Synthesis of Catechols from Phenols via Pd-Catalyzed Silanol-Directed C–H Oxygenation
摘要:
A silanol-directed, Pd-catalyzed C-H oxygenation of phenols into catechols is presented. This method is highly site selective and general, as it allows for oxygenation of not only electron-neutral but also electron-poor phenols. This method operates via a silanol-directed acetoxylation, followed by a subsequent acid-catalyzed cyclization reaction into a cyclic silicon protected catechol, A routine desilylation of the silacyle With TBAF uncovers the catechol product:
A silanol-directed, Pd(II)-catalyzed C-H alkenylation of phenols is reported. This work features silanol, as a novel traceless directing group, and a directed o-C-H alkenylation of phenols. This new method allows for efficient synthesis of diverse alkenylated phenols, including an estrone derivative.