Nickel‐Catalyzed Stereo‐ and Enantioselective Cross‐Coupling of
gem
‐Difluoroalkenes with Carbon Electrophiles by C−F Bond Activation
摘要:
AbstractStereo‐ and enantioselective cross‐electrophile coupling involving C−F bond activation is reported. Treatment of gem‐difluoroalkenes with racemic benzyl electrophiles in the presence of a chiral nickel complex using B2pin2 as a stoichiometric reductant allows the construction of a C(sp2)−C(sp3) bond under mild conditions, affording a broad range of monofluoroalkenes bearing stereogenic allylic centers. Initial mechanistic studies indicate that a radical chain pathway may be operating, wherein the ester group in the gem‐difluoroalkene promotes C−F bond activation through oxidative addition to a Ni species.
Palladium-Catalyzed Defluorinative Alkylation of gem-Difluoroalkenes with Cyclopropanols: Stereoselective Synthesis of γ-Fluorinated γ,δ-Unsaturated Ketones
作者:Lingyu Kong、Wenqing Ti、Aijun Lin、Hequan Yao、Yue Huang、Xuanyi Li
DOI:10.1021/acs.orglett.4c01045
日期:2024.5.3
A palladium-catalyzed defluorinative alkylation of gem-difluoroalkenes with cyclopropylalcohols was developed. A range of γ-fluorinated γ,δ-unsaturated ketones were constructed in good yields with excellent stereoselectivities. In addition, by base-mediated intramolecular nucleophilic vinylic substitution (SNV), the products could be further transformed to 2,5-dimethylenetetrahydrofurans and analogues
开发了钯催化的偕二氟烯烃与环丙醇的脱氟烷基化反应。以良好的产率构建了一系列具有优异立体选择性的 γ-氟化 γ,δ-不饱和酮。此外,通过碱介导的分子内亲核乙烯基取代(S N V),产物可以进一步转化为具有优异立体选择性的2,5-二亚甲基四氢呋喃及其类似物。