Radical 1,4/5‐Amino Shift Enables Access to Fluoroalkyl‐Containing Primary β(γ)‐Aminoketones under Metal‐Free Conditions
Dian Wei, Tuming Liu, Yiheng He, Bang‐Yi Wei, Jiahao Pan, Jianwu Zhang, Ning Jiao, Bing Han
Abstract
A novel radical 1,4/5-amino shift from the oxygen center of alkene-tethered diphenyl ketoxime ethers to the carbon center to achieve high value-added fluoroalkyl-containing primary β(γ)-amino-ketones is reported. Mechanism studies reveal that the migration is triggered by the alkene addition of fluoroalkyl radical derived from the electron donor-acceptor (EDA) complex of Togni's reagent II or fluoroalkyl iodides and quinuclidine, and involves a unique 5(6)-exo-trig cyclization of the carbon-centered radical onto the N-atom of ketoxime ethers followed by a cascade sequence of N-O bond cleavage and dehydrogenation. Notably, besides Togni's reagent II and fluoroalkyl iodides, this protocol is also compatible with other radical precursors to provide various functionalized primary aminoketones.