Coupling Reactions Of Aryl Halides Research Articles

Copper-free heterogeneous catalysts for the Sonogashira cross-coupling reaction: Preparation, characterisation, activity and applications for organic synthesis

Heterogeneous copper-free catalysts supported on microporous ([Pd(NH 3) 4] 2+/NaY) and mesoporous materials ([Pd]/SBA-15) have been prepared, characterised and evaluated in the Sonogashira coupling reaction of aryl halides with phenyl acetylene. Generally, these catalysts showed high activity and selectivity, somewhat comparable to that of homogeneous catalysts (i.e. {Pd[P( o-C 6H 4CH 3) 2(C 6H 4CH 2)[OCOCH 3]} 2 and PdCl 2(PPh 3) 2). In addition, it was found that the catalyst based on the SBA-15 material (i.e. [Pd]/SBA-15), was particularly active when using large aryl halides such as bromonaphtalene and bromoanthacene, whereas, the heterogeneous catalyst based on microporous support (i.e. [Pd(NH 3) 4] 2+/NaY) was inactive. The recycling of various catalyst and X-ray diffraction and 31P CP-MAS NMR studies of fresh and recycled catalyst are also briefly discussed.

Synthesis of Aryl Sulfones via L‐Proline‐Promoted CuI‐Catalyzed Coupling Reaction of Aryl Halides with Sulfinic Acid Salts.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Pd Nanoparticles as Efficient Catalysts for Suzuki and Stille Coupling Reactions of Aryl Halides in Ionic Liquids

Pd-catalyzed Suzuki and Stille cross-couplings of aryl bromides and chlorides were carried out in quaternary ammonium salts as solvents under mild conditions and with the recycling of the catalyst.

Preparation of N‐Aryl Compounds by Amino Acid‐Promoted Ullmann‐Type Coupling Reactions.

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Use of Tunable Ligands Allows for Intermolecular Pd-Catalyzed C−O Bond Formation

Bulky biaryl phosphine ligands facilitate Pd-catalyzed C-O coupling reactions of aryl halides with primary and secondary alcohols by promoting reductive elimination at the expense of beta-hydride elimination. The key to their success is the ability to match the size of the ligand to that of the combination of substrates. The efficient coupling of a number of unactivated aryl chlorides and bromides with cyclic and acyclic secondary alcohols was achieved. This included the coupling of allylic alcohols for the first time in a Pd-catalyzed coupling process.

The Development of Efficient Catalysts for Palladium‐Catalyzed Coupling Reactions of Aryl Halides

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Tandem Sonogashira Coupling: An Efficient Tool for the Synthesis of Diarylalkynes.

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Synthesis of Aryl Sulfones via l-Proline-Promoted CuI-Catalyzed Coupling Reaction of Aryl Halides with Sulfinic Acid Salts

[reaction: see text] The CuI/L-proline sodium salt catalyzed coupling reaction of aryl halides with sulfinic acid salts readily occurs at 80-95 degrees C in DMSO to give the corresponding aryl sulfones in good to excellent yields. This process is well-tolerated by a wide range of functional groups including hydroxyl, amino, acetanilide, ketone, ester, and nitrile. Using this method, 4-phenylsulfonyl- and 4-methanesulfonyl-substituted L-phenylalanine derivatives are prepared.

Sequential and domino Sonogashira coupling: Efficient tools for the synthesis of diarylalkynes

The Sonogashira coupling reaction of aryl halides with a masked acetylene, leading to the formation of diarylethynes is reviewed. The process is either run in a sequential coupling–deprotection–coupling manner, or sometimes it is carried out in one-pot, a reaction we coined domino coupling. The procedures were also extended to the synthesis of compound libraries.

Air- and Moisture-Stable Cyclopalladated Complexes as Efficient Catalysts for Suzuki-Miyaura Coupling Reaction

A series of cylcopalladated complexes containing a six-membered chelating ring with the general formula [Pd(Cl)(k2N,C-CH2C6H2(Me)2CHNAr)]2 [where Ar = 2,6-(Me)2C6H3− (3a); 2,6-(iPr)2C6H3− (3b)] and the related phosphine-substituted species [PdCl(k2N,C-CH2C6H2(Me)2CHNAr)(PR3)] [Ar = 2,6-(Me)2C6H3−, R = Cy (5a); Ar = 2,6-(iPr)2C6H3, R = Cy (5b); Ar = 2,6-(Me)2C6H3−, R = Ph (5c); Ar = 2,6-(iPr)2C6H3−, R = Ph (5d)] have been synthesized. In addition, an ortho-metalated complex [PdCl(k2N,C-C6H4CHN(2,6-iPr2C6H3))(PCy3)] (7) was prepared by a similar manner. Crystal structures of 3a, 5b,c, and 7 have been determined. The use of these palladium complexes as catalysts for Suzuki−Miyaura coupling reaction of aryl halides with arylboronic acids in ethanol solution was examined. It is found that this series of palladacycles are considerably active under aerobic conditions. Typically, the best activity (TON ≈ 106) is seen with 3a,b in the coupling reaction of aryl bromide with phenylboronic acid. However, a TEM study ...

