Enantiodivergent α‑Amino C–H Fluoroalkylation Catalyzed by Engineered Cytochrome P450s

The introduction of fluoroalkyl groups
into organic compounds can
significantly alter pharmacological characteristics. One enabling
but underexplored approach for the installation of fluoroalkyl groups
is selective C­(sp3)–H functionalization
due to the ubiquity of C–H bonds in organic molecules. We have
engineered heme enzymes that can insert fluoroalkyl carbene intermediates
into α-amino C­(sp3)–H bonds
and enable enantiodivergent synthesis of fluoroalkyl-containing molecules.
Using directed evolution, we engineered cytochrome P450 enzymes to
catalyze this abiological reaction under mild conditions with total
turnovers (TTN) up to 4070 and enantiomeric excess (ee) up to 99%.
The iron-heme catalyst is fully genetically encoded and configurable
by directed evolution so that just a few mutations to the enzyme completely
inverted product enantioselectivity. These catalysts provide a powerful
method for synthesis of chiral organofluorine molecules that is currently
not possible with small-molecule catalysts.