Copper(I)-catalyzed Stereoselective Defluoroborylation of Aliphatic <i>Gem</i>-Difluoroalkenes
作者:Hajime Ito、Tamae Seo、Ryoto Kojima、Koji Kubota
DOI:10.1246/cl.180656
日期:2018.10.5
This study reports a method for the stereoselective copper(I)-catalyzed defluoroborylation of aliphatic gem-difluoroalkenes to afford (Z)-monofluoro-substituted borylalkenes. Gem-difluoroalkenes bearing a variety of functional groups were efficiently borylated with high stereoselectivity. A theoretical study of the reaction mechanism is also described.
Coupling of Trifluoroacetaldehyde <i>N</i>-Triftosylhydrazone with Organoboronic Acids for the Synthesis of <i>gem</i>-Difluoroalkenes
作者:Yu Ma、Bhoomireddy Rajendra Prasad Reddy、Xihe Bi
DOI:10.1021/acs.orglett.9b03740
日期:2019.12.20
synthesis of alkyl gem-difluoroalkenes remains a difficult task in organic synthesis. Here, we report a general and efficient approach for tackling this problem by gem-difluoroolefination of trifluoroacetaldehyde N-triftosylhydrazone with organoboronic acids. This protocol is operationally simple, free of transition metals, and suitable for a broad range of organoboronic acids. Moreover, the utility
Silylium Ion Initiated Intramolecular Friedel–Crafts-Type Cyclization of 1,1-Difluoroalkenes with Subsequent Hydrodefluorination of C(sp3)–F Bonds
作者:Avijit Roy、Haopeng Gao、Martin Oestreich、Hendrik F. T. Klare
DOI:10.1055/a-2009-8114
日期:——
reaction is presumed to be initiated by a preferential electrophilic silylation of the carbon–carbon double bond over the activation of one of the vinylic C(sp2)–Fbonds. Subsequent cyclization followed by hydrodefluorination of the resulting C(sp3)–Fbonds leads to the final product. The resulting tetraline derivatives were obtained in moderate to good yields. Distinct from earlier reports, the reaction