1,3‐Phenylene‐bis‐(1H)‐tetrazole Pincer Ligand for Palladium‐Catalyzed Suzuki Cross‐Coupling Reactions of Arylhalides with Arylboronic Acids.

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日進月歩パラジウム触媒の化学：こんな反応がパラジウム触媒で

New palladium-catalyzed reactions recently discovered which involve β-carbon elimination and formation of palladacycles as key reactions are surveyed. Arylation of aromatic ring takes place by the reaction of α, α-disubstituted arylmethanols with aryl halides via β-carbon elimination. Novel methods of functionalization of aromatics were discovered by Catellani by the unique palladium and norbornene-catalyzed coupling reactions of aryl halides. Polyarylations of phenols and other aromatic rings with aryl halides proceed smoothly via facile formation of palladacycles due to the participation of OH groups. These reactions proceed via the following interconversion between Pd(0)-Pd(II)-Pd(IV) species.

CuI‐Catalyzed Coupling Reaction of Aryl Halides with Terminal Alkynes in the Absence of Palladium and Phosphine.

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The development of efficient catalysts for palladium-catalyzed coupling reactions of aryl halides

In the mid 1990s, we started a program on the development of more efficient palladium catalysts for the C-C and C-N coupling reactions of aryl halides, especially aryl chlorides. In this contribution, our investigations on new catalyst systems and their application in organic synthesis are summarized.

Tandem Sonogashira Coupling: An Efficient Tool for the Synthesis of Diarylalkynes

[reaction: see text] The tandem Sonogashira coupling reaction of aryl halides provides an efficient method for the synthesis of diarylalkynes. Several aryl halides were coupled with 2-methyl-3-butyn-2-ol as acetylene source in the presence of PdCl2(PPh3)2 and CuI. Following the deprotection of the acetylene moiety in the same pot using a strong base, the Sonogashira coupling of a second aryl halide led to the formation of the appropriate diarylakyne. The established protocoll was successfully extended to the preparation of compound libraries.

Preparation ofN-Aryl Compounds by Amino Acid-Promoted Ullmann-Type Coupling Reactions

N-Aryl α- or β-amino acids, aryl amines, N-arylpyrroles, N-arylindoles, N-arylimidazoles, N-arylpyrazoles and aryl azides are prepared by CuI-catalyzed coupling reactions of aryl halides with corresponding nitrogen sources using amino acids as the promoters.

Synthesis of Aryl Azides and Vinyl Azides via Proline‐Promoted CuI‐Catalyzed Coupling Reactions.

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Comparison of palladium carbene and palladium phosphine catalysts for catalytic coupling reactions of aryl halides

Palladium-catalyzed CC and CN bond forming reactions of aryl halides continue to be a major focus in catalysis research for the fine chemical industry. Still there exists a significant need for the development of more active and productive palladium catalysts. Although an increasing number of new catalysts is reported, it is often difficult to compare them. Here, we present a more detailed comparison of the catalytic performance of different monocarbenepalladium(0) complexes and various so-called in situ palladium phosphine and carbene catalysts in Suzuki, Kumada, and Buchwald–Hartwig amination reactions. Depending on the type of coupling reaction good to excellent yields of the desired products are obtained in the presence of both carbene- and phosphine-based catalysts. In general, phosphine-based catalysts appear to be more efficient for amination and Suzuki reactions of aryl chlorides. On the other hand, the carbene-based palladium catalysts work well in Kumada couplings of various aryl chlorides.

Coupling reactions of aryl bromides with 1-alkynols catalysed by a tetraphosphine/palladium catalyst

cis, cis, cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C 3H 5)] 2 system catalyses efficiently the coupling reactions of aryl halides with a variety of alkynols such as propargyl alcohol, but-1-yn-4-ol, pent-1-yn-5-ol or hex-1-yn-6-ol. The catalyst can be used at low loading. Higher reaction rates were observed in the presence of but-1-yn-4-ol, pent-1-yn-5-ol or hex-1-yn-6-ol than with propargyl alcohol. The protection of the alcohol functions as an ether or a silyloxy group led generally to similar or better results than the reactions performed with the unprotected alcohols.

CuI-catalyzed coupling reaction of aryl halides with terminal alkynes in the absence of palladium and phosphineElectronic supplementary information (ESI) available: Experimental procedures. See http://www.rsc.org/suppdata/cc/b4/b407090a/

CuI/N,N-dimethylglycine-catalyzed coupling reaction of aryl halides with terminal alkynes is carried out in DMF at 100 degrees C to provide the corresponding coupling products in good to excellent yields with a great diversity.