Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Mild, Redox-Neutral Formylation of Aryl Chlorides through the Photocatalytic Generation of Chlorine Radicals.

ABSTRACT: We report a redox-neutral formylation of aryl chlorides that proceeds through selective 2-functionalization of 1,3-dioxolane through nickel and photoredox catalysis. This scalable benchtop approach provides a distinct advantage over traditional reductive carbonylation in that no carbon monoxide, pressurized gas, or stoichiometric reductant is employed. The mild conditions give unprecedented scope from abundant and complex aryl chloride starting materials.

SUBMITTER: Nielsen MK

PROVIDER: S-EPMC5662441 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Mild, Redox-Neutral Formylation of Aryl Chlorides through the Photocatalytic Generation of Chlorine Radicals.

Nielsen Matthew K MK Shields Benjamin J BJ Liu Junyi J Williams Michael J MJ Zacuto Michael J MJ Doyle Abigail G AG

Angewandte Chemie (International ed. in English) 20170523 25

We report a redox-neutral formylation of aryl chlorides that proceeds through selective 2-functionalization of 1,3-dioxolane through nickel and photoredox catalysis. This scalable benchtop approach provides a distinct advantage over traditional reductive carbonylation in that no carbon monoxide, pressurized gas, or stoichiometric reductant is employed. The mild conditions give unprecedented scope from abundant and complex aryl chloride starting materials. ...[more]

PMID: 28471521

Similar Datasets

Redox-Neutral Photocatalytic Cyclopropanation via Radical/Polar Crossover.

Project description:A benchtop stable, bifunctional reagent for the redox-neutral cyclopropanation of olefins has been developed. Triethylammonium bis(catecholato)iodomethylsilicate can be readily prepared on multigram scale. Using this reagent in combination with an organic photocatalyst and visible light, cyclopropanation of an array of olefins, including trifluoromethyl- and pinacolatoboryl-substituted alkenes, can be accomplished in a matter of hours. The reaction is highly tolerant of traditionally reactive functional groups (carboxylic acids, basic heterocycles, alkyl halides, etc.) and permits the chemoselective cyclopropanation of polyolefinated compounds. Mechanistic interrogation revealed that the reaction proceeds via a rapid anionic 3- exo- tet ring closure, a pathway consistent with experimental and computational data.

| S-EPMC6540794 | biostudies-literature

Mild, visible light-mediated decarboxylation of aryl carboxylic acids to access aryl radicals.

Project description:Herein we present the first example of aryl radical formation via the visible light-mediated decarboxylation of aryl carboxylic acids using photoredox catalysis. This method constitutes a mild protocol for the decarboxylation of cheap and abundant aryl carboxylic acids and tolerates both electron-rich substrates and those lacking ortho-substitution. The in situ formation of an acyl hypobromite is proposed to prevent unproductive hydrogen atom abstraction and trapping of the intermediate aroyloxy radical, enabling mild decarboxylation.

| S-EPMC5437376 | biostudies-literature

Redox-Active Reagents for Photocatalytic Generation of the OCF3 Radical and (Hetero)Aryl C-H Trifluoromethoxylation.

Project description:The trifluoromethoxy (OCF3 ) radical is of great importance in organic chemistry. Yet, the catalytic and selective generation of this radical at room temperature and pressure remains a longstanding challenge. Herein, the design and development of a redox-active cationic reagent (1) that enables the formation of the OCF3 radical in a controllable, selective, and catalytic fashion under visible-light photocatalytic conditions is reported. More importantly, the reagent allows catalytic, intermolecular C-H trifluoromethoxylation of a broad array of (hetero)arenes and biorelevant compounds. Experimental and computational studies suggest single electron transfer (SET) from excited photoredox catalysts to 1 resulting in exclusive liberation of the OCF3 radical. Addition of this radical to (hetero)arenes gives trifluoromethoxylated cyclohexadienyl radicals that are oxidized and deprotonated to afford the products of trifluoromethoxylation.

| S-EPMC6278930 | biostudies-literature

Rhodium-Catalyzed Formylation of Unactivated Alkyl Chlorides to Aldehydes.

Project description:The first rhodium-catalyzed formylation of non-activated alkyl chlorides with syn gas (H2 /CO) allows to produce aldehydes in high yields (25 examples). A catalyst optimization study revealed Rh(acac)(CO)2 in the presence of 1,3-bisdiphenylphosphinopropane (DPPP) as the most active catalyst system for this transformation. Key for the success of the reaction is the addition of sodium iodide (NaI) to the reaction system, which leads to the formation of activated alkyl iodides as intermediates. Depending on the reaction conditions, either the linear or branched aldehydes can be preferentially obtained, which is explained by a different mechanism.

| S-EPMC10108320 | biostudies-literature

Visible-Light-Induced Palladium-Catalyzed Generation of Aryl Radicals from Aryl Triflates.

