Facile Entry to Pharmaceutically Important 3-Difluoromethyl-quinoxalin-2-ones Enabled by Visible-Light-Driven Difluoromethylation of Quinoxalin-2-ones.

CFH moiety has a significant potential utility in drug design and discovery, and the incorporation of CFH into biologically active molecules represents an important and efficient strategy for seeking lead compounds and drug candidates. On the other hand, quinoxalin-2-one is of great interest to pharmaceutical chemists as a common skeleton frequently occurring in plenty of natural products and bioactive compounds. Herein, we reported a practical and efficient protocol for the synthesis of 3-CFH-quinoxalin-2-ones.

Difluoromethyl Radical Triggered Tandem Reaction of -Allyl Amides to Difluoromethylated β-Amino Alcohols by Photoredox Catalysis.

An elegant tandem reaction process for transferring -allyl amide into CFH-β-amino alcohol is described. This approach proceeded smoothly under visible light irradiation in the presence of a 3 mol % Ir complex, exhibiting a broad substrate scope and functional group tolerance, and a variety of CFH-β-amino alcohols were readily accessed in good to excellent yields under mild conditions. The reliable mechanistic studies revealed that sequential difluoromethyl radical addition/carbocation trap/rearrangement is involved.