- Copper-Catalyzed Ullmann-Type Coupling and Decarboxylation Cascade of Arylhalides with Malonates to Access α-Aryl Esters
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We have developed a high-efficiency and practical Cu-catalyzed cross-coupling to directly construct versatile α-aryl-esters by utilizing readily available aryl bromides (or chlorides) and malonates. These gram-scale approaches occur with turnovers of up to 1560 and are smoothly conducted by the usage of a low catalyst loading, a new available ligand, and a green solvent. A variety of functional groups are tolerated, and the application occurs with α-aryl-esters to access nonsteroidal anti-inflammatory drugs (NSAIDs) on the gram scale.
- Chen, Fen-Er,Chen, Tao,Cheng, Fei,Huang, Yin-Qiu,Li, Jia-Wei,Xiao, Xiao,Zhou, Chen
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supporting information
(2022/01/04)
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- Iron and manganese catalysts for the selective functionalization of arene C(sp2)-H bonds by carbene insertion
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The first examples of the direct functionalization of non-activated aryl sp2 C-H bonds with ethyl diazoacetate (N2CHCO2Et) catalyzed by Mn- or Fe-based complexes in a completely selective manner are reported, with no formation of the frequently observed cycloheptatriene derivatives through competing Buchner reaction. The best catalysts are FeII or MnII complexes bearing the tetradentate pytacn ligand (pytacn= 1-(2-pyridylmethyl)-4,7-dimethyl-1,4,7-triazacyclononane). When using alkylbenzenes, the alkylic C(sp3)-H bonds of the substituents remained unmodified, thus the reaction being also selective toward functionalization of sp2 C-H bonds. Exclusive catalysis: Iron- and-manganese-based catalysts selectively functionalize the C(sp2)-H bonds of benzene or alkylbenzenes through the formal insertion of the CHCO2Et group from N2CHCO2Et (see scheme). When using alkylbenzenes, the alkylic C(sp3)-H bonds of the substituents remain unmodified.
- Conde, Ana,Sabenya, Gerard,Rodríguez, Mònica,Postils, Verònica,Luis, Josep M.,Díaz-Requejo, M. Mar,Costas, Miquel,Pérez, Pedro J.
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supporting information
p. 6530 - 6534
(2016/06/01)
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- Exclusive aromatic vs aliphatic C-H bond functionalization by carbene insertion with gold-based catalysts
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The direct functionalization of aromatic C-H bonds by carbene insertion from diazo compounds catalyzed by gold complexes with N-heterocyclic ligands is described. The reaction is completely selective toward the C sp2-H bonds, other C sp3-H bonds remaining unreacted. A study with several NHC ligands in Au(I) and Au(III) complexes has been performed. The potential application of this strategy to give profen derivatives has also been explored.
- Rivilla, Ivan,Gomez-Emeterio, B. Pilar,Fructos, Manuel R.,Diaz-Requejo, M. Mar,Perez, Pedro J.
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experimental part
p. 2855 - 2860
(2011/07/08)
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- Synthesis of Ethyl Arylacetates by Means of Friedel-Crafts Reaction of Aromatic Compounds with Ethyl α-Chloro-α-(methylthio)acetate
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Friedel-Crafts reaction of aromatic compounds with ethyl α-chloro-α-(methylthio)acetate (1) gave ethyl α-(methylthio)arylacetates (2), which were readily converted into ethyl arylacetates (3) by reductive desulfurization with Raney nickel or zinc dust-acetic acid.The reactions were applied to the syntheses of ibufenac (5) and alclofenac (6), which are anti-inflammatory agents.
- Tamura, Yasumitsu,Choi, Hong Dae,Shindo, Hirohisa,Ishibashi, Hiroyuki
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p. 915 - 921
(2007/10/02)
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- Introduction of α-(acyl) methylthiomethyl group into the aromatic ring by Friedel-Crafts reaction
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Friedel-Crafts α-(acyl)methylthiomethylations of aromatic compounds with α-ethoxycarbonyl, -acetyl, -benzoyl, and -cyano-α-(methylthio)methyl chlorides are described. The resulted products are easily converted to acylmethylated aromatics such as phenylacetate and phenylacetone by reductive desulfurization.
- Tamura,Shindo,Uenishi,Ishibashi
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p. 2547 - 2548
(2007/10/02)
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