Enzymatic Lactone-Carbene C‒H Insertion to Build Contiguous Chiral Centers

Abstract

We report a biocatalytic platform of engineered cytochrome P411 enzymes (P450s with axial serine ligation) to carry out efficient lactone-carbene insertion into primary and secondary α-amino C–H bonds. Directed evolution of a P450 variant, P411-C10, yielded a lineage of enzyme variants capable of forming chiral lactone derivatives with high catalytic efficiency (up to 4000 TTN) and in a stereodivergent manner. For carbene insertion into secondary C–H bonds, a single mutation was discovered to invert the two contiguous chiral centers and lead to the opposite enantiomers of the same major diastereomers. This work demonstrates the utility of engineered enzymes for asymmetric catalysis and highlights the remarkable tunability of these genetically encoded biocatalysts for accessing the desired selectivities.