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We show that the incorporation of a biotinylated Co(TAML) cofactor within streptavidin enables asymmetric radical-type oxygen atom transfer catalysis with improved activity and enantioselectivity. [ABSTRACT FROM AUTHOR]

Enantioselective C-H amidation offers attractive means to assemble C-N bonds to synthesize high-added value, nitrogen-containing molecules. In recent decades, complementary enzymatic and homogeneous-catalytic strategies for C-H amidation have been reported. Herein, we report on an artificial metalloenzyme (ArM) resulting from anchoring a biotinylated Ir-complex within streptavidin (Sav). The resulting ArM catalyzes the enantioselective amidation of unactivated C( sp 3 )-H bonds. Chemogenetic optimization of the Ir cofactor and Sav led to significant improvement in both the activity and enantioselectivity. Up to >700 TON and 92% ee for the amidation of unactivated C( sp 3 )-H bonds was achieved. The single crystal X-ray analysis of the artificial nitrene insertase (ANIase) combined with quantum mechanics-molecular mechanics (QM-MM) calculations sheds light on critical second coordination sphere contacts leading to improved catalytic performance.

Iron-sulfur clusters have been reported to catalyze various redox transformations, including the multielectron reduction of CO 2 to hydrocarbons. Herein, we report the design and assembly of an artificial [Fe 4 S 4 ]-containing Fischer-Tropschase relying on the biotin-streptavidin technology. For this purpose, we synthesized a bis-biotinylated [Fe 4 S 4 ] cofactor with marked aqueous stability and incorporated it in streptavidin. The effect of the second coordination sphere provided by the protein environment was scrutinized by cyclic voltammetry, highlighting the accessibility of the doubly reduced [Fe 4 S 4 ] cluster. The Fischer-Tropschase activity was improved by chemo-genetic means for the reduction of CO 2 to hydrocarbons with up to 14 turnovers.