Indium-Catalyzed C-F Bond Transformation through Oxymetalation/β-Fluorine Elimination to Access Fluorinated Isocoumarins

Fluorinated heterocycles have attracted much attention in the pharmaceutical and agrochemical industries. Many strategies have already been developed to achieve the synthesis of fluorinated heterocycles. Formidable challenges remain, however, in the synthesis of fluorinated isocoumarin derivatives that are among the most alluring structural motifs. Herein, the indium-catalyzed C-F bond transformation of 2-(2,2-difluorovinyl) benzoates is reported, which are readily accessible compounds, to give a diverse array of fluorinated isocoumarins. The present reaction proceeds smoothly using inexpensive reagents: a catalytic amount of indium salt in the presence of zinc salt. A theoretical calculation of potential energy profiles showed that the reaction consists of oxymetalation with the elimination of alkyl halide and the beta-fluorine elimination.

Automated summary

Fluorinated heterocycles have been a focus in the pharmaceutical and agrochemical industries, with various strategies developed for their synthesis. Challenges still remain in the synthesis of fluorinated isocoumarin derivatives. A recent study reported the successful synthesis of diverse fluorinated isocoumarins using indium-catalyzed C-F bond transformation, with the reaction proceeding smoothly with inexpensive reagents.