Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A Zinc Catalyzed C(sp³ )-C(sp² ) Suzuki-Miyaura Cross-Coupling Reaction Mediated by Aryl-Zincates.

ABSTRACT: The Suzuki-Miyaura (SM) reaction is one of the most important methods for C-C bond formation in chemical synthesis. In this communication, we show for the first time that the low toxicity, inexpensive element zinc is able to catalyze SM reactions. The cross-coupling of benzyl bromides with aryl borates is catalyzed by ZnBr₂ , in a process that is free from added ligand, and is compatible with a range of functionalized benzyl bromides and arylboronic acid pinacol esters. Initial mechanistic investigations indicate that the selective in situ formation of triaryl zincates is crucial to promote selective cross-coupling reactivity, which is facilitated by employing an arylborate of optimal nucleophilicity.

SUBMITTER: Procter RJ

PROVIDER: S-EPMC5915750 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

A Zinc Catalyzed C(sp3 )-C(sp2 ) Suzuki-Miyaura Cross-Coupling Reaction Mediated by Aryl-Zincates.

Procter Richard J RJ Dunsford Jay J JJ Rushworth Philip J PJ Hulcoop David G DG Layfield Richard A RA Ingleson Michael J MJ

Chemistry (Weinheim an der Bergstrasse, Germany) 20171019 63

The Suzuki-Miyaura (SM) reaction is one of the most important methods for C-C bond formation in chemical synthesis. In this communication, we show for the first time that the low toxicity, inexpensive element zinc is able to catalyze SM reactions. The cross-coupling of benzyl bromides with aryl borates is catalyzed by ZnBr2 , in a process that is free from added ligand, and is compatible with a range of functionalized benzyl bromides and arylboronic acid pinacol esters. Initial mechan ...[more]

PMID: 28960610

Similar Datasets

Cobalt-Catalyzed C(sp2)-C(sp3) Suzuki-Miyaura Cross Coupling.

Project description:A cobalt-catalyzed method for the C(sp2)-C(sp3) Suzuki-Miyaura cross coupling of aryl boronic esters and alkyl bromides is described. Cobalt-ligand combinations were assayed with high-throughput experimentation, and cobalt(II) sources with trans-N,N'-dimethylcyclohexane-1,2-diamine (DMCyDA, L1) produced optimal yield and selectivity. The scope of this transformation encompassed steric and electronic diversity on the aryl boronate nucleophile as well as various levels of branching and synthetically valuable functionality on the electrophile. Radical trap experiments support the formation of electrophile-derived radicals during catalysis.

| S-EPMC7867578 | biostudies-literature

Ligand-controlled palladium-catalyzed regiodivergent Suzuki-Miyaura cross-coupling of allylboronates and aryl halides.

Project description:An orthogonal set of catalyst systems has been developed for the Suzuki-Miyaura coupling of 3,3-disubstituted and 3-monosubstituted allylboronates with (hetero)aryl halides. These methods allow for the highly selective preparation of either the ?- or the ?-isomeric coupling product.

| S-EPMC3776608 | biostudies-literature

Reaction scope and mechanistic insights of nickel-catalyzed migratory Suzuki-Miyaura cross-coupling.

Project description:Cross-coupling reactions have developed into powerful approaches for carbon-carbon bond formation. In this work, a Ni-catalyzed migratory Suzuki-Miyaura cross-coupling featuring high benzylic or allylic selectivity has been developed. With this method, unactivated alkyl electrophiles and aryl or vinyl boronic acids can be efficiently transferred to diarylalkane or allylbenzene derivatives under mild conditions. Importantly, unactivated alkyl chlorides can also be successfully used as the coupling partners. To demonstrate the applicability of this method, we showcase that this strategy can serve as a platform for the synthesis of terminal, partially deuterium-labeled molecules from readily accessible starting materials. Experimental studies suggest that migratory cross-coupling products are generated from Ni(0/II) catalytic cycle. Theoretical calculations indicate that the chain-walking occurs at a neutral nickel complex rather than a cationic one. In addition, the original-site cross-coupling products can be obtained by alternating the ligand, wherein the formation of the products has been rationalized by a radical chain process.

| S-EPMC6972863 | biostudies-literature

Copper(i)-catalyzed sulfonylative Suzuki-Miyaura cross-coupling.

Project description:Using a simple copper(i) catalyst has allowed a high yielding sulfonylative-Suzuki-Miyaura cross-coupling reaction to be developed. The process provides a single step route to diaryl sulfones from the direct combination of aryl boronic acids, sulfur dioxide and aryl iodides, and represents the first sulfonylative variant of a classic cross-coupling reaction. Sulfur dioxide is delivered from the surrogate reagent, DABSO. Variation of the reaction conditions allowed interruption of the sulfonylative-Suzuki coupling, resulting in the formation of a presumed Cu-sulfinate intermediate. These sulfinates could be trapped as their sodium salts and treated with electrophiles to allow access to arylalkyl sulfones, β-hydroxyl sulfones, sulfonamides and sulfonyl fluorides.

| S-EPMC5424447 | 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

Cobalt-Catalyzed C(sp2)-C(sp3) Suzuki-Miyaura Cross-Coupling Enabled by Well-Defined Precatalysts with L,X-Type Ligands.

