Copper Complexes with Protein‐Based N‐Donor Ligands as cis‐Selective Nascent Cyclopropanases.

In this study, we aimed to develop protein‐based metal ligands to catalyze <italic>cis</italic>‐selective cyclopropanation using the TM1459 cupin protein superfamily. Copper complexes with TM1459 mutants containing the 3‐His metal‐binding site exhibited excellent diastereoselectivity in cyclopropanation reactions with styrene and ethyl diazoacetate. Further mutations in the secondary coordination sphere increased the <italic>cis</italic>‐preference with <italic>t</italic>‐butyl diazoacetate as the substrate with up to 80 : 20 (<italic>cis</italic>:<italic>trans</italic> ratio) and high enantioselectivity (90 % <italic>ee</italic>). [ABSTRACT FROM AUTHOR]