Heck Reaction Of Aryl Chlorides Research Articles

Nickel‐Catalyzed Asymmetric Reductive Heck Cyclization of Aryl Halides to Afford Indolines

AbstractA nickel‐catalyzed asymmetric reductive Heck reaction of aryl chlorides has been developed that affords substituted indolines with high enantioselectivity. Manganese powder is used as the terminal reductant with water as a proton source. Mechanistically, it is distinct from the palladium‐catalyzed process in that the nickel–carbon bond is converted into a C−H bond to release the product through protonation instead of hydride donation followed by C−H reductive elimination on Pd.

Nickel-Catalyzed Asymmetric Reductive Heck Cyclization of Aryl Halides to Afford Indolines.

A nickel-catalyzed asymmetric reductive Heck reaction of aryl chlorides has been developed that affords substituted indolines with high enantioselectivity. Manganese powder is used as the terminal reductant with water as a proton source. Mechanistically, it is distinct from the palladium-catalyzed process in that the nickel-carbon bond is converted into a C-H bond to release the product through protonation instead of hydride donation followed by C-H reductive elimination on Pd.

Phosphanamine-functionalized magnetic nanoparticles (PAFMNP): an efficient magnetic recyclable ligand for the Pd-catalyzed Heck reaction of chloroarenes

The reaction of MNPs with a phosphanamine-functionalized trimethoxysilyl compound resulted in the production of a novel and efficient magnetic reusable ligand for application in the Heck reaction of aryl chlorides.

Palladium-Catalyzed Heck Reaction of Aryl Chlorides under Mild Conditions Promoted by Organic Ionic Bases

An efficient Pd-catalyzed Heck reaction of aryl chlorides with olefins under mild conditions is described. High yields of products were achieved with n-Bu(4)N(+)OAc(-) as base. Significantly, the temperature of the Heck reaction of diverse nonactivated aryl chlorides can be lowered to 80 °C. The new reaction system can also tolerate a wider range of olefins.

In situ NMR studies of the mechanism of homogeneously and heterogeneously catalysed Heck reactions of aryl chlorides and bromides

This paper presents for the first time detailed NMR investigations of the changes of the palladium coordination sphere for dissolved Pd salts (Pd(OAc)2) and chosen solid, heterogeneous catalysts (Pd(II)/Al2O3, Pd(II)/NaY zeolite) under Heck reaction conditions for the interesting model substrates bromobenzene and chlorobenzene (and styrene as olefin) using catalytic amounts of Pd only. The information obtained from the mechanistic studies led us to new optimized simple “ligand free” catalyst systems and reaction conditions that allow the activation of chlorobenzene in an unexpected manner under relatively mild reaction conditions.

Intramolecular Heck reactions of aryl chlorides with alkynes

Abstract We have developed a reaction that affords the selective preparation of hexahydro-2 H -pyrido[2,1- a ]isoquinoline dienes, allenes, or alkenes via an intramolecular Heck cyclization of an aryl chloride with an alkyne. Tricyclic isoquinoline core structures of this nature are difficult to access by alternative methods. The unsaturated product formed can be partially controlled by choice of ligand and reaction solvent.

Heck Reactions of Aryl Chlorides Catalyzed by Ligand Free Palladium Salts

Palladium acetate has been shown to be a highly active catalyst for Heck reactions of aryl chlorides even in the absence of organic ligands. Bromobenzene can efficiently be coupled in presence of negligible traces of Pd, resulting in the highest TON (4.7 × 107) and TOF (1.2 × 107 h−1) values that have ever been reported for this system up to now.

Pd‐SAPO‐31, an Efficient, Heterogeneous Catalyst for Heck Reactions of Aryl Chlorides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Pd-SAPO-31, an efficient, heterogeneous catalyst for Heck reactions of aryl chlorides

Pd-SAPO-31 exhibits high activity for Heck reactions of aryl chlorides. These catalysts with activities superior to most known solid catalysts can be recovered and reused with negligible loss in activity.

New Palladium Carbene Catalysts for the Heck Reaction of Aryl Chlorides in Ionic Liquids.

The Heck reaction of aryl chlorides was investigated in the presence of defined monocarbenepalladium(0) complexes. Activated and nonactivated aryl chlorides provide the corresponding cinnamic esters and stilbenes in nBu4NBr as a ionic liquid in good to excellent yields.

New palladium carbene catalysts for the Heck reaction of aryl chlorides in ionic liquids.

[reaction: see text] The Heck reaction of aryl chlorides was investigated in the presence of defined monocarbenepalladium(0) complexes. Activated and nonactivated aryl chlorides provide the corresponding cinnamic esters and stilbenes in (n)Bu(4)NBr as a ionic liquid in good to excellent yields.

Heterogeneous Palladium-Catalysed Heck Reaction of Aryl Chlorides and Styrene in Water Under Mild Conditions

The Heck reaction of chlorobenzene and substituted chlorobenzenes with styrene is performed in water using catalytic palladium on carbon. The presence of a reducing agent, a mild base, and a phase-transfer catalyst enhances the reactivity of chloroarenes. Transfer hydrogenation of the stilbene double bond to yield 1,2-diphenylethane is also observed in situ. The competing reactions in this system are haloaryl homocoupling and hydrodehalogenation. The effects of various process parameters on substrate conversion and product selectivity are examined for PhCl and PhBr and the unique role of the reducing agent is discussed. A series of filtration experiments indicate that, in this system, the catalysis is heterogeneous and not due to palladium leaching.

A versatile catalyst for Heck reactions of aryl chlorides and aryl bromides under mild conditions.

In the presence of Cy2NMe, Pd/P(t-Bu)3 serves as an exceptionally mild and versatile catalyst for Heck reactions of aryl chlorides and bromides. A sterically and electronically diverse array of aryl bromides, as well as activated aryl chlorides, couple with a range of mono- and disubstituted olefins at room temperature, furnishing the arylated product with high E/Z stereoselection. The corresponding reactions of a broad spectrum of electron-neutral and electron-rich aryl chlorides proceed at elevated temperature, also with high selectivity. In terms of scope and mildness, Pd/P(t-Bu)3/Cy2NMe represents an advance over previously reported catalysts for these Heck coupling processes.