Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Non-directed aromatic C-H amination: catalytic and mechanistic studies enabled by Pd catalyst and reagent design.

ABSTRACT: This manuscript describes the systematic development of pyridine-type ligands, which promote the Pd catalyzed, non-directed amination of benzene in combination with novel, hydroxylamine-based electrophilic amination reagents. DFT calculations and mechanistic experiments provide insights into the factors influencing the arene C-H amination protocol.

SUBMITTER: Bandara HM

PROVIDER: S-EPMC5215025 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Non-directed aromatic C-H amination: catalytic and mechanistic studies enabled by Pd catalyst and reagent design.

Bandara H M D HM Jin D D Mantell M A MA Field K D KD Wang A A Narayanan R P RP Deskins N A NA Emmert M H MH

Catalysis science & technology 20160324 14

This manuscript describes the systematic development of pyridine-type ligands, which promote the Pd catalyzed, non-directed amination of benzene in combination with novel, hydroxylamine-based electrophilic amination reagents. DFT calculations and mechanistic experiments provide insights into the factors influencing the arene C-H amination protocol. ...[more]

PMID: 28066540

Similar Datasets

Enantioselective α-Amination Enabled by a BINAM-Derived Phase-Transfer Catalyst.

Project description:Chiral anion phase-transfer of aryldiazonium cations was utilized to achieve highly enantioselective α-amination of carbonyl compounds. A broad scope of indanone- and benzosuberone-derived substrates was amenable to this strategy. Critical to obtaining high levels of enantioselectivity was the use of BINAM-derived phosphoric acids. The utility of this transformation was demonstrated through facile conversion of diazene products to valuable α-amino acid derivatives.

| S-EPMC4251561 | biostudies-literature

Radical C-N Borylation of Aromatic Amines Enabled by a Pyrylium Reagent.

Project description:Herein, we report a radical borylation of aromatic amines through a homolytic C(sp2 )-N bond cleavage. This method capitalizes on a simple and mild activation via a pyrylium reagent (Sc Pyry-OTf) thus priming the amino group for reactivity. The combination of terpyridine and a diboron reagent triggers a radical reaction which cleaves the C(sp2 )-N bond and forges a new C(sp2 )-B bond. The unique non-planar structure of the pyridinium intermediate, provides the necessary driving force for the aryl radical formation. The method permits borylation of a wide variety of aromatic amines indistinctively of the electronic environment.

| S-EPMC7155052 | biostudies-literature

Preparation of Chiral Allenes through Pd-Catalyzed Intermolecular Hydroamination of Conjugated Enynes: Enantioselective Synthesis Enabled by Catalyst Design.

Project description:In this study, we establish that conjugated enynes undergo selective 1,4-hydroamination under Pd catalysis to deliver chiral allenes with pendant allylic amines. Several primary and secondary aliphatic and aryl-substituted amines couple with a wide range of mono- and disubstituted enynes in a nonenantioselective reaction where DPEphos serves as the ligand for Pd. Benzophenone imine acts as an ammonia surrogate to afford primary amines in a two-step/one-pot process. Examination of chiral catalysts revealed a high degree of reversibility in the C-N bond formation that negatively impacted enantioselectivity. Consequently, an electron-poor ferrocenyl-PHOX ligand was developed to enable efficient and enantioselective enyne hydroamination.

| S-EPMC6568270 | biostudies-literature

Electrochemically Enabled, Nickel-Catalyzed Amination.

Project description:Along with amide bond formation, Suzuki cross-coupling, and reductive amination, the Buchwald-Hartwig-Ullmann-type amination of aryl halides stands as one of the most employed reactions in modern medicinal chemistry. The work herein demonstrates the potential of utilizing electrochemistry to provide a complementary avenue to access such critical bonds using an inexpensive nickel catalyst under mild reaction conditions. Of note is the scalability, functional-group tolerance, rapid rate, and the ability to employ a variety of aryl donors (Ar-Cl, Ar-Br, Ar-I, Ar-OTf), amine types (primary and secondary), and even alternative X-H donors (alcohols and amides).

| S-EPMC5792186 | biostudies-literature

Room-Temperature Cu-Catalyzed Amination of Aryl Bromides Enabled by DFT-Guided Ligand Design.

