Electrochemical synthesis of tetrazoles via metal- and oxidant-free [3 + 2] cycloaddition of azides with hydrazones

2018 ◽  
Vol 20 (23) ◽  
pp. 5271-5275 ◽  
Author(s):  
Zenghui Ye ◽  
Feng Wang ◽  
Yong Li ◽  
Fengzhi Zhang
Keyword(s):  
Functional Groups ◽  
Electrochemical Synthesis ◽  
Cycloaddition Reaction ◽  
Simple Metal ◽  
Reaction Conditions ◽  
Green Protocol

An unprecedented electrochemical [3 + 2] cycloaddition reaction for the synthesis of valuable tetrazoles was developed. Readily available azides and hydrazones were used as the starting materials under simple metal- and oxidant-free reaction conditions. Various functional groups are compatible with this green protocol.

Electrochemical synthesis of Isobenzofuran-1-imines using Oxidative Halocyclization of o‑Alkynylbenzamides

2021 ◽  
Author(s):  
Anandhan Ramasamy ◽  
Mandapati Bhargava Reddy ◽  
Raja Gopal P ◽  
Muthuraaman B
Keyword(s):  
Electrochemical Synthesis ◽  
Reaction Conditions

Electrochemical oxidative 5-exo-dig-oxo-halocyclization of o-alkynylbenzamides was achieved using readily available NaX (X = Cl, Br and I) salts under mild reaction conditions. The use of cheap and highly stable sodium...

Chemical reduction of chlorpyrifos driven by flavin mononucleotide functionalized titanium (IV) dioxide

2020 ◽  
Vol 5 (11) ◽  
Author(s):  
Stephanie Santos Díaz ◽  
Hazim Al-Zubaidi ◽  
Amir C. Ross-Obare ◽  
Sherine O. Obare
Keyword(s):  
Functional Groups ◽  
Organic Contaminants ◽  
Chemical Reduction ◽  
Flavin Mononucleotide ◽  
Reaction Conditions ◽  
Organophosphate Compounds ◽  
Biological Molecule ◽  
Highly Active ◽  
New Directions ◽  
Detrimental Impact

AbstractFor many decades, organohalide and organophosphate compounds have shown significant detrimental impact on the environment. Consequently, strategies for their remediation continue to be an area of emerging need. The reduction of the chlorpyrifos pesticide, a molecule that bears both organohalide and organophosphate functional groups, is an important area of investigation due to it toxic nature. In this report, we demonstrate the effectiveness of the biological molecule, flavin mononucleotide (FMN) toward chemically reducing chlorpyrifos. The FMN was found to be highly active when anchored to nanocrystalline TiO2 surfaces. The results show new directions toward the remediation of organic contaminants under mild reaction conditions.

scholarly journals Development of variously functionalized nitrile oxides

2015 ◽  
Vol 11 ◽  
pp. 1241-1245 ◽  
Author(s):  
Haruyasu Asahara ◽  
Keita Arikiyo ◽  
Nagatoshi Nishiwaki
Keyword(s):  
Carboxylic Acid ◽  
Nucleophilic Substitution ◽  
Functional Groups ◽  
Grignard Reagent ◽  
Cycloaddition Reaction ◽  
Chemical Transformations ◽  
Nitrile Oxides ◽  
Weinreb Amide ◽  
Isoxazole Derivatives ◽  
Acid Esters

N-Methylated amides (N,4-dimethylbenzamide and N-methylcyclohexanecarboxamide) were systematically subjected to chemical transformations, namely, N-tosylation followed by nucleophilic substitution. The amide function was converted to the corresponding carboxylic acid, esters, amides, aldehyde, and ketone upon treatment with hydroxide, alkoxide, amine, diisobutylaluminium hydride and Grignard reagent, respectively. In these transformations, N-methyl-N-tosylcarboxamides behave like a Weinreb amide. Similarly, N-methyl-5-phenylisoxazole-3-carboxamide was converted into 3-functionalized isoxazole derivatives. Since the amide was prepared by the cycloaddition reaction of ethynylbenzene and N-methylcarbamoylnitrile oxide, the nitrile oxide served as the equivalent of the nitrile oxides bearing a variety of functional groups such as carboxy, alkoxycarbonyl, carbamoyl, acyl and formyl moieties.

