The substrate scope was explored for HDF of a range of other fluoroarenes and heterocycles (Scheme 2, HDF products 2-11). In addition, it was possible to determine conditions for the selective reductive coupling of 1 to 3 and to explore preliminary aminodefluorination reactions (products 12 and 13) to tri-and difluoropyridine isomers. This explains the selectivity of the HDF conditions in Table , entry 6, as a second HDF at the less activated ortho-position of the pyridine is substantially slower than the initial reaction at the para-position of 1. The presence of other tri-and difluoropyridines suggests that the rate of HDF at the ortho-and meta-positions is more similar than the rate of HDF at the paraposition. Reducing the degree of fluorination of the substrate, but maintaining a C-F bond at the most reactive para-position also allowed HDF and formation of 5 (79% yield), but the reaction was relatively slow and a small amount of unreacted 2,4,6-trifluoropyridine (5%) was present, along with some 2,4difluoropyridine (14%), which results from ortho-HDF, after 6 days. It is clear that more electron-poor heteroaromatics lead to faster reactions, which is consistent with the mechanistic proposal (see below).