Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Gold Redox Catalysis with a Selenium Cation as a Mild Oxidant.

ABSTRACT: Gold-catalyzed alkyne and allene diselenations were developed. Excellent regioselectivity (trans) and good to excellent yields were achieved (up to 98 % with 2 % catalyst loading) with a wide range of substrates. Mechanistic investigation revealed the formation of a vinyl gold(I) intermediate followed by an intermolecular selenium cation migration, suggesting that a gold(I/III) redox process was successfully implemented under mild conditions.

SUBMITTER: Wang J

PROVIDER: S-EPMC7220824 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Gold Redox Catalysis with a Selenium Cation as a Mild Oxidant.

Wang Jin J Wei Chiyu C Li Xuming X Zhao Pengyi P Shan Chuan C Wojtas Lukasz L Chen Hao H Shi Xiaodong X

Chemistry (Weinheim an der Bergstrasse, Germany) 20200414 27

Gold-catalyzed alkyne and allene diselenations were developed. Excellent regioselectivity (trans) and good to excellent yields were achieved (up to 98 % with 2 % catalyst loading) with a wide range of substrates. Mechanistic investigation revealed the formation of a vinyl gold(I) intermediate followed by an intermolecular selenium cation migration, suggesting that a gold(I/III) redox process was successfully implemented under mild conditions. ...[more]

PMID: 32037616

Similar Datasets

Facilitating Gold Redox Catalysis with Electrochemistry: An Efficient Chemical-Oxidant-Free Approach.

Project description:Due to the high oxidation potential between AuI and AuIII , gold redox catalysis requires at least stoichiometric amounts of a strong oxidant. We herein report the first example of an electrochemical approach in promoting gold-catalyzed oxidative coupling of terminal alkynes. Oxidation of AuI to AuIII was successfully achieved through anode oxidation, which enabled facile access to either symmetrical or unsymmetrical conjugated diynes through homo-coupling or cross-coupling. This report extends the reaction scope of this transformation to substrates that are not compatible with strong chemical oxidants and potentiates the versatility of gold redox chemistry through the utilization of electrochemical oxidative conditions.

| S-EPMC7137689 | biostudies-literature

Highly Efficient and Stereoselective Thioallylation of Alkynes: Possible Gold Redox Catalysis with No Need for a Strong Oxidant.

Project description:Stereoselective thioallylation of alkynes under possible gold redox catalysis was accomplished with high efficiency (as low as 0.1?% catalyst loading, up to 99?% yield) and broad substrate scope (various alkynes, inter- and intramolecular fashion). The gold(I) catalyst acts as both a ?-acid for alkyne activation and a redox catalyst for AuI/III coupling, whereas the sulfonium cation generated in situ functions as a mild oxidant. This novel methodology provides an exciting system for gold redox catalysis without the need for a strong oxidant.

| S-EPMC6121218 | biostudies-literature

Electrochemical gold redox catalysis for selective oxidative arylation.

Project description:The combination of ArB(OH)2 transmetallation with cationic gold(I) [LAu]+ and electrochemical anodic oxidation (EAO) approach was successfully developed for the preparation of AuIII-Ar intermediate for the first time. This in-situ generated aryl gold intermediate gave rapid and controllable transmetallation with ArB(OH)2 or alkyne followed by reductive elimination to generate either di-aryl coupling or sp2-sp Sonogashira-type coupling products under mild conditions with no need of external oxidants, which significantly extended the versatility of electrochemical approach in promoting gold redox catalysis.

| S-EPMC10723655 | biostudies-literature

Alkyne Trifunctionalization via Divergent Gold Catalysis: Combining π-Acid Activation, Vinyl-Gold Addition, and Redox Catalysis.

Project description:Here we report the first example of alkyne trifunctionalization through simultaneous construction of C-C, C-O, and C-N bonds via gold catalysis. With the assistance of a γ-keto directing group, sequential gold-catalyzed alkyne hydration, vinyl-gold nucleophilic addition, and gold(III) reductive elimination were achieved in one pot. Diazonium salts were identified as both electrophiles (N source) and oxidants (C source). Vinyl-gold(III) intermediates were revealed as effective nucleophiles toward diazonium, facilitating nucleophilic addition and reductive elimination with high efficiency. The rather comprehensive reaction sequence was achieved with excellent yields (up to 95%) and broad scope (>50 examples) under mild conditions (room temperature or 40 °C).

| S-EPMC10270734 | biostudies-literature

Thiophenium Salts as New Oxidant for Redox Polymerization under Mild- and Low-Toxicity Conditions.

