title: Ortho-Functionalized Aryltetrazines by Direct Palladium-Catalyzed C-H Halogenation: Application to Fast Electrophilic Fluorination Reactions.
abstract: A general catalyzed direct C-H functionalization of s-tetrazines is reported. Under mild reaction conditions, N-directed ortho-C-H activation of tetrazines allows the introduction of various functional groups, thus forming carbon-heteroatom bonds: C-X (X=I, Br, Cl) and C-O. Based on this methodology, we developed electrophilic mono- and poly-ortho-fluorination of tetrazines. Microwave irradiation was optimized to afford fluorinated s-aryltetrazines, with satisfactory selectivity, within only ten minutes. This work provides an efficient and practical entry for further accessing highly substituted tetrazine derivatives (iodo, bromo, chloro, fluoro, and acetate precursors). It gives access to ortho-functionalized aryltetrazines which are difficult to obtain by classical Pinner-like syntheses.
authors.affiliation: Université de Bourgogne, Institut de Chimie Moléculaire de l'Université de Bourgogne, UMR-CNRS 6302, Université de Bourgogne Franche-Comté (UBFC), 9, avenue Alain Savary, 21078, Dijon, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Testa
authors.affiliation: Université de Bourgogne, Institut de Chimie Moléculaire de l'Université de Bourgogne, UMR-CNRS 6302, Université de Bourgogne Franche-Comté (UBFC), 9, avenue Alain Savary, 21078, Dijon, France.
authors.forename: Élodie
authors.initials: É
authors.lastname: Gigot
authors.affiliation: Université de Bourgogne, Institut de Chimie Moléculaire de l'Université de Bourgogne, UMR-CNRS 6302, Université de Bourgogne Franche-Comté (UBFC), 9, avenue Alain Savary, 21078, Dijon, France.
authors.forename: Semra
authors.initials: S
authors.lastname: Genc
authors.affiliation: Université de Bourgogne, Institut de Chimie Moléculaire de l'Université de Bourgogne, UMR-CNRS 6302, Université de Bourgogne Franche-Comté (UBFC), 9, avenue Alain Savary, 21078, Dijon, France.
authors.forename: Richard
authors.initials: R
authors.lastname: Decréau
authors.affiliation: Université de Bourgogne, Institut de Chimie Moléculaire de l'Université de Bourgogne, UMR-CNRS 6302, Université de Bourgogne Franche-Comté (UBFC), 9, avenue Alain Savary, 21078, Dijon, France. julien.roger@u-bourgogne.fr.
authors.forename: Julien
authors.initials: J
authors.lastname: Roger
authors.affiliation: Université de Bourgogne, Institut de Chimie Moléculaire de l'Université de Bourgogne, UMR-CNRS 6302, Université de Bourgogne Franche-Comté (UBFC), 9, avenue Alain Savary, 21078, Dijon, France. jean-cyrille.hierso@u-bourgogne.fr.|Institut Universitaire de France (IUF), 103 Boulevard Saint Michel, 75005, Paris Cedex, France. jean-cyrille.hierso@u-bourgogne.fr.
authors.forename: Jean-Cyrille
authors.initials: JC
authors.lastname: Hierso
keywords: C−H activation; fluorine; halogenation; heterocycles; palladium