title: Asymmetric Fluorolactonization with a Bifunctional Hydroxyl Carboxylate Catalyst.
abstract: We report the first successful example of a highly enantioselective fluorolactonization with an electrophilic fluorinating reagent, Selectfluor(®), in the presence of a novel bifunctional organocatalyst. The catalyst design includes a carboxylate anion functioning as a phase-transfer agent and a benzyl alcohol unit to capture the substrate through hydrogen bonding. Fluorinated isobenzofuranones were obtained in good yields with up to 94% ee (97:3 er). On the basis of mechanistic studies, we propose a unique reaction mechanism with potential for further applications.
authors.affiliation: †School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Egami
authors.affiliation: †School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
authors.forename: Junshi
authors.initials: J
authors.lastname: Asada
authors.affiliation: †School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Sato
authors.affiliation: ‡Materials Characterization Support Unit, RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hashizume
authors.affiliation: †School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kawato
authors.affiliation: †School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Hamashima
mesh_terms: D001572:Benzofurans / Q000138:chemical synthesis / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry; D002384:Catalysis; D003979:Diazonium Compounds / Q000737:chemistry; D054879:Halogenation; D006860:Hydrogen Bonding; D007783:Lactones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy
chemical_list: D001572:Benzofurans; D002264:Carboxylic Acids; D003979:Diazonium Compounds; D007783:Lactones; C408750:selectfluor