Synthesis and Derivatization of 1,1‐[18F]Difluorinated Alkenes

A general method for the synthesis of 1,1‐[¹⁸F]difluorinated alkenes from [¹⁸F]fluoride is reported. This transformation is highly regioselective giving the desired ¹⁸F‐fluoroalkenes with radiochemical purities of up to 77 % within 20 minutes and a molar activity (A_m) of 1 GBq μmol^?1. The transformations are operationally simple to perform and were readily translated onto a commercial automated synthesis unit. The resultant 1,1‐[¹⁸F]difluorinated alkene motif is prevalent in numerous drug molecules, and this is the first general method to synthesize this motif with fluorine‐18. ¹⁸F‐fluorinated alkenes are excellent building blocks and participate in a number of post‐labeling transformations to access a range of ¹⁸F‐perfluorinated functional groups that have never before been radiolabeled with non‐carrier‐added [¹⁸F]fluoride. This method considerably expands the range of ¹⁸F‐motifs accessible to radiochemists.