- Ligand-free highly effective iron/copper co-catalyzed formation of dimeric aryl ethers or sulfides
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Highly selective coupling of diiodoarenes with phenols or phenthiols can be performed by using a low-cost, benign character and readily available Fe/Cu catalytic system in the absence of ligands. It is noteworthy that the desired dimeric aryl ethers or sulfides could be obtained in high yields by coupling between diiodoarenes and phenols, or diphenols with aryl iodides. The Royal Society of Chemistry 2011.
- Qu, Xiaoming,Li, Tingyi,Zhu, Yan,Sun, Peng,Yang, Hailong,Mao, Jincheng
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supporting information; experimental part
p. 5043 - 5046
(2011/08/22)
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- Bis(cyclopentadienyliron)arene Complexes: A new route to the synthesis and functionalization of polyaromatic ethers
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A new development in the chemistry of arenes activated toward SNAr reactions by the cyclopentadienyliron (FeCp+) moiety is presented in this work. A class of diiron complexes of diphenoxybenzenes was prepared in a highly efficient and very mild fashion. Dihydroxy aromatic compounds served as dinucleophiles, allowing for the formation of the diiron complexes. This could be achieved in either a one or two step procedure. A wide variety of dinucleophiles were incorporated into this study, as well as a number of FeCp+ activated arenes. It is shown that these reactions are not inhibited by bulky substituents on either the dinucleophiles or activated arenes. The diiron complexes themselves could also undergo SNAr reactions, provided that the complexed arenes contained a chlorine substituent. This allowed for the functionalization of the complexes with species that could not be introduced directly in their syntheses. The carbon nucleophiles generated from ethyl cyanoacetate or (phenylsulfonyl)acetonitrile could be attached to the complexed ethers in this manner. The FeCp+ moieties were removed easily by photolytic demetalation which allowed for the recovery of a wide range of functionalized diphenoxybenzenes. This methodology is advantageous over all those previously reported and should be a practical route to the synthesis of aromatic ethers.
- Abd-El-Aziz, Alaa S.,Schriemer, David C.,De Denus, Christine R.
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p. 374 - 384
(2008/10/08)
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- PALLADIUM-CATALYSED CYCLISATION OF 2-SUBSTITUTED HALOGENOARENES BY DEHYDROHALOGENATION
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Cyclodehydrohalogenation mediated by various palladium catalysts and solvents with different bases (the most generally satisfactory system being palladium(II) acetate in NN-dimethylacetamide (DMA) with sodium carbonate as base) has been examined as a route to some heterocyclic systems.Whereas dehydrogenative cyclisation processes require stoichiometric amounts of palladium(II) reagent, the present procedure involves only catalytic amounts (0.1 molar proportion, or less), of palladium compound.The preparation of dibenzofuran, carbazole, fluorenone, 6H-dibenzothiazine-5,5-dioxide, 6H-dibenzopyran and benzofuranopyridine derivatives is described.The cyclisation of 3-benzamido-2-chloropyridine to 6-hydroxybenzonaphthiridine illustrates the regiospecificity of the process.
- Ames, D.E.,Opalko, A.
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p. 1919 - 1926
(2007/10/02)
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