title: Asymmetric Desymmetrization via Metal-Free C-F Bond Activation: Synthesis of 3,5-Diaryl-5-fluoromethyloxazolidin-2-ones with Quaternary Carbon Centers.
abstract: We disclose the first asymmetric activation of a non-activated aliphatic C-F bond in which a conceptually new desymmetrization of 1,3-difluorides by silicon-induced selective C-F bond scission is a key step. The combination of a cinchona alkaloid based chiral ammonium bifluoride catalyst and N,O-bis(trimethylsilyl)acetoamide (BSA) as the silicon reagent enabled the efficient catalytic cycle of asymmetric Csp3 -F bond cleavage under mild conditions with high enantioselectivities. The ortho effect of the aryl group at the prostereogenic center is remarkable. This concept was applied for the asymmetric synthesis of promising agrochemical compounds, 3,5-diaryl-5-fluoromethyloxazolidin-2-ones bearing a quaternary carbon center.
authors.affiliation: Department of Nanopharmaceutical Sciences and Department of Frontier Materials, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, 466-8555, Japan.
authors.forename: Junki
authors.initials: J
authors.lastname: Tanaka
authors.affiliation: Department of Nanopharmaceutical Sciences and Department of Frontier Materials, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, 466-8555, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Department of Nanopharmaceutical Sciences and Department of Frontier Materials, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, 466-8555, Japan.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Tokunaga
authors.affiliation: Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany.
authors.forename: Günter
authors.initials: G
authors.lastname: Haufe
authors.affiliation: Department of Nanopharmaceutical Sciences and Department of Frontier Materials, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya, 466-8555, Japan. nozshiba@nitech.ac.jp.
authors.forename: Norio
authors.initials: N
authors.lastname: Shibata
keywords: C-F bond activation; asymmetric synthesis; desymmetrization; fluorine; organocatalysis