Biocatalytic Asymmetric Cyclopropanations via Enzyme‐bound Iminium Ion Intermediates

Andreas Kunzendorf, Guangcai Xu, Mohammad Saifuddin, Thangavelu Saravanan, Gerrit J. Poelarends*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

Cyclopropane rings are an important structural motif frequently found in many natural products and pharmaceuticals. Commonly, biocatalytic methodologies for the asymmetric synthesis of cyclopropanes rely on repurposed or artificial heme enzymes. Here, we engineered an unusual cofactor-independent cyclopropanation enzyme based on a promiscuous tautomerase for the enantioselective synthesis of various cyclopropanes via the nucleophilic addition of diethyl 2chloromalonate to α,β-unsaturated aldehydes. The engineered enzyme promotes formation of the two new carbon-carbon bonds with excellent stereocontrol over both stereocenters, affording the desired cyclopropanes with high diastereo- and enantiopurity (d.r. up to 25:1; e.r. up to 99:1). Our results highlight the usefulness of promiscuous enzymes for expanding the biocatalytic repertoire for non-natural reactions.
Original languageEnglish
Pages (from-to)24059-24063
JournalAngewandte Chemie International Edition
Volume2
Early online date7-Sep-2021
DOIs
Publication statusPublished - 2-Nov-2021

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