title: CBr4promoted intramolecular aerobic oxidative dehydrogenative arylation of aldehydes: application in the synthesis of xanthones and fluorenones.
abstract: A simple and practical carbon tetrabromide promoted intramolecular aerobic oxidative dehydrogenative coupling reaction has been developed to provide a straightforward ring closure protocol for 2-aryloxybenzaldehydes to furnish xanthones. The reaction was performed under metal-, additive- and solvent-free conditions with good tolerance of functional groups. The present method is also applicable to the synthesis of fluorenones by using 2-arylbenzaldehydes as substrates. Preliminary studies of the reaction mechanism indicated that the reaction may proceed through a radical pathway.
authors.affiliation: College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, China. huocongde1978@hotmail.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Tang
authors.forename: Shijun
authors.initials: S
authors.lastname: Zhao
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wei
authors.forename: Zhengjun
authors.initials: Z
authors.lastname: Quan
authors.forename: Congde
authors.initials: C
authors.lastname: Huo