Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Rapidly Activating Pd-Precatalyst for Suzuki-Miyaura and Buchwald-Hartwig Couplings of Aryl Esters.

ABSTRACT: Esters are valuable electrophiles for cross-coupling due to their ubiquity and ease of synthesis. However, harsh conditions are traditionally required for the effective cross-coupling of ester substrates. Utilizing a recently discovered precatalyst, Pd-catalyzed Suzuki-Miyaura and Buchwald-Hartwig reactions involving cleavage of the C(acyl)-O bond of aryl esters that proceed under mild conditions are reported. The Pd(II) precatalyst is highly active because it is reduced to the Pd(0) active species more rapidly than previous precatalysts.

SUBMITTER: Dardir AH

PROVIDER: S-EPMC5786428 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Rapidly Activating Pd-Precatalyst for Suzuki-Miyaura and Buchwald-Hartwig Couplings of Aryl Esters.

Dardir Amira H AH Melvin Patrick R PR Davis Ryan M RM Hazari Nilay N Mohadjer Beromi Megan M

The Journal of organic chemistry 20171212 1

Esters are valuable electrophiles for cross-coupling due to their ubiquity and ease of synthesis. However, harsh conditions are traditionally required for the effective cross-coupling of ester substrates. Utilizing a recently discovered precatalyst, Pd-catalyzed Suzuki-Miyaura and Buchwald-Hartwig reactions involving cleavage of the C(acyl)-O bond of aryl esters that proceed under mild conditions are reported. The Pd(II) precatalyst is highly active because it is reduced to the Pd(0) active spec ...[more]

PMID: 29191023

Similar Datasets

Pd-Catalyzed Suzuki-Miyaura and Hiyama-Denmark Couplings of Aryl Sulfamates.

Project description:Using a recently discovered precatalyst, the first Pd-catalyzed Suzuki-Miyaura reactions using aryl sulfamates that occur at room temperature are reported. In complementary work, it is demonstrated that a related precatalyst can facilitate the coupling of aryl silanolates, which are less toxic and reactive nucleophiles than boronic acids with aryl chlorides. By combining our results using modern electrophiles and nucleophiles, the first Hiyama-Denmark reactions using aryl sulfamates are reported.

| S-EPMC5321212 | biostudies-literature

What can reaction databases teach us about Buchwald-Hartwig cross-couplings?

Project description:Despite the widespread and increasing usage of Pd-catalyzed C-N cross couplings, finding good conditions for these reactions can be challenging. Practitioners mostly rely on few methodology studies or anecdotal experience. This is surprising, since the advent of data-driven experimentation and the large amount of knowledge in databases allow for data-driven insight. In this work, we address this by analyzing more than 62 000 Buchwald-Hartwig couplings gathered from CAS, Reaxys and the USPTO. Our meta-analysis of the reaction performance generates data-driven cheatsheets for reaction condition recommendation. It also provides an interactive tool to find rarer ligands with optimal performance regarding user-selected substrate properties. With this we give practitioners promising starting points. Furthermore, we study bias and diversity in the literature and summarize the current state of the reaction data, including its pitfalls. Hence, this work will also be useful for future data-driven developments such as the optimization of reaction conditions via machine learning.

| S-EPMC8378852 | biostudies-literature

Nanonickel-catalyzed Suzuki-Miyaura cross-couplings in water.

Project description:Nickel nanoparticles, formed in?situ and used in combination with micellar catalysis, catalyze Suzuki-Miyaura cross-couplings in water under very mild reaction conditions.

| S-EPMC4677689 | biostudies-literature

Nickel-catalyzed Suzuki-Miyaura couplings in green solvents.

Project description:The nickel-catalyzed Suzuki-Miyaura coupling of aryl halides and phenol-derived substrates with aryl boronic acids using green solvents, such as 2-Me-THF and tert-amyl alcohol, is reported. This methodology employs the commercially available and air-stable precatalyst, NiCl2(PCy3)2, and gives biaryl products in synthetically useful to excellent yields. Using this protocol, bis(heterocyclic) frameworks can be assembled efficiently.

| S-EPMC3768281 | biostudies-literature

Nickel-catalyzed Suzuki-Miyaura cross-couplings of aldehydes.

Project description:Transition-metal-catalyzed cross-couplings have been extensively used in the pharmaceutical and agrochemical industries for the construction of diverse C-C bonds. Conventional cross-coupling reactions require reactive electrophilic coupling partners, such as organohalides or sulfonates, which are not environmentally friendly and not naturally abundant. Another disadvantage associated with these transformations is the need for an exogenous base to facilitate the key transmetalation step, and this reagent inevitably induces side reactions and limits the substrate scope. Here, we report an unconventional Suzuki-type approach to the synthesis of biaryls, through nickel-catalyzed deformylative cross coupling of aldehydes with organoboron reagents under base-free conditions. The transformation tolerates structurally diverse (hetero)aryl substituents on both coupling partners and shows high reactivity and excellent functional group tolerance. Furthermore, the protocol was carried out on gram scale and successfully applied to the functionalization of complex biologically active molecules. Mechanistic investigations support a catalytic cycle involving the oxidative addition of the nickel into the aldehyde C(acyl)-H bond with subsequent hydride transfer, transmetalation, decarbonylation and reductive elimination processes.

| S-EPMC6488620 | biostudies-literature

Application of 6,7-indole aryne cycloaddition and Pd(0)-catalyzed Suzuki-Miyaura and Buchwald-Hartwig cross-coupling reactions for the preparation of annulated indole libraries.

