Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Transition-metal-free alkynylation of aryl chlorides.

ABSTRACT: Two sets of conditions have been developed for a base-mediated, transition-metal-free alkynylation of aryl chlorides that proceeds via benzyne intermediates. The first set of conditions involves the use of TMPLi base in a pentane/THF mixture at 25 °C. The second set involves use of a metal alkoxide base in dioxane at elevated temperature. Reasonable functional group tolerance has been observed. Fluoro, trifluoromethyl, silyl, cyano, and alcohol functionalities are compatible with the reaction conditions.

SUBMITTER: Truong T

PROVIDER: S-EPMC3155656 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Transition-metal-free alkynylation of aryl chlorides.

Truong Thanh T Daugulis Olafs O

Organic letters 20110725 16

Two sets of conditions have been developed for a base-mediated, transition-metal-free alkynylation of aryl chlorides that proceeds via benzyne intermediates. The first set of conditions involves the use of TMPLi base in a pentane/THF mixture at 25 °C. The second set involves use of a metal alkoxide base in dioxane at elevated temperature. Reasonable functional group tolerance has been observed. Fluoro, trifluoromethyl, silyl, cyano, and alcohol functionalities are compatible with the reaction co ...[more]

PMID: 21786825

Similar Datasets

Transition-Metal-Free Coupling of Polyfluorinated Arenes and Functionalized, Masked Aryl Nucleophiles.

Project description:A chemoselective C(sp2 )-C(sp2 ) coupling of sufficiently electron-deficient fluorinated arenes and functionalized N-aryl-N'-silyldiazenes as masked aryl nucleophiles is reported. The fluoride-promoted transformation involves the in situ generation of the aryl nucleophile decorated with various sensitive functional groups followed by a stepwise nucleophilic aromatic substitution (SN Ar). These reactions typically proceed at room temperature within minutes. This catalytic process allows for the functionalization of both coupling partners, furnishing highly fluorinated biaryls in good yields.

| S-EPMC8453572 | biostudies-literature

Solvent- and transition metal-free amide synthesis from phenyl esters and aryl amines.

Project description:A general, economical, and environmentally friendly method of amide synthesis from phenyl esters and aryl amines was developed. This new method has significant advantages compared to previously reported palladium-catalyzed approaches. The reaction is performed transition metal- and solvent-free, using a cheap and environmentally benign base, NaH. This approach enabled us to obtain target amides in high yields with high atom economy.

| S-EPMC9059645 | biostudies-literature

Base-Free Pd-Catalyzed C-Cl Borylation of Fluorinated Aryl Chlorides.

Project description:Catalytic C-X borylation of aryl halides containing two ortho-fluorines has been found to be challenging, as most previous methods require stoichiometric amounts of base and the polyfluorinated aryl boronates suffer from protodeboronation, which is accelerated by ortho-fluorine substituents. Herein, we report that a combination of Pd(dba)2 (dba=dibenzylideneacetone) with SPhos (2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl) as a ligand is efficient to catalyze the C-Cl borylation of aryl chlorides containing two ortho-fluorine substituents. This method, conducted under base-free conditions, is compatible with the resulting di-ortho-fluorinated aryl boronate products which are sensitive to base.

| S-EPMC7986610 | biostudies-literature

Photoinduced transition-metal- and external-photosensitizer-free intramolecular aryl rearrangement via C(Ar)-O bond cleavage.

Project description:The use of photochemical reactions that do not require expensive photocatalysts or transition metals is an environmentally friendly strategy for accomplishing a variety of structural transformations. Herein, we report a protocol for photoinduced transition-metal- and external-photocatalyst-free intramolecular heteroaryl/aryl rearrangement reactions of 2-heteroaryl/aryloxybenzaldehydes. The protocol was compatible with a variety of functionalities, including methyl, methoxy, cyano, ester, trifluoromethyl, halogen, and heteroaromatic rings. Control experiments suggested that the reaction proceeded via a photoinduced intramolecular heteroaryl/aryl rearrangement process involving photoexcitation of the aldehyde carbonyl group, radical addition, C-C bond formation and C(Ar)-O bond cleavage.

| S-EPMC7425081 | biostudies-literature

Transition Metal-Free Synthesis of Halobenzo[b]furans from O-Aryl Carbamates via o-Lithiation Reactions.

