Difluorocarbene‐Induced Ring‐Opening Difluoromethylation‐Halogenation of Cyclic (Thio)Ethers with TMSCF<sub>2</sub>X (X=Br, Cl)**
Rongyi Zhang, Qigang Li, Qiqiang Xie, Chuanfa Ni, Jinbo Hu
Abstract
Abstract The ring‐opening difluoromethylation‐halogenation of cyclic (thio)ethers is reported through a simple strategy relying on carbon‐chalcogen bond activation with difluorocarbene. The reaction proceeds through in situ protonation of the previously little‐known difluoromethylene oxonium or sulfonium ylide intermediate followed by ring‐opening with halide ion to afford halogenated acyclic difluoromethyl (thio)ethers that can then be employed for further elaboration. TMSCF 2 X (X=Br, Cl) are unique reagents to achieve this synthetic purpose, which serve as both the difluorocarbene source and the halide ion source.
Topics & Concepts
DifluorocarbeneOxonium ionYlideSulfoniumHalogenationRing (chemistry)ChemistryMedicinal chemistryCyclopropaneThio-CarbeneProtonationHalideOrganic chemistryIonCatalysisSalt (chemistry)Fluorine in Organic ChemistryCyclopropane Reaction MechanismsCatalytic C–H Functionalization Methods