P450-catalyzed enantiodivergent kinetic oxidation to access chiral haloalcohols

Chiral recognition constitutes the central element of asymmetric catalysis. The control over stereoselectivity becomes more precise with the greater diversity of substituent groups introduced. Distinguishing between high similarity substituents has been a challenge in asymmetric catalysis. Herein, we report an enzymatic approach enabling kinetically enantioselective hydroxylation of (2-chloropropyl)benzene derivatives with excellent stereoselectivity, though the difference of substituent radius between methyl and chloro substituents is 0.07 Å. The cytochrome P450 enzyme P450PL2 is engineered through multiple mutagenesis strategies to enhance both its substrate selectivity and stereoselectivity, thereby enabling the enantiodivergent synthesis of haloalcohols with two stereocenters. Molecular dynamic simulations and DFT calculations infer that the engineered P450PL2 exhibits steric discrimination capability, which enables host-guest interaction with a chiral center bearing methyl and chloro substituents. The biocatalytic system provides efficient access to the 2-chloro-benzyl alcohol derivatives with up to 99:1 enantiomeric ratio and >99:1 diastereomeric ratio. Differentiation between highly similar substituents is a challenge in asymmetric catalysis. Here, the authors report an enzymatic approach enabling kinetically enantioselective hydroxylation of (2- chloropropyl)benzene derivatives using engineered P450PL2 to obtain the 2-chloro-benzyl alcohol derivatives with up to 99:1 enantiomeric ratio and >99:1 diastereomeric ratio.