Visible light-catalyzed fluoroalkylation reactions of free aniline derivatives.

ABSTRACT

The electron-rich nature of aminoaromatic compounds and the electrophilic character of fluoroalkyl RF radicals allow for a special match in substitution reactions. We herein present visible light photocatalyzed fluoroalkylation reactions of aniline derivatives, with a study of the reaction mechanisms. The examples evaluated make use of different photocatalysts, such as polypyridyl complexes of Ir or Ru transition metals, organic dyes such as Rose Bengal, phthalocyanine-metal organocatalysts, or visible-light activated complexes. Different visible light sources that span from the blue region of the electromagnetic spectrum to low power red light irradiation sources deliver the excited photocatalysts that ensue into the production of fluoroalkyl RF radicals. In turn, many sources of RF radicals can be employed, such as fluoroalkyl halides, Togni's reagents, Umemoto's reagent, etc. All these protocol variants demonstrate the expansion of the methodology and the versatility of photocatalytic techniques applied to a special family of organic compounds such as aminoaromatic substrates, which has been studied by different groups. Contributions from our own laboratory will be given.