Radical C−H Trifluoromethoxylation of (Hetero)arenes with Bis(trifluoromethyl)peroxide

• Published in: Chemistry : a European journal Vol. 27; no. 45; pp. 11554 - 11558
• Main Authors: Dix, Stefan, Golz, Paul, Schmid, Jonas R., Riedel, Sebastian, Hopkinson, Matthew N.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 11-08-2021; John Wiley and Sons Inc
• Subjects: (hetero)arenes; Aromatic compounds; Atom economy; Catalysis; Chemistry; Communication; Communications; fluorine; Indicators and Reagents; Light; Peroxide; Peroxides; photocatalysis; Pyridines; Reagents; TEMPO; trifluoromethoxylation; TEMPO; (hetero)arenes; trifluoromethoxylation; photocatalysis; fluorine
• ISSN: 0947-6539; 1521-3765; 1521-3765
• DOI: 10.1002/chem.202101621

Trifluoromethoxylated (hetero)arenes are of great interest for several disciplines, especially in agro‐ and medicinal chemistry. Radical C−H trifluoromethoxylation of (hetero)arenes represents an attractive approach to prepare such compounds, but the high cost and low atom economy of existing .OCF3 radical sources make them unsuitable for the large‐scale synthesis of trifluoromethoxylated building blocks. Herein, we introduce bis(trifluoromethyl)peroxide (BTMP, CF3OOCF3) as a practical and efficient trifluoromethoxylating reagent that is easily accessible from inexpensive bulk chemicals. Using either visible light photoredox or TEMPO catalysis, trifluoromethoxylated arenes could be prepared in good yields under mild conditions directly from unactivated aromatics. Moreover, TEMPO catalysis allowed for the one‐step synthesis of valuable pyridine derivatives, which have been previously prepared via multi‐step approaches.
Bis(trifluoromethyl)peroxide (BTMP) is introduced as a new reagent for the C−H trifluoromethoxylation of arenes and heteroarenes. Readily accessed from inexpensive bulk chemicals, BTMP serves as a practical source of •OCF3 radicals upon activation through either visible light photoredox or TEMPO catalysis. Both methods deliver valuable fluorine‐containing building blocks in a single step from (hetero)aromatic feedstocks.