- Thieme journal awardees - Where are they now? on cobalt-catalyzed biaryl coupling reactions
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An operationally simple biaryl coupling reaction has been developed. The underlying domino process involves in situ Grignard formation from aryl bromides and subsequent homocoupling with catalytic CoCl2 and 1 bar synthetic air as terminal oxidant. Georg Thieme Verlag Stuttgart.
- Mayer, Matthias,Czaplik, Waldemar Maximilian,Jacobi Von Wangelin, Axel
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- Cross-coupling reactions of arylsilanols with substituted aryl halides
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(Matrix presented) The palladium-catalyzed cross-coupling of arylsilanols with aryl iodides and aryl bromides (in the presence of cesium carbonate) furnished various biaryl products in high yield. An extensive series of optimizations led to the identifica
- Denmark, Scott E.,Ober, Michael H.
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- Palladium-catalyzed cross-coupling reactions of substituted aryl(dimethyl)silanols
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Cesium carbonate and cesium hydroxide monohydrate are effective activators for the palladium-catalyzed cross-coupling of aryl(dimethyl)silanols with substituted aryl halides. Extensive optimization studies led to the identification of key variables (solvent, catalyst, additive, and hydration level) that influence the rate and selectivity of the process. Manipulation of these factors provides an effective coupling method of wide scope and generality. Electron-rich aryl(dimethyl)silanols undergo cross-coupling with aryl iodides and aryl bromides in high yields and high selectivity for the desired cross-coupling products. Alternatively, high yields of cross-coupling products could be obtained with electron-poor or ortho-substituted aryl(dimethyl)silanols when activated with cesium hydroxide monohydrate.
- Denmark, Scott E.,Ober, Michael H.
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- A new palladium catalyzed protocol for atom-efficient cross-coupling reactions of?triarylbismuths with aryl halides and triflates
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A new palladium catalyzed protocol for an atom-efficient cross-coupling reaction of triarylbismuths with aryl halides and triflates has been described. The palladium catalytic system with Cs2CO3 base was found to be very efficient in DMA solvent to furnish excellent yields of cross-coupled functionalized biaryls in short reaction times.
- Rao, Maddali L.N.,Jadhav, Deepak N.,Banerjee, Debasis
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- Nickel(II)/N-Heterocyclic Carbene Catalyzed Desulfinylative Arylation by C?S Cleavage of Aryl Sulfoxides with Phenylboronic Acids
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Suzuki-Miyaura coupling of haloarenes is the most widely used protocol for the synthesis of biphenyls. Organosulfur compounds are promising electrophiles since they are abundant in nature and versatile in organic synthesis. We report here the desulfinylative Suzuki-Miyaura coupling of aryl sulfoxides with phenylboronic acids using bench-stable nickel/5-(2,4,6-triisopropylphenyl)imidazolylidene[1,5-a]pyridines as the catalyst. The ligands are readily prepared from common commercial chemicals. The method is applicable to both symmetric and unsymmetric aryl sulfoxides, and a range of biphenyls bearing various functional groups were obtained in up to 94% yield. (Figure presented.).
- Yi, Xiaowen,Chen, Kai,Guo, Junjun,Chen, Wei,Chen, Wanzhi
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supporting information
p. 4373 - 4377
(2020/07/27)
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- Transition-Metal-Free Oxidative Cross-Coupling of Tetraarylborates to Biaryls Using Organic Oxidants
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Readily prepared tetraarylborates undergo selective (cross)-coupling through oxidation with Bobbitt's salt to give symmetric and unsymmetric biaryls. The organic oxoammonium salt can be used either as a stoichiometric oxidant or as a catalyst in combination with in situ generated NO2 and molecular oxygen as the terminal oxidant. For selected cases, oxidative coupling is also possible with NO2/O2 without any additional nitroxide-based cocatalyst. Transition-metal-free catalytic oxidative ligand cross-coupling of tetraarylborates is unprecedented and the introduced method provides access to various biaryl and heterobiaryl systems.
- Gerleve, Carolin,Studer, Armido
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p. 15468 - 15473
(2020/05/06)
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- Nickel-Catalyzed Decarbonylative Coupling of Aryl Esters and Arylboronic Acids
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A variety of functionalized biaryls can be accessed by coupling aryl and heteroaryl esters with boronic acids in Suzuki-Miyaura-type decarbonylative cross-coupling catalyzed by an affordable catalyst system composed of Ni(cod)2 and PCy3. The methodology is tolerant of a variety of functional groups and presents an attractive alternative to the use of palladium catalysis currently used in industry to acquire such bis(hetero)aryls, but also reveals challenges associated with nickel catalysis of esters in cross-coupling chemistry.
- Laberge, Nicole A.,Love, Jennifer A.