Project description:The construction of an unprecedented class of an indole-based library, namely, a 6,7-annulated-4-substituted 93-member indole library, using a strategic combination of 6,7-indolyne cycloaddition and cross-coupling reactions under both Suzuki-Miyaura and Buchwald-Hartwig conditions is described. This work represents the first example of library development that employs the indole aryne methodology. Annulated indoles, with the exception of only a few biologically active natural products (i.e., the trikentrins, herbindoles, teleocidins, and nodulisporic acids), have no representation in the PubChem or MLSMR databases. These structural entities are therefore predicted to have unique chemical property space characteristics and a high probability of exhibiting interesting biological activity.

| S-EPMC3959986 | biostudies-literature

Application of Suzuki-Miyaura and Buchwald-Hartwig Cross-coupling Reactions to the Preparation of Substituted 1,2,4-Benzotriazine 1-Oxides Related to the Antitumor Agent Tirapazamine.

Project description:Many 1,2,4-benzotriazine 1,4-dioxides display the ability to selectively kill the oxygen-poor cells found in solid tumors. As a result, there is a desire for synthetic routes that afford access to substituted 1,2,4-benzotriazine 1-oxides that can be used as direct precursors in the synthesis of 1,2,4-benzotriazine 1,4-dioxides. Here we describe the use of Suzuki-Miyaura and Buchwald-Hartwig cross-coupling reactions for the construction of various 1,2,4-benzotriazine 1-oxide analogs bearing substituents at the 3-, 6-, and 7-positions.

| S-EPMC5400285 | biostudies-literature

Mechanistic Study of an Improved Ni Precatalyst for Suzuki-Miyaura Reactions of Aryl Sulfamates: Understanding the Role of Ni(I) Species.

Project description:Nickel precatalysts are potentially a more sustainable alternative to traditional palladium precatalysts for the Suzuki-Miyaura coupling reaction. Currently, there is significant interest in Suzuki-Miyaura coupling reactions involving readily accessible phenolic derivatives such as aryl sulfamates, as the sulfamate moiety can act as a directing group for the prefunctionalization of the aromatic backbone of the electrophile prior to cross-coupling. By evaluating complexes in the Ni(0), (I), and (II) oxidation states we report a precatalyst, (dppf)Ni(o-tolyl)(Cl) (dppf = 1,1'-bis(diphenylphosphino)ferrocene), for Suzuki-Miyaura coupling reactions involving aryl sulfamates and boronic acids, which operates at a significantly lower catalyst loading and at milder reaction conditions than other reported systems. In some cases it can even function at room temperature. Mechanistic studies on precatalyst activation and the speciation of nickel during catalysis reveal that Ni(I) species are formed in the catalytic reaction via two different pathways: (i) the precatalyst (dppf)Ni(o-tolyl)(Cl) undergoes comproportionation with the active Ni(0) species; and (ii) the catalytic intermediate (dppf)Ni(Ar)(sulfamate) (Ar = aryl) undergoes comproportionation with the active Ni(0) species. In both cases the formation of Ni(I) is detrimental to catalysis, which is proposed to proceed via a Ni(0)/Ni(II) cycle. DFT calculations are used to support experimental observations and provide insight about the elementary steps involved in reactions directly on the catalytic cycle, as well as off-cycle processes. Our mechanistic investigation provides guidelines for designing even more active nickel catalysts.

| S-EPMC5360380 | biostudies-literature

Pd-Catalyzed Suzuki-Miyaura Cross-Coupling of Pentafluorophenyl Esters.

Project description:Although the palladium-catalyzed Suzuki-Miyaura cross-coupling of aryl esters has received significant attention, there is a lack of methods that utilize cheap and readily accessible Pd-phosphane catalysts, and can be routinely carried out with high cross-coupling selectivity. Herein, we report the first general method for the cross-coupling of pentafluorophenyl esters (pentafluorophenyl = pfp) by selective C?O acyl cleavage. The reaction proceeds efficiently using Pd(0)/phosphane catalyst systems. The unique characteristics of pentafluorophenyl esters are reflected in the fully selective cross-coupling vs. phenolic esters. Of broad synthetic interest, this report establishes pentafluorophenyl esters as new, highly reactive, bench-stable, economical, ester-based, electrophilic acylative reagents via acyl-metal intermediates. Mechanistic studies strongly support a unified reactivity scale of acyl electrophiles by C(O)?X (X = N, O) activation. The reactivity of pfp esters can be correlated with barriers to isomerization around the C(acyl)?O bond.

| S-EPMC6321476 | biostudies-literature

Solvent Effects on the Selectivity of Palladium-Catalyzed Suzuki-Miyaura Couplings.

Project description:The use of polar solvents MeCN or dimethylformamide (DMF) was previously shown to induce a selectivity switch in the Pd/P t Bu3-catalyzed Suzuki-Miyaura coupling of chloroaryl triflates. This phenomenon was attributed to the ability of polar solvents to stabilize anionic transition states for oxidative addition. However, we demonstrate that selectivity in this reaction does not trend with solvent dielectic constant. Unlike MeCN and DMF, water, alcohols, and several polar aprotic solvents such as MeNO2, acetone, and propylene carbonate provide the same selectivity as nonpolar solvents. These results indicate that the role of solvent on the selectivity of Suzuki-Miyaura couplings may be more complex than previously envisioned. Furthermore, this observation has the potential for synthetic value as it greatly broadens the scope of solvents that can be used for chloride-selective cross coupling of chloroaryl triflates.

| S-EPMC7566783 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

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