Project description:Cobalt(II) halides in combination with phenoxy-imine (FI) ligands generated efficient precatalysts in situ for the C(sp2)-C(sp3) Suzuki-Miyaura cross coupling between alkyl bromides and neopentylglycol (hetero)arylboronic esters. The protocol enabled efficient C-C bond formation with a host of nucleophiles and electrophiles (36 examples, 34-95%) with precatalyst loadings of 5 mol%. Studies with alkyl halide electrophiles that function as radical clocks support the intermediacy of alkyl radicals during the course of the catalytic reaction. The improved performance of the FI-cobalt catalyst was correlated with decreased lifetimes of cage-escaped radicals as compared to diamine-type ligands. Studies of the phenoxy(imine)-cobalt coordination chemistry validate the L,X interaction leading to the discovery of an optimal, well defined, air-stable mono-FI cobalt(II) precatalyst structure.

| S-EPMC9400687 | biostudies-literature

Insight into Transmetalation Enables Cobalt-Catalyzed Suzuki-Miyaura Cross Coupling.

Project description:Among the fundamental transformations that comprise a catalytic cycle for cross coupling, transmetalation from the nucleophile to the metal catalyst is perhaps the least understood. Optimizing this elementary step has enabled the first example of a cobalt-catalyzed Suzuki-Miyaura cross coupling between aryl triflate electrophiles and heteroaryl boron nucleophiles. Key to this discovery was the preparation and characterization of a new class of tetrahedral, high-spin bis(phosphino)pyridine cobalt(I) alkoxide and aryloxide complexes, (iPrPNP)CoOR, and optimizing their reactivity with 2-benzofuranylBPin (Pin = pinacolate). Cobalt compounds with small alkoxide substituents such as R = methyl and ethyl underwent swift transmetalation at 23 °C but also proved kinetically unstable toward β-H elimination. Secondary alkoxides such as R = iPr or CH(Ph)Me balanced stability and reactivity. Isolation and structural characterization of the product following transmetalation, (iPrPNP)Co(2-benzofuranyl), established a planar, diamagnetic cobalt(I) complex, demonstrating the high- and low-spin states of cobalt(I) rapidly interconvert during this reaction. The insights from the studies in this elementary step guided selection of appropriate reaction conditions to enable the first examples of cobalt-catalyzed C-C bond formation between neutral boron nucleophiles and aryl triflate electrophiles, and a model for the successful transmetalation reactivity is proposed.

| S-EPMC5200927 | biostudies-literature

DNA-Compatible Suzuki-Miyaura Cross-Coupling Reaction of Aryl Iodides With (Hetero)Aryl Boronic Acids for DNA-Encoded Libraries.

Project description:An efficient method for the C-C bond formation via water soluble Na2PdCl4/sSPhos mediated Suzuki-Miyaura cross-coupling reaction of DNA-conjugated aryl iodide with (het)aryl boronic acids has been developed. This reaction proceeds at 37°C in water and acetonitrile (4:1) system. We also demonstrated that numerous aromatic and heteroaromatic boronic acids of different electronic natures, and harboring various functional groups, were highly compatible providing the desired coupling products in good to excellent yields. This DNA-compatible Suzuki-Miyaura cross-coupling reaction has strong potential to construct DNA-Encoded Libraries (DELs) in the context of drug discovery.

| S-EPMC9237475 | biostudies-literature

Suzuki-Miyaura cross-coupling reactions of primary alkyltrifluoroborates with aryl chlorides.

Project description:Parallel microscale experimentation was used to develop general conditions for the Suzuki-Miyaura cross-coupling of diversely functionalized primary alkyltrifluoroborates with a variety of aryl chlorides. These conditions were found to be amenable to coupling with aryl bromides, iodides, and triflates as well. The conditions that were previously identified through similar techniques to promote the cross-coupling of secondary alkyltrifluoroborates with aryl chlorides were not optimal for the primary alkyltrifluoroborates, thus demonstrating the value of parallel experimentation to develop novel, substrate specific results.

| S-EPMC2696385 | biostudies-literature

Suzuki-Miyaura cross-coupling of potassium dioxolanylethyltrifluoroborate and aryl/heteroaryl chlorides.

Project description:A robust and efficient protocol for the introduction of the dioxolanylethyl moiety onto various aryl and heteroaryl halides has been developed, providing cross-coupling yields up to 93%. Copper-catalyzed borylation of 2-(2-bromoethyl)-1,3-dioxolane with bis(pinacolato)diboron followed by treatment with potassium bifluoride provides the key organotrifluoroborate reagent.

| S-EPMC3663905 | biostudies-literature