Reductive Coupling Of Aryl Halides Research Articles

Spatially isolated palladium in porous organic polymers by direct knitting for versatile organic transformations

We report here a direct knitting Method for preparation of highly robust, effective while air- and moisture-tolerant, and readily recyclable three-dimensional (3D) porous polymer-Pd network (PPPd) from the widely used Pd(PPh3)4. Electro-beam induced Pd atom crystallization was observed for the first time in organic polymer and revealed the ultrafine dispersion of palladium atoms. Challenging types of Suzuki-Miyaura couplings, reductive coupling of aryl halides and oxidative coupling of arylboronic acid were successively catalyzed by PPPd in aqueous media. Also catalytically selective CH functionalization reactions were achieved with orders of magnitude more efficient than conventional Pd homogeneous catalysts. The strategy developed here provides a practical method for easy-to-make yet highly efficient heterogeneous catalysis.

Corrigendum: Preparation of Vinyl Arenes by Nickel-Catalyzed Reductive Coupling of Aryl Halides with Vinyl Bromides.

In this Communication, the correct affiliation for J. Liu and Dr. X. Zhang should read as follows: School of Chemical and Environmental Engineering Shanghai Institute of Technology 100 Hai-Quan Road, Shanghai 201418 (China) E-mail: xhzhang@sit.edu.cn Furthermore, the original Supporting Information contained some mistakes. A revised version of the Supporting Information is linked to this Corrigendum. The authors apologize for these mistakes.

Berichtigung: Preparation of Vinyl Arenes by Nickel‐Catalyzed Reductive Coupling of Aryl Halides with Vinyl Bromides

In dieser Zuschrift muss die korrekte Adresse für J. Liu und Dr. X. Zhang wie folgt lauten: School of Chemical and Environmental Engineering Shanghai Institute of Technology 100 Hai-Quan Road, Shanghai 201418 (China) E-mail: xhzhang@sit.edu.cn Darüber hinaus enthalten die Hintergrundinformationen einige Fehler, die in der mit dieser Berichtigung verknüpften, revidierten Version korrigiert sind. Die Autoren bitten, diese Fehler zu entschuldigen.

Highly nucleophilic vitamin B12-assisted nickel-catalysed reductive coupling of aryl halides and non-activated alkyl tosylates.

Reductive cross-coupling of aryl halides with ubiquitous alkyl tosylates was developed using a combination of nickel and vitamin B12 (VB12: cyanocobalamin) catalysts. The tosylate was activated by reduced VB12 to form alkyl cobalt(iii), which served as a good alkylating agent for aryl-nickel species, leading to C(sp3)-C(sp2) bond formation.

Preparation of Vinyl Arenes by Nickel-Catalyzed Reductive Coupling of Aryl Halides with Vinyl Bromides.

This work emphasizes the synthesis of substituted vinyl arenes by reductive coupling of aryl halides with vinyl bromides under mild and easy-to-operate nickel-catalyzed reaction conditions. A broad range of aryl halides, including heteroaromatics, and vinyl bromides were employed to yielding products in moderate to excellent yields with high functional-group tolerance. The nickel-catalytic system displays good chemoselectivity between the two C(sp2 )-halide coupling partners, thus demonstrating a mechanistic pathway distinct from other stepwise protocols.

Preparation of Vinyl Arenes by Nickel‐Catalyzed Reductive Coupling of Aryl Halides with Vinyl Bromides

AbstractThis work emphasizes the synthesis of substituted vinyl arenes by reductive coupling of aryl halides with vinyl bromides under mild and easy‐to‐operate nickel‐catalyzed reaction conditions. A broad range of aryl halides, including heteroaromatics, and vinyl bromides were employed to yielding products in moderate to excellent yields with high functional‐group tolerance. The nickel‐catalytic system displays good chemoselectivity between the two C(sp2)‐halide coupling partners, thus demonstrating a mechanistic pathway distinct from other stepwise protocols.

Reductive Ullmann Coupling of Aryl Halides by Palladium Nanoparticles Supported on Cellulose, a Recoverable Heterogeneous Catalyst

Palladium nanoparticles supported on cellulose were prepared without using any reducing agent and used as a highly efficient catalyst for the Ullmann reductive coupling of aryl halides in the presence of zinc, in a water-alcohol mixture as solvent in air. The obtained palladium nanoparticles were characterized by scanning electron microscopy (SEM), FTIR, thermogravimetric analysis (TGA) and ICP-AES analysis. The synthesis of biaryls from chloroarenes was performed by this catalyst with good yield. The catalyst remains stable up to 75 °C and can be recovered and reused several times without loss of activity.

ChemInform Abstract: Nickel‐Catalyzed Reductive Coupling of Aryl Halides with Secondary Alkyl Bromides and Allylic Acetate.

AbstractEfficient methods for the condensation of aryl halides with secondary alkyl bromides and allylic acetate are reported.

Nickel-Catalyzed Reductive Coupling of Aryl Halides with Secondary Alkyl Bromides and Allylic Acetate

A room-temperature Ni-catalyzed reductive method for the coupling of aryl bromides with secondary alkyl bromides has been developed, providing C(sp(2))-C(sp(3)) products in good to excellent yields. Slight modification of this protocol allows efficient coupling of activated aryl chlorides with cyclohexyl bromide and aryl bromides with allylic acetate.

