BF3·OEt2-Promoted Tandem O-Arylation/Hydroxylation: Efficient Synthesis of 2-Hydroxyflavanones from Triazenylaryl-Substituted Diketones

Graphical Highly substituted 2-hydroxyflavanones can be obtained through a tandem O -arylation/hydroxylation process from triazenylaryl-substituted diketones in the presence of a Lewis acid. A transition-metal-free tandem O -arylation/hydroxylation approach has been developed for the efficient synthesis of highly substituted 2-hydroxyflavanones from triazenylaryl-substituted diketones. The intermediate benzopyrylium cation may be involved in these reactions.