Ab initio study of the mechanism of the formation of p-rosolic acid from trifluoromethoxybenzene under HF/Lewis acid conditions

作者：Belter Randolph K^*; McFerrin Cheri A

来源：Journal of Fluorine Chemistry, 2010, 131(12): 1308-1313.

DOI：10.1016/j.jfluchem.2010.08.004

• Trifluoromethoxy benzene
• p-Rosolic acid
• Fries rearrangement
• Lewis acid catalysis
• Friedel-Crafts

The mechanism of the formation of p-rosolic acid from trifluoromethoxybenzene under HF/Lewis acid conditions was studied using ab initio methods. A series of cationic intermediates is initiated by the expulsion of a fluorine atom of trifluoromethoxybenzene with anomeric assistance of the trifluoromethoxy oxygen. The resulting difluorocarbonium ion is attacked by a second trifluoromethoxybenzene to generate the first carbon-carbon bond on what will be the central carbon of p-rosolic acid. Elimination of phenol results in the formation of cationic intermediate 4 which is susceptible to carbon-alkylation by the same phenol to form the second carbon-carbon bond. Attack on subsequent difluorocarbonium ions by trifluoromethoxybenzene strips trifluoromethyl groups from the downstream intermediates, eventually leading to p-rosolic acid, and continues the generation of 4, each of which initiate a fresh mechanistic series toward another p-rosolic acid molecule.

• 出版日期2010-12