551930-88-2Relevant academic research and scientific papers
Metal-free oxidative coupling: Xanthone formation via direct annulation of 2-aryloxybenzaldehyde using tetrabutylammonium bromide as a promoter in aqueous medium
Rao, Honghua,Ma, Xinyi,Liu, Qianzi,Li, Zhongfeng,Cao, Shengli,Li, Chao-Jun
, p. 2191 - 2196 (2013)
A metal-free intramolecular annulation of 2-aryloxybenzaldehydes to xanthones is disclosed, which proceeds through the direct oxidative coupling of an aldehyde C-H bond and aromatic C-H bonds using tetrabutylammonium bromide (TBAB) as a promoter in aqueous medium. This strategy works smoothly in the presence of both electron-donating and electron-withdrawing groups, and displays good tolerance towards catalytically reactive substituents, thus promising further functionalizations of xanthone products.
