Enantioselective Hydroxylation of Benzylic C(sp(3))–H Bonds by an Artificial Iron Hydroxylase Based on the Biotin–Streptavidin Technology

[Image: see text] The selective hydroxylation of C–H bonds is of great interest to the synthetic community. Both homogeneous catalysts and enzymes offer complementary means to tackle this challenge. Herein, we show that biotinylated Fe(TAML)-complexes (TAML = Tetra Amido Macrocyclic Ligand) can be used as cofactors for incorporation into streptavidin to assemble artificial hydroxylases. Chemo-genetic optimization of both cofactor and streptavidin allowed optimizing the performance of the hydroxylase. Using H(2)O(2) as oxidant, up to ∼300 turnovers for the oxidation of benzylic C–H bonds were obtained. Upgrading the ee was achieved by kinetic resolution of the resulting benzylic alcohol to afford up to >98% ee for (R)-tetralol. X-ray analysis of artificial hydroxylases highlights critical details of the second coordination sphere around the Fe(TAML) cofactor.