In 2023, through the cooperative interactions between the biocatalyst and the small-molecule photosensitizer, our group reported the first use of pyridoxal 5'-phosphate (PLP)-dependent enzymes to catalyze asymmetric intermolecular radical C-C couplings which were not previously known in either organic chemistry or biochemistry. In this process, the key reactive radical intermediate forms photocatalytically outside the enzyme active site and then travel into the active site, likely guided by hydrophobic interactions with the enzyme pocket, for productive bond formation with an enzymatic intermediate. By separating radical generation from enzymatic substrate activation, this new mechanism holds the potential to be generalized to diverse enzyme families, including those lacking a redoxactive cofactor. Furthermore, external radical generation from a discrete photoredox cycle enables biocatalytic radical transformations to be carried out in an intermolecular sense, which remains a currently unmet challenge for several biocatalytic activation modes involving radical initiation within the active site. Cognizant of the tremendous potential of external radical generation via cooperative catalysis for developing new biocatalytic radical reactions, we sought to generalize this strategy to other enzyme families. Due to our ongoing focus on the engineering of heme 8 and nonheme 9c Fe enzymes for enantioselective radical processes, we questioned whether cooperative photometallobiocatalysis could be achieved with nonheme Fe enzymes to allow for asymmetric carbon-heteroatom bond formation via a radical mechanism. Inspired by pioneering studies illuminating the reactivity of nonheme Fe(III)-X (X = halogen, 9b,9c,15 N3, and NCS 17 ) with both Fe enzymes and small-molecule model Fe complexes, we posited that the externally formed free radical intermediate could be intercepted by an enzymatic Fe(III)-X species (X = N3, NCS and NCO), thereby providing a unifying strategy for catalytic asymmetric azidation, thiocyanation and isocyanation of open-shell intermediates. Despite extensive recent studies on transition-metal catalyzed azidation 20 and related radical functionalization reactions 21 in the arena of synthetic organic chemistry, to date, catalytic asymmetric radical thiocyanation and isocyanation 23 has remained unknown with chiral small-molecule transition-metal catalysts. Thus, the development of nonheme Fe enzyme-catalyzed asymmetric radical rebound reactions will provide a new platform to address this challenge.