- Compounds and methods of arylmethylation (benzylation) as protection for alcohol groups during chemical synthesis
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A process for benzylating an alcohol includes mixing 2-benzyloxy-1-methylpyridinium triflate in an aromatic hydrocarbon solvent having a predetermined boiling point; adding an acid scavenger to the mixture; combining the alcohol to be benzylated with the mixture; reacting the alcohol with the 2-benzyloxy-1-methylpyridinium triflate by heating above ambient temperature to generate the benzylated alcohol; and separating the benzylated alcohol from the mixture.
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Page/Page column 4-5; 10
(2010/07/14)
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- Metalation of Phenols. Synthesis of Benzoquinones by the Oxidative Degradation Approach
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In a effort to explore the potential of so-called oxidative degradation approach for the synthesis of quinones, we have investigated the direct metalation of a number of simple phenols such as o- and p-hydroxybenzyl alcohols, benzyl methyl ethers and N,N-dimethylbenzylamines.Apparently, only those phenolic substrates having available both a coordinating group for chelation and an electron-withdrawing group in a 1,3-relationship are efficiently lithiated, by the action of n-BuLi, in a regioselective manner.Those positions on the aromatic nucleus just flanked by a coordinating, or an acid-base, group could be metalated by action of the t-BuLi/THP system, in favorable cases.
- Saa, Jose M.,Llobera, Antonia,Garcia-Raso, Angel,Costa, Antonio,Deya, Pedro M.
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p. 4263 - 4273
(2007/10/02)
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- ON THE METALATION OF PHENOLIC COMPOUNDS: READY ACCESS TO HIGHLY SUBSTITUTED PHENOLS.
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The direct metalation of several p-hydroxybenzylmethyl ethers has been studied.Those substrates possesing an electron-withdrawing group in a 1,3 relationship with the coordinating (-CH2OMe) group underwent regioselective metalation by the action of n-BuLi/THF.Highly substituted phenols can thus be readily prepared.
- Costa, Antonio,Saa, Jose M.
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p. 5551 - 5554
(2007/10/02)
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