Transition-metal-free trifluoromethylative difunctionalization of olefins and alkynes: approaches and challenges ahead
Strategies for the introduction of the trifluoromethyl group in organic molecules have been extensively explored in the past. Trifluoromethylative difunctionalization of carbon–carbon multiple bonds opens a new horizon for the synthesis of complex molecules by the simultaneous formation of C–CF3 and C–C/C–heteroatom bonds in a single chemical operation. Transition-metal-free strategies for such transformations are gaining importance because of increasing demand for the development of environmentally friendly methodologies and also will be of interest to the chemists involved in pharmaceutical and agrochemical research to conduct more research in this field and contribute to the growth of fluorine chemistry. In this review, we summarize the recent developments in the transition-metal-free strategies for trifluoromethylation based difunctionalization reactions of alkenes and alkynes using an organocatalyst or oxidant, or even without any additional additive/reagent.