Project description:A straightforward and transition metal-free one-pot protocol to synthesize halobenzo[b]furans has been developed employing simple and easily available starting materials such as O-aryl carbamates and alkynylsulfones. The fine-tuning of the different steps involved was key to achieving a successful one-pot procedure. Initially, a directed ortho-lithiation process, which uses the carbamate as the directed metalation group, was crucial in providing access to O-2-alkynylaryl N,N-diethyl carbamates by a direct alkynylation of the o-lithiated carbamate, with arylsulfonylalkynes as electrophilic reagents. Cyclization of the generated o-alkynylaryl carbamates was successfully accomplished through a strategy involving in situ carbamate alkaline hydrolysis under conventional heating or microwave irradiation, coupled with a subsequent heterocyclization step delivering the desired benzo[b]furans. A wide variety of new halobenzo[b]furans has been synthesized and their utility has been demonstrated by their further transformation.

| S-EPMC8778012 | biostudies-literature

Nickel-Catalyzed Cross-Electrophile Coupling of Aryl Chlorides with Primary Alkyl Chlorides.

Project description:Alkyl chlorides and aryl chlorides are among the most abundant and stable carbon electrophiles. Although their coupling with carbon nucleophiles is well developed, the cross-electrophile coupling of aryl chlorides with alkyl chlorides has remained a challenge. We report here the first general approach to this transformation. The key to productive, selective cross-coupling is the use of a small amount of iodide or bromide along with a recently reported ligand, pyridine-2,6-bis(N-cyanocarboxamidine) (PyBCamCN). The scope of the reaction is demonstrated with 35 examples (63 ± 16% average yield), and we show that the Br- and I- additives act as cocatalysts, generating a low, steady-state concentration of more-reactive alkyl bromide/iodide.

| S-EPMC7418462 | biostudies-literature

A transition-metal-free & diazo-free styrene cyclopropanation.

Project description:An operationally simple and broadly applicable novel cyclopropanation of styrenes using gem-diiodomethyl carbonyl reagents has been developed. Visible-light triggered the photoinduced generation of iodomethyl carbonyl radicals, able to cyclopropanate a wide array of styrenes with excellent chemoselectivity and functional group tolerance. To highlight the utility of our photocyclopropanation, we demonstrated the late-stage functionalization of biomolecule derivatives.

| S-EPMC7017872 | biostudies-literature

The palladium-catalyzed trifluoromethylation of aryl chlorides.

Project description:The trifluoromethyl group can dramatically influence the properties of organic molecules, thereby increasing their applicability as pharmaceuticals, agrochemicals, or building blocks for organic materials. Despite the importance of this substituent, no general method exists for its installment onto functionalized aromatic substrates. Current methods either require the use of harsh reaction conditions or suffer from a limited substrate scope. Here we report the palladium-catalyzed trifluoromethylation of aryl chlorides under mild conditions, allowing the transformation of a wide range of substrates, including heterocycles, in excellent yields. The process tolerates functional groups such as esters, amides, ethers, acetals, nitriles, and tertiary amines and, therefore, should be applicable to late-stage modifications of advanced intermediates. We have also prepared all the putative intermediates in the catalytic cycle and demonstrated their viability in the process.

| S-EPMC3005208 | biostudies-literature

LiCl-Accelerated Multimetallic Cross-Coupling of Aryl Chlorides with Aryl Triflates.

Project description:While the synthesis of biaryls has advanced rapidly in the past decades, cross-Ullman couplings of aryl chlorides, the most abundant aryl electrophiles, have remained elusive. Reported here is the first general cross-Ullman coupling of aryl chlorides with aryl triflates. The selectivity challenge associated with coupling an inert electrophile with a reactive one is overcome using a multimetallic strategy with the appropriate choice of additive. Studies demonstrate that LiCl is essential for effective cross-coupling by accelerating the reduction of Ni(II) to Ni(0) and counteracting autoinhibition of reduction at Zn(0) by Zn(II) salts. The modified conditions tolerate a variety of functional groups on either coupling partner (42 examples), and examples include a three-step synthesis of flurbiprofen.

| S-EPMC6685420 | biostudies-literature

Metal-Free Aryl Cross-Coupling Directed by Traceless Linkers.

Project description:The metal-free, highly selective synthesis of biaryls poses a major challenge in organic synthesis. The scope and mechanism of a promising new approach to (hetero)biaryls by the photochemical fusion of aryl substituents tethered to a traceless sulfonamide linker (photosplicing) are reported. Interrogating photosplicing with varying reaction conditions and comparison of diverse synthetic probes (40 examples, including a suite of heterocycles) showed that the reaction has a surprisingly broad scope and involves neither metals nor radicals. Quantum chemical calculations revealed that the C-C bond is formed by an intramolecular photochemical process that involves an excited singlet state and traversal of a five-membered transition state, and thus consistent ipso-ipso coupling results. These results demonstrate that photosplicing is a unique aryl cross-coupling method in the excited state that can be applied to synthesize a broad range of biaryls.

| S-EPMC6973076 | 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