scholarly journals Visible Light-Enabled Paternò-Büchi Reaction via Triplet Energy Transfer for the Synthesis of Oxetanes

2020 ◽  
Author(s):  
Katie Rykaczewski ◽  
Corinna Schindler
Keyword(s):  
Energy Transfer ◽  
Visible Light ◽  
Uv Light ◽  
Cycloaddition Reaction ◽  
High Energy ◽  
Triplet Energy ◽  
Reaction Conditions ◽  
Triplet Energy Transfer

<div> <p>One of the most efficient ways to synthesize oxetanes is the light-enabled [2+2] cycloaddition reaction of carbonyls and alkenes, referred to as the Paternò-Büchi reaction. The reaction conditions for this transformation typically require the use of high energy UV light to excite the carbonyl, limiting the applications, safety, and scalability. We herein report the development of a visible light-mediated Paternò-Büchi reaction protocol that relies on triplet energy transfer from an iridium-based photocatalyst to the carbonyl substrates. This mode of activation is demonstrated for a variety of aryl glyoxylates and negates the need for both, visible light-absorbing carbonyl starting materials or UV light to enable access to a variety of functionalized oxetanes in up to 99% yield.</p> </div> <br>

scholarly journals Palladium-Catalyzed [3+2] Cycloaddition via Two-Fold 1,3-C(sp3)−H Activation

2020 ◽  
Author(s):  
Hojoon Park ◽  
jin-quan yu
Keyword(s):  
Functional Groups ◽  
Sulfonic Acid ◽  
Cycloaddition Reaction ◽  
Wide Range ◽  
Leaving Group ◽  
Palladium Catalyzed ◽  
Directing Group ◽  
Overall Efficiency ◽  
Weak Coordination ◽  
Single Reaction

<div>Cycloaddition reactions provide an expeditious route to construct ring systems in a highly convergent and stereoselective manner. For a typical cycloaddition reaction to occur, however, the installation of multiple reactive functional groups (π-bonds, leaving group, etc.) are required within the substrates, compromising the overall efficiency or scope of the cycloaddition reaction. Here, we report a palladium-catalyzed [3+2] reaction that utilizes C(sp<sup>3</sup>)–H activation to generate the three-carbon unit for formal cycloaddition with maleimides. We implemented a strategy where the initial C(sp<sup>3</sup>)–H activation/olefin insertion would trigger a relayed, second remote C(sp<sup>3</sup>)–H activation to complete a formal [3+2] cycloaddition. The diastereoselectivity profile of this reaction resembles that of a typical pericyclic cycloaddition reaction in that the relationships between multiple stereocenters are exquisitely controlled in a single reaction. The key to success was the use of weakly coordinating amides as the directing group, as undesired Heck or alkylation pathways were preferred with other types of directing groups. The use of the pyridine-3-sulfonic acid ligands is critical to enable C(sp<sup>3</sup>)–H activation directed by this weak coordination. The method is compatible with a wide range of amide substrates, including lactams, which lead to novel spiro-bicyclic products. The [3+2] product is also shown to undergo a reductive desymmetrization process to access chiral cyclopentane bearing multiple stereocenters with excellent enantioselectivity.</div>

scholarly journals Preparation and Characterization of Chemically-Modified Biomaterials and Their Application as Adsorbents of Penicillin G

2018 ◽  
Vol 1 (1) ◽  
pp. 114-124 ◽  
Author(s):  
Jesie Silva ◽  
Lizebel Morante ◽  
Tesfamichael Demeke ◽  
Jacqueline Baah-Twum ◽  
Abel Navarro
Keyword(s):  
Chemical Modification ◽  
Functional Groups ◽  
Negative Impact ◽  
Ph Dependence ◽  
Sem Analysis ◽  
Penicillin G ◽  
Tea Leaves ◽  
Reaction Conditions ◽  
Spent Tea Leaves