ChemInform Abstract: Ni(II)/Zn Catalyzed Reductive Coupling of Aryl Halides with Diphenylphosphine Oxide in Water.

AbstractMono‐ and bis‐coupling of aryl halides or bis‐substituted aryl halides with diphenylphosphine oxide tolerates a wide range of functional groups.

Ni(II)/Zn Catalyzed Reductive Coupling of Aryl Halides with Diphenylphosphine Oxide in Water

P-Arylation in water has been developed via cross-coupling of aryl halides with diphenylphosphine oxide (Ph(2)P(O)H) and (R(P))-(-)-menthyl benzylphosphinate catalyzed by NiCl(2)·6H(2)O/Zn under relatively mild conditions.

ChemInform Abstract: Electroreductive Generation of Recyclable Organic Reductant from N,N′‐Dioctyl‐4,4′‐bipyridinium and Pd‐Catalyzed Reductive Coupling of Aryl Halides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Electroreductive Generation of Recyclable Organic Reductant from N,N′-Dioctyl-4,4′-bipyridinium and Pd-Catalyzed Reductive Coupling of Aryl Halides

Electroreduction of N, N′-dioctyl-4,4′-bipyridiniumbis(tri-flimide) [C 8 V 2 +][Tf 2 N - ] 2 inTHF gave a dark blue solution of the corresponding quinoid C 8 V 0 ,which worked as an efficient organic reductant for Pd-catalyzedreductive coupling of aryl bromides to give the corresponding biphenylderivatives in good yields. After usual workup, [C 8 V 2 +][Tf 2 N - ] 2 wasrecovered and reused for generation of the organic reductant C 8 V 0 .

Recyclable Electron Transfer System: Viologen/Pd-Promoted Reductive Coupling of Aryl Halides in Ionic Liquid

not Available.

Pd/Viologen-Promoted Reductive Coupling of Aryl Halides in Aqueous Solution

not Available.

Synthesis of functionalised diarylmethanes via a cobalt-catalysed cross-coupling of arylzinc species with benzyl chlorides

A new cobalt-catalysed reductive coupling of aryl halides with benzyl chlorides is reported; a variety of diarylmethanes can be prepared in good to excellent yields under mild reaction conditions using CoBr(2) as catalyst and Zn dust; this new cobalt-catalysed coupling represents a practical and interesting alternative to previously known methods for the synthesis diarylmethanes.

DAB-Cy as an inexpensive and effective ligand for palladium-catalyzed homocoupling reaction of aryl halides

A novel catalytic system of PdCl 2(CH 3CN) 2 with N, N′-dicyclohexyl-1,4-diazabutadiene (DAB-Cy) ligand was successfully used in reductive coupling of aryl halides.

Palladium‐Catalyzed Tetrakis(dimethylamino)ethylene‐Promoted Reductive Coupling of Aryl Halides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Palladium-catalyzed tetrakis(dimethylamino)ethylene-promoted reductive coupling of aryl halides.

Tetrakis(dimethylamino)ethylene (TDAE)/cat. PdCl(2)(PhCN)(2)-promoted reductive coupling of aryl bromides having either electron-donating or electron-withdrawing groups on their para- and/or meta-position proceeded smoothly to afford the corresponding biaryls in good to excellent yields. Notably, TDAE is such a mild reductant that easily reducible groups, such as carbonyl and nitro groups, are tolerate. A similar reductive coupling of ortho-substituted aryl bromides did not occur at all. The proper choice of palladium catalysts is essential for the reductive coupling; thus, PdCl(2)(PhCN)(2), PdCl(2)(MeCN)(2), Pd(hfacac)(2), Pd(2)(dba)(3), PdCl(2), and Pd(OAc)(2) were used successively for this reaction, but phosphine-ligated palladium catalysts such as Pd(PPh(3))(4), PdCl(2)(PPh(3))(2), and Pd(dppp) did not promote the reaction. The reductive coupling did not occur with nickel catalysts such as NiBr(2), NiCl(2)(bpy), and Ni(acac)(2). The TDAE/cat. palladium-promoted reductive coupling of aryl halides having electron-withdrawing groups took place more efficiently than that of aryl halides substituted with electron-donating groups. A plausible mechanism of TDAE/cat. palladium-promoted reaction is discussed.

Carbon—Carbon Bond Formation via Palladium‐Catalyzed Reductive Coupling of Aryl Halides in Air and Water.

Palladium-catalyzed reactions in general are carried out under an inert atmosphere because the palladium intermediates involved in the catalytic cycles are often known to be sensitive to oxygen. In this paper, we report that various palladium-catalyzed reductive couplings proceed smoothly under an air atmosphere and in aqueous medium. Under the air atmosphere reaction conditions, palladium-triphenylphosphine complex was found to be inactive. By using zinc as the reducing reagent, aryl halides were homo-coupled to give symmetrical biaryls either in aqueous acetone or in water in the presence of a catalytic amount of 18-crown-6 at room temperature. Both aryl iodides and aryl bromides reacted efficiently under the current reaction conditions. The reaction of arylhalosilanes with aryl halides under refluxing conditions in air and water catalyzed by palladium generated unsymmetrical biaryls efficiently in the presence of either KOH or NaF. Such air-stable couplings are also suitable for a Suzuki-type coupling and a Stille-type coupling.