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supporting information
p. 5546 - 5553
(2015/09/01)
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- Iridium-promoted, palladium-catalyzed direct arylation of unactivated arenes
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A Pd-catalyzed cross-coupling reaction between Cp*(PMe 3)IrBn2 and aryl halides was developed. Examining the scope of this reaction led to the discovery that Cp*(PMe 3)IrMeCl activates C-H bonds on arene substrates that undergo subsequent Pd-catalyzed cross-coupling with aryl iodides. This Ir-promoted, Pd-catalyzed direct arylation is notable for its distal selectivity on substituted arenes lacking directing groups or a particular electronic bias.
- Durak, Landon J.,Lewis, Jared C.
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supporting information
p. 620 - 623
(2014/03/21)
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- Platinum-catalyzed C-H arylation of simple arenes
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This report describes the Na2PtCl4 catalyzed C-H arylation of arene substrates with diaryliodonium salts. The site selectivity of these reactions is predominantly controlled by steric factors. Remarkably, Na2PtCl4-catalyzed naphthalene arylation proceeds with opposite site selectivity compared to that obtained with Na2PdCl 4 as the catalyst. Preliminary mechanistic studies provide evidence for a PtII/PtIV catalytic cycle involving rate-limiting C-C bond-forming reductive elimination.
- Wagner, Anna M.,Hickman, Amanda J.,Sanford, Melanie S.
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p. 15710 - 15713
(2013/11/06)
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- Palladium catalyzed Suzuki C-C couplings in an ionic liquid: Nanoparticles responsible for the catalytic activity
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A new family of functionalized ligands derived from norborn-5-ene-2,3- dicarboxylic anhydride has been used in Suzuki C-C cross-couplings between aryl boronic acids and aryl bromide derivatives in [BMI][PF6] (BMI = 1-n-butyl-3-methyl-imidazolium), using palladium acetate as catalytic precursor. High conversions and yields are obtained when amine ligands containing hydroxy groups are involved. TEM analyses after catalysis show the formation of small nanoparticles, in contrast to the agglomerates observed when nanoparticles are intentionally preformed, with a consequent decrease in the catalytic activity in the latter case. Some tests, including the correlation effect between solvent and ligand, are carried out to try to identify the true nature of the catalyst. All the results obtained suggest that formation of nanoparticles is required to lead to a catalytically active system. The Royal Society of Chemistry.
- Fernandez, Fernando,Cordero, Beatriz,Durand, Jerome,Muller, Guillermo,Malbosc, Franois,Kihn, Yolande,Teuma, Emmanuelle,Gomez, Montserrat
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p. 5572 - 5581
(2008/09/17)
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- Phosphine oxides as stabilizing ligands for the palladium-catalyzed cross-coupling of potassium aryldimethylsilanolates
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The palladium-catalyzed cross-coupling reaction of potassium (4-methoxyphenyl)dimethylsilanolate (K+1-) with aryl bromides has been demonstrated using triphenylphosphine oxide as a stabilizing ligand. Unsymmetrical biaryls can be prepared from a variety of aryl bromides in good yield with short reaction times. Qualitative kinetic studies compared effects of different phosphine oxides on the rate of cross-coupling and established the beneficial effect of these ligands in the reaction of electron-rich arylsilanolates. The improved yield and reproducibility of the cross-coupling of several bromides was demonstrated by direct comparison of reactions performed with and without triphenylphosphine oxide under non-rigorous exclusion of oxygen.
- Denmark, Scott E.,Smith, Russell C.,Tymonko, Steven A.
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p. 5730 - 5738
(2008/02/07)
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- Synthese de biaryles dissymetriques par electroreduction d'halogenures aromatiques catalysee par des complexes du nickel associe a la 2,2'-bipyridine
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Nickel-2,2'-bipyridine complexes are useful catalysts in the preparation of unsymmetrical biaryls by electroreduction of a mixture of two aryl halides which are para-substituted with electron acceptors and electron donors, respectively.The syntheses were carried out in N-methylpyrrolidone by constant current electrolyses in an undivided cell fitted with a sacrificial magnesium anode.
- Meyer, Gilbert,Troupel, Michel,Perichon, Jacques
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p. 137 - 142
(2007/10/02)
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- Mesomorphic Properties of Some New Fluorinated Liquid Crystals: the 4-n-Alkoxyperfluorobenzoate Series and Trifluoromethylbiphenyl Derivatives
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We describe here the synthesis, the mesomorphic and the dielectric properties of two families of fluorinated compounds: the 4-alkoxyperfluorobenzoic acid 4'-hydroxy-4-cyanobiphenyl esters and the 4-trifluoromethyl-4'-substituted biphenyl derivatives.Some compounds exhibit only a wide temperature nematic range, while others have a wide temperature smectic A range with or without a nematic mesophase.These compounds are possible additives to mixtures of interest for displays.
- Barny, P. le,Ravaux, G.,Dubois, J. C.,Parneix, J. P.
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p. 413 - 430
(2007/10/02)
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