The prevalence of antibiotics in water creates microbial resistance and has a negative impact on the ecosystem. Biomaterials such as spent tea leaves are rich in functional groups and are suitable for chemical modification for diverse applications. This research proposes the use of spent tea leaves of chamomile (CM), green tea (GT), and peppermint (PM) as structural scaffolds for the incorporation of carboxyl, sulfonyl, and thiol groups to improve the adsorption of Penicillin G (Pe). Adsorbents characterization reported a higher number of acidic functional groups, mainly in thiolated products. Scanning electron microscopy (SEM) analysis showed changes on the surfaces of the adsorbents due to reaction conditions, with a stronger effect on thiolated and sulfonated adsorbents. Elemental analysis by Energy dispersive X-ray spectrophotometry (EDS) corroborated the chemical modification by the presence of sulfur atoms and the increase in oxygen/carbon ratios. Batch experiments at different pH shows a strong pH-dependence with a high adsorption at pH 8 for all the adsorbents. The adsorption follows the trend CMs > GTs > PMs. Thiolation and sulfonation reported higher adsorptions, which is most likely due to the sulfur bridge formation, reaching adsorption percentages of 25%. These results create a new mindset in the use of spent tea leaves and their chemical modifications for the bioremediation of antibiotics.

scholarly journals [3 + 2]-Cycloaddition reaction of sydnones with alkynes

2018 ◽  
Vol 14 ◽  
pp. 1317-1348 ◽  
Author(s):  
Veronika Hladíková ◽  
Jiří Váňa ◽  
Jiří Hanusek
Keyword(s):  
Reaction Rate ◽  
Cycloaddition Reaction ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Internal Alkynes

This review covers all known examples of [3 + 2]-cycloaddition between sydnones and both terminal as well as internal alkynes/cycloalkynes taken from literature since its discovery by Huisgen in 1962 up to the current date. Except enumeration of synthetic applications it also covers mechanistic studies, catalysis, effects of substituents and reaction conditions influencing reaction rate and regioselectivity.

Pyridine-bridged bifunctional organocatalysts for the synthesis of cyclic carbonates from carbon dioxide

2019 ◽  
Vol 43 (7-8) ◽  
pp. 248-256
Author(s):  
Quan-Yao Liu ◽  
Lei Shi ◽  
Ning Liu
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Bond ◽  
Cycloaddition Reaction ◽  
Carboxyl Groups ◽  
Cyclic Carbonates ◽  
Reaction Conditions ◽  
Halide Anions ◽  
Simple Filtration ◽  
Hydrogen Bond Donors

Hydroxyl- and carboxyl-functionalized imidazolium halides are used as efficient bifunctional organocatalysts for the synthesis of cyclic carbonates from CO2 and epoxides under mild reaction conditions. Control experiments suggest that the cycloaddition reaction is realized by the combination of the nucleophilic halide anions with hydroxyl and carboxyl groups as hydrogen bond donors. Moreover, the bifunctional organocatalysts can be easily recycled five times by simple filtration; however, a loss of activity was observed.

Electrochemical Synthesis of 2-Hydroxy-para-terphenyls by Dehydrogenative Anodic C–C Cross-Coupling Reaction

Synlett ◽  
2019 ◽  
Vol 30 (10) ◽  
pp. 1174-1177 ◽  
Author(s):  
Sebastian Lips ◽  
Robert Franke ◽  
Siegfried R. Waldvogel
Keyword(s):  
Functional Groups ◽  
Electrochemical Synthesis ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Cross Coupling Reaction ◽  
Wide Range ◽  
Broad Variety ◽  
First Time ◽  
Fast Access

The anodic C–C cross-coupling reaction provides fast access to a wide range of bi- and terarylic scaffolds by electrochemically mediated arylation reactions. Herein, a metal- and reagent-free electrosynthetic protocol for the synthesis of nonsymmetrical 2-hydroxy-para-teraryl derivatives is presented for the first time. It is scalable, easy to conduct, and allows the use of a broad variety of different functional groups.

Sign in / Sign up

Export Citation Format

Share Document