Biocatalytic Regio‐ and Enantiocomplementary Synthesis of Chiral Aryloxazolidinones

Abstract We described the protein engineering of the halohydrin dehalogenase HheG to enhance its R enantioselectivity for the synthesis of chiral 4‐aryloxazolidinones via α‐regioselective ring‐opening of aryl epoxides with cyanate. Additionally, we achieved the inversion of its regioselectivity and enantioselectivity, resulting in a HheG variant tailored for the synthesis of chiral 5‐aryloxazolidinones via β‐regioselective and S ‐enantioselective ring‐opening of aryl epoxides with cyanate. Leveraging these engineered mutants, we developed a biocatalytic platform capable of synthesis of both chiral 4‐aryloxazolidinones (up to 47% yield, 98% ee , and 99% regioselectivity) and chiral 5‐aryloxazolidinones (up to 46% yield, >99% ee , and 98% regioselectivity). Furthermore, a collaborative approach utilizing two regio‐ and enantioselective HheG mutants has been demonstrated to enable the simultaneous synthesis of chiral 4‐aryloxazolidinones and chiral 5‐aryloxazolidinones.