Project description:Ullmann-type C-N coupling reactions represent an important alternative to well-established Pd-catalyzed approaches due to the differing reactivity and the lower cost of Cu. While the design of anionic Cu ligands, particularly those by Ma, has enabled the coupling of various classes of aryl halides and alkyl amines, most methods require conditions that can limit their utility on complex substrates. Herein, we disclose the development of anionic N1,N2-diarylbenzene-1,2-diamine ligands that promote the Cu-catalyzed amination of aryl bromides under mild conditions. Guided by DFT calculations, these ligands were designed to (1) increase the electron density on Cu, thereby increasing the rate of oxidative addition of aryl bromides, and (2) stabilize the active anionic CuI complex via a π-interaction. Under optimized conditions, structurally diverse aryl and heteroaryl bromides and a broad range of alkyl amine nucleophiles, including pharmaceuticals bearing multiple functional groups, were efficiently coupled at room temperature. Combined computational and experimental studies support a mechanism of C-N bond formation that follows a catalytic cycle akin to the well-explored Pd-catalyzed variants. Modification of the ligand structure to include a naphthyl residue resulted in a lower energy barrier to oxidative addition, providing a 30-fold rate increase relative to what is seen with other ligands. Collectively, these results establish a new class of anionic ligands for Cu-catalyzed C-N couplings, which we anticipate may be extended to other Cu-catalyzed C-heteroatom and C-C bond-forming reactions.

| S-EPMC10415864 | biostudies-literature

Ligand-enabled methylene C(sp3)-H bond activation with a Pd(II) catalyst.

Project description:Pd(II) insertion into β-methylene C(sp(3))-H bonds was enabled by a mutually repulsive and electron-rich quinoline ligand. Ligand tuning led to the development of a method that allows for installation of an aryl group on a range of acyclic and cyclic amides containing β-methylene C(sp(3))-H bonds.

| S-EPMC3500088 | biostudies-literature

Pd-catalysed ligand-enabled carboxylate-directed highly regioselective arylation of aliphatic acids.

Project description:?-amino acids bearing aromatic side chains are important synthetic units in the synthesis of peptides and natural products. Although various ?-C-H arylation methodologies for amino acid derivatives involving the assistance of directing groups have been extensively developed, syntheses that directly employ N-protected amino acids as starting materials remain rare. Herein, we report an N-acetylglycine-enabled Pd-catalysed carboxylate-directed ?-C(sp3)-H arylation of aliphatic acids. In this way, various non-natural amino acids can be directly prepared from phthaloylalanine in one step in good to excellent yields. Furthermore, a series of aliphatic acids have been shown to be amenable to this transformation, affording ?-arylated propionic acid derivatives in moderate to good yields. More importantly, this ligand-enabled direct ?-C(sp3)-H arylation could be easily scaled-up to 10?g under reflux conditions, highlighting the potential utility of this synthetic method.

| S-EPMC5384235 | biostudies-literature

Directed amination of non-acidic arene C-H bonds by a copper-silver catalytic system.

Project description:Amine meets arene: A method for direct amination of ?-C(sp(2))-H bonds of benzoic acid derivatives and ?-C(sp(2))-H bonds of benzylamine derivatives has been developed. The reaction is catalyzed by Cu(OAc)2 and a Ag2CO3 cocatalyst, and shows high generality and functional-group tolerance, as well as providing a straightforward means for the preparation of ortho-aminobenzoic acid derivatives.

| S-EPMC3734806 | biostudies-literature

Aromatic C-H amination in hexafluoroisopropanol.

Project description:We report a direct radical aromatic amination reaction that provides unprotected anilines with an improvement in the substrate scope compared to prior art. Hydrogen bonding by the solvent hexafluoroisopropanol to anions of cationic species is responsible for increased reactivity and can rationalize the enhancement in substrate scope. Our findings may have bearings on radical additions to arenes for direct C-H functionalization in general.

| S-EPMC6385662 | biostudies-literature

A Widely Applicable Dual Catalytic System for Cross-Electrophile Coupling Enabled by Mechanistic Studies.

Project description:A dual catalytic system for cross-electrophile coupling reactions between aryl halides and alkyl halides that features a Ni catalyst, a Co cocatalyst, and a mild homogeneous reductant is described. Mechanistic studies indicate that the Ni catalyst activates the aryl halide, while the Co cocatalyst activates the alkyl halide. This allows the system to be rationally optimized for a variety of substrate classes by simply modifying the loadings of the Ni and Co catalysts based on the reaction product profile. For example, the coupling of aryl bromides and aryl iodides with alkyl bromides, alkyl iodides, and benzyl chlorides is demonstrated using the same Ni and Co catalysts under similar reaction conditions but with different optimal catalyst loadings in each case. Our system is tolerant of numerous functional groups and is capable of coupling heteroaryl halides, di-ortho-substituted aryl halides, pharmaceutically relevant druglike aryl halides, and a diverse range of alkyl halides. Additionally, the dual catalytic platform facilitates a series of selective one-pot three-component cross-electrophile coupling reactions of bromo(iodo)arenes with two distinct alkyl halides. This demonstrates the unique level of control that the platform provides and enables the rapid generation of molecular complexity. The system can be readily utilized for a wide range of applications as all reaction components are commercially available, the reaction is scalable, and toxic amide-based solvents are not required. It is anticipated that this strategy, as well as the underlying mechanistic framework, will be generalizable to other cross-electrophile coupling reactions.

| S-EPMC7899151 | 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