Access to Trifluoromethylketones from Alkyl Bromides and Trifluoroacetic Anhydride by Photocatalysis

Aliphatic trifluoromethyl ketones are a type of unique fluorine-containing subunit which play a significant role in altering the physical and biological properties of molecules. Catalytic methods to provide direct access to aliphatic trifluoromethyl ketones are highly desirable yet remain underdeveloped, partially owing to the high reactivity and instability of trifluoroacetyl radical. Herein, we report a photocatalytic synthesis of trifluoromethyl ketones from alkyl bromides with trifluoroacetic anhydride. The reaction features dual visible-light and halogen-atom-transfer catalysis, followed by an enabling radical-radical cross-coupling of an alkyl radical with a stabilized trifluoromethyl radical. The reaction provides straightforward access to aliphatic trifluoromethyl ketones from readily available and cost-effective alkyl halides and trifluoroacetic anhydride (TFAA).

Automated summary

In this study, a photocatalytic synthesis of trifluoromethyl ketones from alkyl bromides and trifluoroacetic anhydride was reported. The reaction involved dual visible-light and halogen atom-transfer catalysis, followed by a radical-radical cross-coupling between an alkyl radical and a stabilized trifluoromethyl radical. This method provides a straightforward access to aliphatic trifluoromethyl ketones from readily available and cost-effective starting materials.