Metalation of Phenols. Synthesis of Benzoquinones by the Oxidative Degradation Approach

Article abstract of DOI:10.1021/jo00253a019

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.