73087-55-5Relevant academic research and scientific papers
Zirconium-catalyzed Nagata reaction for the synthesis of 2-aryl-1,3,2-aryldioxaborins via a mild three-component condensation of phenols, aldehydes, and boronic acid
Zheng, Hongchao,Hall, Dennis G.
supporting information; experimental part, p. 4256 - 4259 (2010/09/07)
An efficient ZrCl4-catalyzed ortho-hydroxyalkylation of phenols with aldehydes promoted by 3,5-bis(trifluoromethyl)phenyl boronic acid, leading to the formation of 2-aryl-1,3,2-aryldioxaborins, was investigated and optimized. The reaction afforded the desired aryldioxaborins in good to excellent yields under mild conditions at room temperature. The electron-deficient boronic acid promoter was essential. Electron-rich phenols react faster, and both alkyl and aryl aldehydes are suitable substrates. The resulting aryldioxaborins can be further elaborated to produce substituted saligenols, 2-ethoxy chromans, and 2-substituted phenols.
Intramolecular Alkylation of Phenols. Part 5. A Regiospecific Anionic Ring Closure of Phenols via Quinone Methides
Murphy, William S.,Wattanasin, Sompong
, p. 1567 - 1577 (2007/10/02)
The bis-magnesium salts of the triols (6a) and (6h) cyclise when heated in benzene with high ortho-regiospecificity to the corresponding bis-phenols (7) and (8).The triols (6k) and (6o) under the same conditions cyclise with high para-regiospecificity to the corresponding bis-phenols (7) and (8).Both (6a) and (6h) cyclise via o-quinone methides, and (6k) and (6o) via p-quinone methides.Results from the use of, inter alia, 18-crown-6, indicate that the high ortho-regiospecificity of the cyclisation of (6a) and (6h) is due to intramolecular Mg(II) bridging of the intermediate o-quinone methides.The high para-regiospecificity of cyclisation of (6k) and (6o) is due to steric hindrance towards o-cyclisation of the intermediate p-quinone methides presented by the Mg(II) cation.The unexpected facility with which (6a) and (6k) undergo ring closure is discussed.
