Details

Autor(en) / Beteiligte

• Ghosh, Soumen
• Qu, Zheng‐Wang
• Pradhan, Suman
• Ghosh, Avisek
• Grimme, Stefan
• Chatterjee, Indranil

Titel

HFIP‐Assisted Single C−F Bond Activation of Trifluoromethyl Ketones using Visible‐Light Photoredox Catalysis

Ist Teil von

• Angewandte Chemie International Edition, 2022-02, Vol.61 (9), p.e202115272-n/a

Auflage

International ed. in English

Ort / Verlag

Germany: Wiley Subscription Services, Inc

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A visible light photoredox catalytic method for the selective cleavage of single strong C−F bond in trifluoromethyl ketones is reported. Single electron reduction of trifluoromethyl ketones generates difluoromethyl radicals which can be engaged in intermolecular C−C bond formation with N‐methyl‐N‐arylmethacrylamides to furnish fluorine‐containing oxindole derivatives in good yields. The reaction shows excellent chemoselectivity with good functional group tolerance under mild conditions. 1,1,1,3,3,3‐Hexafluoroisopropanol (HFIP) as a solvent plays a critical role for the selective single C−F bond cleavage. High‐level DFT calculations are depicted to shed light on the mechanism. Single and selective C−F bond activation of trifluoromethyl ketones via visible‐light photoredox catalysis is achieved in the presence of HFIP solvent. Trapping of photo‐catalytically generated difluoromethyl radical to acrylamide derivatives furnishes an essential class of difluoromethyl‐containing oxindole scaffolds. A high level of DFT calculations strongly supports our proposed mechanistic pathway for this novel transformation.