- Decarboxylative Suzuki-Miyaura coupling of (hetero)aromatic carboxylic acids using iodine as the terminal oxidant
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A novel methodology for the decarboxylative Suzuki-Miyaura-type coupling has been established. This process uses iodine or a bromine source as both the decarboxylation mediator and the terminal oxidant, thus avoiding the need for stoichiometric amounts of transition metal salts previously required. Our new protocol allows for the construction of valuable biaryl architectures through the coupling of (hetero)aromatic carboxylic acids with arylboronic acids. The scope of this decarboxylative Suzuki reaction has been greatly diversified, allowing for previously inaccessible non-ortho-substituted aromatic acids to undergo this transformation. The procedure also benefits from low catalyst loadings and the absence of stoichiometric transition metal additives.
- Quibell, Jacob M.,Duan, Guojian,Perry, Gregory J.P.,Larrosa, Igor
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supporting information
p. 6445 - 6448
(2019/06/07)
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- Direct ortho Arylation of Anisoles via the Formation of Four-Membered Lithiumcycles/Palladacycles
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We report here our latest discovery on the directed lithiation and palladium-catalyzed arylation of anisoles. During this research, the formation of a four-membered lithiumcycle followed by transmetalation to the corresponding palladacycle has been achieved, which is difficult to be obtained from palladium-catalyzed C-H activation processes. This approach has provided an alternative way of introducing functionalities to arenes such as anisoles, thioanisoles, and anilines. This approach also features an excellent monoselectivity compared with reactions under transition-metal-catalyzed conditions.
- Xiong, Xiaoyu,Zhu, Ranran,Huang, Lin,Chang, Shuqin,Huang, Jianhui
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supporting information
p. 2046 - 2050
(2017/09/13)
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- A mild robust generic protocol for the Suzuki reaction using an air stable catalyst
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A mild but robust procedure has been developed as a first pass generic protocol for the Suzuki-Miyaura reaction. The protocol employs an air stable palladium pre-catalyst at low loading (1 mol %) in aqueous solvent mixtures at moderate temperature using potassium carbonate as base. Under these mild conditions, most aryl bromides will react with sterically and electronically demanding aryl boronic acids to give complete conversion to the product biphenyls in less than 1 h. Aryl chlorides are also fully converted in most cases either under identical conditions in 8-24 h, or in 2 h at elevated temperature. A further advantage of these mild conditions of moderate temperature, weak base and benign solvent is that sensitive functional groups and structural motifs are well tolerated. In addition, the lipophilic biphenyl products are readily isolated after a simple work-up procedure. These generic conditions are ideal for proof of transformation, and as the starting point for development and optimization of a specific process. The discovery and fine-tuning of this generic protocol will be presented, supported extensively by examples to illustrate its scope and utility.
- Moseley, Jonathan D.,Murray, Paul M.,Turp, Edward R.,Tyler, Simon N.G.,Burn, Ross T.
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experimental part
p. 6010 - 6017
(2012/09/21)
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- Palladium-catalysed Grignard cross-coupling using highly concentrated Grignards in methyl-tetrahydrofuran
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The cross-coupling of Grignard reagents at 5 molar concentration in methyl-tetrahydrofuran with no added reaction solvents can be achieved with the appropriate matching of catalyst to substrate, significantly reducing solvent use when compared to a typical protocol in tetrahydrofuran. Me-THF was also used in an improved microwave accelerated synthesis of the [Pd(L)Cl2] pre-catalysts from sodium tetrachloropalladate in very high yield.
- Milton, Edward J.,Clarke, Matthew L.
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supporting information; experimental part
p. 381 - 383
(2010/08/04)
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- Cp2Fe(PR2)2PdCl2 (R = i-Pr, t-Bu) complexes as air-stable catalysts for challenging Suzuki coupling reactions
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(Chemical Equation Presented) The use of Cp2Fe(PR 2)2PdCl2 (R = i-Pr and t-Bu) in Suzuki coupling reactions were illustrated using a high throughput screening approach. The di-tbpfPdCl2 catalyst was shown to be the more active catalyst for unactivated and sterically challenging aryl chlorides. Comparison studies using the commercial catalysts dppfPdCl2, (Ph3P) 2PdCl2, (Cy3P)2PdCl2, DPEPhosPdCl2, dppbPdCl2, dppePdCl2, Pd(t-Bu3P)2, and [Pd-(μ-Br)(t-Bu3P)] 2 were also done for selected cases to demonstrate the superior activities of di-tbpfPdCl2 and di-isoppfPdCl2.
- Colacot, Thomas J.,Shea, Helene A.
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p. 3731 - 3734
(2007/10/03)
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