From the top down; access to complex multifluorinated arenes via multiple photocatalytic C–F substitutions.

Novel N-(Cbz-aminoacyl)thiosemicarbazides 3a-c were cyclized by treatment with sulfuric acid to give 1,3,4-thiadiazoles 4a-c. Compounds 4a-c reacted with N-(Cbz-aminoacyl)- and -dipeptidoylbenzotriazoles to afford chirally pure 1,3,4-thiadiazol-2-yl-substituted amino acids 6a-c and dipeptides 7a-c.

The photocatalytic reductive alkylation of pentafluorides such as (I) and (IV) with alkenes in the presence of 1.2 equiv.