Photocatalytic fluoroalkylation reactions of organic compounds

Abstract

Photocatalytic methods for fluoroalkyl-radical generation provide more convenient alternatives to the classical perfluoroalkyl-radical (R_f) production through chemical initiators, such as azo or peroxide compounds or the employment of transition metals through a thermal electron transfer (ET) initiation process. The mild photocatalytic reaction conditions tolerate a variety of functional groups and, thus, are handy to the late-stage modification of bioactive molecules. Transition metal-photocatalytic reactions for R_f radical generation profit from the redox properties of coordinatively saturated Ru or Ir organocomplexes to act as both electron donor and reductive species, thus allowing for the utilization of electron accepting and donating fluoroalkylating agents for R_f radical production. On the other hand, laboratory-available and inexpensive photoorgano catalysts (POC), in the absence of transition metals, can also act as electron exchange species upon excitation, resulting in ET reactions that produce R_f radicals. In this work, a critical account of transition metal and transition metal-free R_f radical production will be described with photoorgano catalysts, studying classical examples and the most recent investigations in the field.