Project description:A mild visible-light-induced Pd-catalyzed intramolecular C-H arylation of amides is reported. The method operates by cleavage of a C(sp2 )-O bond, leading to hybrid aryl Pd-radical intermediates. The following 1,5-hydrogen atom translocation, intramolecular cyclization, and rearomatization steps lead to valuable oxindole and isoindoline-1-one motifs. Notably, this method provides access to products with readily enolizable functional groups that are incompatible with traditional Pd-catalyzed conditions.

| S-EPMC7446712 | biostudies-literature

Redox-Neutral Decarboxylative Cross-Coupling of Oxamates with Aryl Bromides

Project description: Not available

| S-EPMC10996045 | biostudies-literature

Photocatalytic redox-neutral hydroxyalkylation of <i>N</i>-heteroaromatics with aldehydes.

Project description:Hydroxyalkylation of N-heteroaromatics with aldehydes was achieved using a binary hybrid catalyst system comprising an acridinium photoredox catalyst and a thiophosphoric acid organocatalyst. The reaction proceeded through the following sequence: (1) photoredox-catalyzed single-electron oxidation of a thiophosphoric acid catalyst to generate a thiyl radical, (2) cleavage of the formyl C-H bond of the aldehyde substrates by a thiyl radical acting as a hydrogen atom transfer catalyst to generate acyl radicals, (3) Minisci-type addition of the resulting acyl radicals to N-heteroaromatics, and (4) a spin-center shift, photoredox-catalyzed single-electron reduction, and protonation to produce secondary alcohol products. This metal-free hybrid catalysis proceeded under mild conditions for a wide range of substrates, including isoquinolines, quinolines, and pyridines as N-heteroaromatics, as well as both aromatic and aliphatic aldehydes, and tolerated various functional groups. The reaction was applicable to late-stage derivatization of drugs and their leads.

| S-EPMC8163015 | biostudies-literature

Mild, Redox-Neutral Alkylation of Imines Enabled by an Organic Photocatalyst.

Project description:An operationally simple, mild, redox-neutral method for the photoredox alkylation of imines is reported. Utilizing an inexpensive organic photoredox catalyst, alkyl radicals are readily generated from the single-electron oxidation of ammonium alkyl bis(catecholato)silicates and are subsequently engaged in a C-C bond-forming reaction with imines. The process is highly selective, metal-free, and does not require a large excess of the alkylating reagent or the use of acidic additives.

| S-EPMC5369175 | biostudies-literature

Direct C(sp<sup>3</sup>)-H Cross Coupling Enabled by Catalytic Generation of Chlorine Radicals.

Project description:Here we report the development of a C(sp3)-H cross-coupling platform enabled by the catalytic generation of chlorine radicals by nickel and photoredox catalysis. Aryl chlorides serve as both cross-coupling partners and the chlorine radical source for the α-oxy C(sp3)-H arylation of cyclic and acyclic ethers. Mechanistic studies suggest that photolysis of a Ni(III) aryl chloride intermediate, generated by photoredox-mediated single-electron oxidation, leads to elimination of a chlorine radical in what amounts to the sequential capture of two photons. Arylations of a benzylic C(sp3)-H bond of toluene and a completely unactivated C(sp3)-H bond of cyclohexane demonstrate the broad implications of this manifold for accomplishing numerous C(sp3)-H bond functionalizations under exceptionally mild conditions.

| S-EPMC5215658 | biostudies-literature

Generation of Aryl Radicals from Aryl Hydrazines via Catalytic Iodine in Air: Arylation of Substituted 1,4-Naphthoquinones.

Project description:Arylated building blocks or heterocycles are key to myriad applications, including pharmaceutical drug discovery, materials sciences, and many more. Herein, we have reported a mild and efficient strategy for generation of aryl radicals by reacting appropriate aryl hydrazines with catalytic iodine in open air. The aryl radicals were quenched by diversely substituted 1,4-napthoquinones present in the reaction mixture to afford diversely substituted 2,3-napthoquinones in moderate to excellent yield. Control experiments provided insights into the putative reaction mechanism.

| S-EPMC7057683 | 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