Aliphatic C-H azidation by Mn based mimics of -ketoglutarate dependent enzymes

alpha-Ketoglutarate dependent nonheme halogenases catalyze regioselective functionalization of aliphatic C-H bonds via H abstraction by the ferryl site of the [X-FeIV=O] intermediate, followed by radical rebound to an adjacent halogen ligand X at the same Fe center. Herein we report biomimetic nonheme Mn complexes, possessing two labile cis-alpha coordination sites and capable of catalyzing the enantioselective azidation of C(sp3)-H groups. Proper ligand environment of the active sites imposes steric constraints on HO-Mn rebound, thus accounting for preferential C-radical rebound to the adjacent N3-Mn ligand. Such mechanism of selectivity control is analogous to that operating in the prototypical alpha-ketoglutarate-dependent nonheme iron halogenases.