title: Direct conversion of indoles to 3,3-difluoro-2-oxindoles via electrophilic fluorination.
abstract: 3,3-Difluoro-2-oxindoles can be obtained directly from indoles in moderate yields via electrophilic fluorination using N-fluorobenzenesulfonimide as a mild fluorinating reagent. The presence of tert-butyl hydroperoxide during the reaction, together with additional heating after quenching the reaction with triethylamine, is beneficial to the formation of the desired product.
authors.affiliation: Organic Chemistry, Institute of Chemical and Engineering Sciences (ICES), Agency for Science, Technology and Research (A*STAR), 11 Biopolis Way, The Helios Block, #03-08, Singapore 138667. lim_yee_hwee@ices.a-star.edu.sg
authors.forename: Yee Hwee
authors.initials: YH
authors.lastname: Lim
authors.forename: Qunxiang
authors.initials: Q
authors.lastname: Ong
authors.forename: Hung A
authors.initials: HA
authors.lastname: Duong
authors.forename: Tuan Minh
authors.initials: TM
authors.lastname: Nguyen
authors.forename: Charles W
authors.initials: CW
authors.lastname: Johannes