Enantioselective Hydroxylation of Benzylic C(sp3)-H Bonds by an Artificial Iron Hydroxylase Based on the Biotin-Streptavidin Technology.
Serrano-Plana, J., Rumo, C., Rebelein, J.G., Peterson, R.L., Barnet, M., Ward, T.R.(2020) J Am Chem Soc 142: 10617-10623
- PubMed: 32450689 
- DOI: https://doi.org/10.1021/jacs.0c02788
- Primary Citation of Related Structures:  
6Y25, 6Y2M, 6Y2T, 6Y33, 6Y34, 6Y3Q - PubMed Abstract: 
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.
Organizational Affiliation: 
Department of Chemistry, University of Basel, BPR1096, Mattenstrasse 24a, CH-4058 Basel, Switzerland.