title: Friedel-Crafts Coupling of Electron-Deficient Benzoylacetones Tuned by Remote Electronic Effects.
abstract: Acid-catalyzed electrophilic aromatic substitution for C-C bond formation, commonly referred to as the Friedel-Crafts reaction in recognition of its discoverers, has been one of the most useful reactions in organic chemistry for over a century. However, the Friedel-Crafts reaction cannot occur on a benzene ring having a strongly electron withdrawing group, such as an acyl group, which deactivates the aromatic ring toward electrophilic substitutions and remains a major challenge. Herein, the synthesis of naphthoquinones and 1,3-indandiones, bearing two acyl groups at positions ortho to each other on a benzene ring, are demonstrated by means of copper-catalyzed intramolecular aerobic oxidative acylation of benzoylacetone derivative precursors. This unusual Friedel-Crafts reaction reveals a new activation mode for the in situ polarity reverse of an electron-deficient aromatic ring to a reactive, electron-rich ring tuned by remote electronic effects.
authors.affiliation: Department of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun 130024, People's Republic of China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Luo
authors.affiliation: Department of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun 130024, People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Pan
authors.affiliation: Department of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun 130024, People's Republic of China.
authors.forename: Xianxiu
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun 130024, People's Republic of China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Liu