2 is tentatively assigned as S*-flavanone based on the coupling constants with the methylenic protons H3α,β. In comparison to the chemical methods, we describe a process which can be achieved efficiently under mild conditions using oxygen as oxidant.

scholarly journals Stable CAAC-based Ruthenium Complexes for Dynamic Olefin Metathesis Under Mild Conditions

2021 ◽  
Author(s):  
Oleksandr Kravchenko ◽  
Brian J.J. Timmer ◽  
Maurice Biedermann ◽  
Andrew Kentaro Inge ◽  
Olof Ramstrom
Keyword(s):  
Olefin Metathesis ◽  
High Stability ◽  
Room Temperature ◽  
Functional Group ◽  
Biologically Active ◽  
Dynamic Covalent Chemistry ◽  
Mild Conditions ◽  
Cross Metathesis ◽  
Potential Applications ◽  
Metathesis Catalysts

<p>A series of olefin metathesis catalysts bearing cyclic (alkyl)(amino)carbene (CAAC) ligands of varying size and steric demand has been synthesized and evaluated in ring-closing-, self-, and cross-metathesis reactions at room temperature. The catalysts were also probed for potential applications in dynamic covalent chemistry. The majority of the catalysts showed high stability, and remained active in the reaction mixtures for several days, including in methanol-based solutions. Higher temperatures could be used to control the reactivity towards sterically challenging substrates, enabling formation of tetrasubstituted olefins. The CAAC complexes exhibited remarkable functional group tolerance towards heteroaromatic and nucleophilic additives, making them potentially useful in the screening of biologically active compounds.</p>

Fine structural morphology of immunocytes of some molluscs and insects

1990 ◽  
Vol 48 (3) ◽  
pp. 386-387
Author(s):  
S.G. Pal ◽  
G. Baur ◽  
B. Ghosh ◽  
S. Palit ◽  
S. Modak ◽  
...  
Keyword(s):  
Blood Cells ◽  
Phosphate Buffer ◽  
Room Temperature ◽  
Structural Information ◽  
Uranyl Acetate ◽  
Meretrix Meretrix ◽  
Lead Citrate ◽  
Bivalve Molluscs ◽  
Structural Morphology ◽  
Ultrathin Sections

In recent years some of the blood cells of several molluscs and insects are characterised as immunocytes. Similar cells from a few invertebrates from India have been looked into under conventional TEM to register the ultrastructural features. This type of study is first of its kind in the subcontinent. Immunocytes from bivalve molluscs Meretrix meretrix, Laroellidens marqinalis and two insect species, apterygote Ctenolepism a longicaudata and pterygote Gesonula punctifrons provide a new set of fine structural information which forms a basis of comparison with those studied earlier.Immunocytes have been collected from the fresh live species of bivalve molluscs and insects obtained locally at Calcutta. These were fixed in icecold 2% glutaraldehyde in 0.1M phosphate buffer (pH 7.2-7.4) for 1-2 hours at 4-5°C. Subseguently pellets were post-osmicated in 1% OsO4 at room temperature for 1-2 hours. Following dehydration these were embedded in Araldite mixture in plastic capsules and polymerization was effected for 2 days at 60°C. Ultrathin sections were cut in a ultrotome and sections were double stained with Uranyl acetate and lead citrate. These were viewed in a TEM.

SuFEx Activation with Ca(NTf2)2: A Unified Strategy to Access Sulfamides, Sulfamates and Sulfonamides from S(VI) Fluorides

2020 ◽  
Author(s):  
Subham Mahapatra ◽  
Cristian P. Woroch ◽  
Todd W. Butler ◽  
Sabrina N. Carneiro ◽  
Sabrina C. Kwan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Medicinal Chemistry ◽  
Mild Conditions ◽  
Broad Array

<p><br></p> <p>A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide, and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight the application of this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds. </p>

SuFEx Activation with Ca(NTf2)2: A Unified Strategy to Access Sulfamides, Sulfamates and Sulfonamides from S(VI) Fluorides

2020 ◽  
Author(s):  
Subham Mahapatra ◽  
Cristian P. Woroch ◽  
Todd W. Butler ◽  
Sabrina N. Carneiro ◽  
Sabrina C. Kwan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Medicinal Chemistry ◽  
Mild Conditions ◽  
Broad Array

<p><br></p> <p>A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide, and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight the application of this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds. </p>

scholarly journals Practical Synthesis of 2-Iodosobenzoic Acid (IBA) without Contamination by Hazardous 2-Iodoxybenzoic Acid (IBX) under Mild Conditions

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1897
Author(s):  
Hideyasu China ◽  
Nami Kageyama ◽  
Hotaka Yatabe ◽  
Naoko Takenaga ◽  
Toshifumi Dohi
Keyword(s):  
Aqueous Solution ◽  
Room Temperature ◽  
Practical Method ◽  
Hypervalent Iodine ◽  
Mild Conditions ◽  
Sequential Procedures ◽  
Iodine Compounds ◽  
Practical Synthesis ◽  
Iodosobenzoic Acid ◽  
Lower Temperature

We report a convenient and practical method for the preparation of nonexplosive cyclic hypervalent iodine(III) oxidants as efficient organocatalysts and reagents for various reactions using Oxone® in aqueous solution under mild conditions at room temperature. The thus obtained 2-iodosobenzoic acids (IBAs) could be used as precursors of other cyclic organoiodine(III) derivatives by the solvolytic derivatization of the hydroxy group under mild conditions of 80 °C or lower temperature. These sequential procedures are highly reliable to selectively afford cyclic hypervalent iodine compounds in excellent yields without contamination by hazardous pentavalent iodine(III) compound.

A mononuclear copper complex as bifunctional electrocatalyst for CO2 reduction and water oxidation

2021 ◽  
pp. 115106
Author(s):  
Ning-ning Shi ◽  
Wang-jing Xie ◽  
Dong-mei Zhang ◽  
Yu-Hua Fan ◽  
Lian-Sheng Cui ◽  
...  
Keyword(s):  
Copper Complex ◽  
Water Oxidation ◽  
Co2 Reduction ◽  
Bifunctional Electrocatalyst

Organophotoredox-Catalyzed C–H Alkylation of Imidazoheterocycles with Malonates: Total Synthesis of Zolpidem

Synthesis ◽  
2020 ◽  
Author(s):  
Narendra R. Chaubey ◽  
Anant R. Kapdi ◽  
Biswanath Maity
Keyword(s):  
Total Synthesis ◽  
Room Temperature ◽  
Drug Molecule ◽  
Bond Functionalization ◽  
First Report ◽  
Mild Conditions ◽  
The Past ◽  
Hypnotic Drug ◽  
Free Environment

AbstractOrganophotocatalytic C–H bond functionalization has attracted a lot of attention in the past several years due to the possibility of catalyzing reactions in a metal- and peroxide-free environment. Continuing on these lines, an organophotoredox-catalyzed C–H functionalization of imidazo[1,2-a]pyridines and related heterocycles with bromomalonates under mild conditions is reported, providing excellent yields of the products at room temperature. This is the first report involving malonates as coupling partners leading to the synthesis of a range of functionalized products including total synthesis of zolpidem, a sedative­-hypnotic drug molecule.

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