Project description:In mild conditions (under air, room temperature, no monomer purification and without any energy activation), redox free radical polymerization (RFRP) is considered as one of the most effective methods to polymerize (meth)acrylate monomers. In the past several years, there has been a growing interest in research on the development of new redox initiating systems (RISs), thanks mainly to the evolution of toxicity labeling and the stability issue of the current RIS based on peroxide and aromatic amine. In this study, a new, low-toxicity RIS based on thiophenium salt as the oxidant species is presented with various reductive species. The reactivity and the stability of the proposed RISs are investigated and the synthesis of new thiophenium salts reported.

| S-EPMC9861688 | biostudies-literature

Regioselective Crossed Aldol Reactions under Mild Conditions via Synergistic Gold-Iron Catalysis

Project description: Not available

| S-EPMC10798669 | biostudies-literature

Catalytic oxidant scavenging by selenium-containing compounds: Reduction of selenoxides and N-chloramines by thiols and redox enzymes.

Project description:Myeloperoxidase produces strong oxidants during the immune response to destroy invading pathogens. However, these oxidants can also cause tissue damage, which contributes to the development of numerous inflammatory diseases. Selenium containing compounds, including selenomethionine (SeMet) and 1,4-anhydro-5-seleno-D-talitol (SeTal), react rapidly with different MPO-derived oxidants to form the respective selenoxides (SeMetO and SeTalO). This study investigates the susceptibility of these selenoxides to undergo reduction back to the parent compounds by intracellular reducing systems, including glutathione (GSH) and the glutathione reductase and thioredoxin reductase systems. GSH is shown to reduce SeMetO and SeTalO, with consequent formation of GSSG with apparent second order rate constants, k2, in the range 103-104M-1s-1. Glutathione reductase reduces both SeMetO and SeTalO at the expense of NADPH via formation of GSSG, whereas thioredoxin reductase acts only on SeMetO. The presence of SeMet and SeTal also increased the rate at which NADPH was consumed by the glutathione reductase system in the presence of N-chloramines. In contrast, the presence of SeMet and SeTal reduced the rate of NADPH consumption by the thioredoxin reductase system after addition of N-chloramines, consistent with the rapid formation of selenoxides, but only slow reduction by thioredoxin reductase. These results support a potential role of seleno compounds to act as catalytic scavengers of MPO-derived oxidants, particularly in the presence of glutathione reductase and NADPH, assuming that sufficient plasma levels of the parent selenoether can be achieved in vivo following supplementation.

| S-EPMC5408155 | biostudies-literature

Chiral Hemilabile P,N-Ligand-Assisted Gold Redox Catalysis for Enantioselective Alkene Aminoarylation.

Project description:Enantioselective, intermolecular alkene arylamination was achieved through gold redox catalysis. Screening of ligands revealed chiral P,N ligands as the optimal choice, giving alkene aminoarylation with good yields (up to 80 %) and excellent stereoselectivity (up to 99 : 1 er). As the first example of enantioselective gold redox catalysis, this work confirmed the feasibility of applying a chiral ligand at the gold(I) stage, with the stereodetermining step (SDS) at the gold(III) intermediate, thus opening up a new way to conduct gold redox catalysis with stereochemistry control.

| S-EPMC9254727 | biostudies-literature

Gold redox catalysis for cyclization/arylation of allylic oximes: synthesis of isoxazoline derivatives.

Project description:Base-assisted diazonium activation has been employed to promote gold(i)/(iii) redox catalysis toward allylic oxime cyclization/aryl coupling. Functional isoxazolines were prepared with good to excellent yields, while the alternative photoactivation method provided trace amounts of the isoxazoline products. This study further broadens the scope of gold redox chemistry.

| S-EPMC6641983 | biostudies-literature

Gold Redox Catalysis through Base-Initiated Diazonium Decomposition toward Alkene, Alkyne, and Allene Activation.

Project description:The discovery of photoassisted diazonium activation toward gold(I) oxidation greatly extended the scope of gold redox catalysis by avoiding the use of a strong oxidant. Some practical issues that limit the application of this new type of chemistry are the relative low efficiency (long reaction time and low conversion) and the strict reaction condition control that is necessary (degassing and inert reaction environment). Herein, an alternative photofree condition has been developed through Lewis base induced diazonium activation. With this method, an unreactive AuI catalyst was used in combination with Na2 CO3 and diazonium salts to produce a AuIII intermediate. The efficient activation of various substrates, including alkyne, alkene and allene was achieved, followed by rapid AuIII reductive elimination, which yielded the C-C coupling products with good to excellent yields. Relative to the previously reported photoactivation method, our approach offered greater efficiency and versatility through faster reaction rates and broader reaction scope. Challenging substrates such as electron rich/neutral allenes, which could not be activated under the photoinitiation conditions (<5 % yield), could be activated to subsequently yield the desired coupling products in good to excellent yield.

| S-EPMC5671776 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data