- Improved Cs2CO3 promoted O-alkylation of phenols
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Cesium carbonate mediated O-alkylation of phenols was carried out under mild conditions to give the corresponding phenol ethers exclusively. The methodology is more efficient than previous methods since harsh conditions such as higher temperatures and lon
- Parrish, Jay P.,Sudaresan, Bhuvana,Jung, Kyung Woon
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- Investigating the microwave-accelerated Claisen rearrangement of allyl aryl ethers: Scope of the catalysts, solvents, temperatures, and substrates
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The microwave-accelerated Claisen rearrangement of allyl aryl ethers was investigated, in order to gain insight into the scope of the catalysts, solvents, temperatures, and substrates. Among the catalysts examined, phosphomolybdic acid (PMA) was found to greatly accelerate the reaction in NMP, at temperatures ranging from 220 to 300 °C. This method was found to be useful for preparing several intermediates previously reported in the literature using precious metal catalysts such as Au(I), Ag(I), and Pt(II). Additionally, substrates bearing bromo and nitro groups on the aryl portion required careful tailoring of the reaction conditions to avoid complex product profiles.
- Hui, Zi,Jiang, Songwei,Qi, Xiang,Ye, Xiang-Yang,Xie, Tian
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supporting information
(2020/05/18)
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- Selective Claisen rearrangement and iodination for the synthesis of polyoxygenated allyl phenol derivatives
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Allyl aryl ethers and allyl phenol derivatives were prepared starting from commercial or synthetized phenols. Either Williamson reaction or Et2AlCl catalyzed Claisen rearrangement was performed to obtain the polyoxygenated molecules. The pivotal allyl phenols were then modified by methylation, iodocyclization or electrophilic aromatic iodination to afford the polyoxygenated derivatives in good to excellent yields. Additionally, their antibacterial properties were also investigated against Gram-positive and Gram-negative bacteria.
- Bochicchio, Antonella,Cefola, Rossella,Choppin, Sabine,Colobert, Fran?oise,Di Noia, Maria Antonietta,Funicello, Maria,Hanquet, Gilles,Pisano, Isabella,Todisco, Simona,Chiummiento, Lucia
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supporting information
p. 4053 - 4055
(2016/08/18)
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- Facile construction of the benzofuran and chromene ring systems via Pd II-catalyzed oxidative cyclization
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(Chemical Equation Presented) We herein report the development of one-pot procedures for the conversion of allyl aryl ethers to 2-methylbenzofurans (via sequential Claisen rearrangement and oxidative cyclization) and for the conversion of aryl homoallyl e
- So, Won Youn,Jeong, Im Eom
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p. 3355 - 3358
(2007/10/03)
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- Thermodynamic, spectroscopic, and density functional theory studies of allyl aryl and prop-1-enyl aryl ethers. Part 1. Thermodynamic data of isomerization
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A chemical equilibration study of the relative thermodynamic stabilities of seventy isomeric allyl aryl ethers (a) and (Z)-prop-1-enyl aryl ethers (b) in DMSO solution has been carried out. From the variation of the equilibrium constant with temperature the Gibbs energies, enthalpies, and entropies of isomerization at 298.15 K have been evaluated. Because of their low enthalpies, the (Z)-prop-1-enyl aryl ethers are strongly favored at equilibrium, the Gibbs energies of the a→b isomerization ranging from -12 to -23 kJ mol-1. The entropy contribution is negligible in most reactions, but occasionally small positive values less than +10 J K-1 mol-1 of the entropy of isomerization are found. The equilibration studies were also extended to involve two pairs of related isomeric ethers with a Me substituent on C(2) of the olefinic bond. The Me substituent was found to increase the relative thermodynamic stability of the allylic ethers by ca. 3.4 kJ mol-1.
- Taskinen, Esko
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p. 1824 - 1834
(2007/10/03)
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