Visible-Light-Induced Trifluoromethylation of<i>N</i>-Aryl Acrylamides: A Convenient and Effective Method To Synthesize CF<sub>3</sub>-Containing Oxindoles Bearing a Quaternary Carbon Center
Trifluoromethylation/arylation: N‐aryl acrylamides undergo visible‐light‐induced tandem trifluoromethylation/arylation in the presence of a ruthenium photocatalyst with Togni's reagent as the CF3 source (see scheme). This reaction serves as a powerful and ecofriendly synthetic method for the preparation of a variety of CF3‐containing oxindolesbearing a quaternarycarboncenter.
Decarboxylative Synthesis of Functionalized Oxindoles via An Iron-Initiated Radical Chain Process and Application in Constructing Diverse Fused-Indoline Heterocycles
作者:Zhihao Cui、Da-Ming Du
DOI:10.1002/adsc.201700976
日期:2018.1.4
Rapid construction of diverse fused‐indoline−heterocycle (FIH) frameworks including high‐value pyrroloindolines, furoindolines and thienoindolines in a two‐step sequence has been described. The key to success hinges on the adoption of peresters as α‐heteroatom alkyl radical precusors, which can smoothly react with N‐arylacrylamides via a radical chain process initiated by inexpensive FeCl2⋅4H2O to
An elegant approach to quaternary oxindole formation has been developed through a room temperature decarboxylation/radical CâH functionalization by visible-light photoredox catalysis.