To Study the Effect of Fluoroalkylation of Alkenes

Abstract

Difluoroalkylated chemicals are useful in materials science, pharmacology, and agrochemistry. Nevertheless, there are very few effective ways to create the alkylCF2-alkyl bond, and it is still difficult to introduce a difluoromethylene (CF₂) group into an aliphatic chain at the appropriate location. Here, we describe a novel instance of alkylzirconocene-promoted difluoroalkylation of alkyl- and silyl-alkenes using a range of unactivated difluoroalkyl iodides and bromides when exposed to visible light without the need of a catalyst. In organic synthesis, the resultant difluoroalkylated molecules can be used as flexible synthons. The reaction offers a general way to controllably access fluorinated compounds and can also be used with activated difluoroalkyl, trifluoromethyl, perfluoroalkyl, monofluoroalkyl, and nonfluorinated alkyl halides. According to preliminary mechanistic studies, the process involves a single electron transfer (SET) route initiated by a Zr(III) species, which is produced when alkylzirconocene is photolyzed with blue light.