The selective functionalization of unactivated C-H bonds remains one of the greatest challenges in catalysis. Inspiration can be taken from nature, where selective enzymatic C-H halogenation plays a critical role in numerous biochemical processes. In addition to their incorporation in natural products and related biological and medicinal applications, halogenated compounds find a wide variety of uses in therapeutic drugs and agrochemicals. The enzymes that carry out C-H activation are typically a-ketoglutarate (aKG)-dependent enzymes that operate under ambient conditions with strong regioselectivity and stereoselectivity resulting in the catalysis of a wide variety of reactions , including halogenation. For non-heme iron halogenases in particular , e.g., SyrB2 , CytC3 , WelO5 , and BesD, the active sites are similar to other non-heme iron enzymes with only one major change. In comparison to more well understood non-heme iron hydroxylases, the halogenases have a halide coordinating the metal center, i.e., native chloride or non-native bromide. This halide is bound in place of a carboxylate of the 2-His-1-carboxylate facial triad of the hydroxylases because in the halogenases there is no carboxylate-bearing aspartate or glutamate residue present and instead a non-coordinating alanine residue is typically present to create a hydrophobic pocket for halide binding. Despite this understanding of halogenases, it is extremely hard to develop selective processes for C-H halogenation using synthetic methods due to the inertness of C-H bonds and their high bond dissociation energy.