1498289-01-2Relevant articles and documents
Optimizing the structure of 4-dialkylamino-α,α-diarylprolinol ethers as catalysts for the enantioselective cyclopropanation of α,β-unsaturated aldehydes in water
Martinez, Jose I.,Reyes, Efraim,Uria, Uxue,Carrillo, Luisa,Vicario, Jose L.
, p. 2240 - 2247 (2013)
We optimized the structure of a new family of chiral diarylprolinol-type organocatalysts with improved performances in conjugate addition reactions performed in water and proceeding under the iminium activation manifold. The principles behind the catalyst
Biocatalytic Asymmetric Cyclopropanations via Enzyme-Bound Iminium Ion Intermediates
Kunzendorf, Andreas,Poelarends, Gerrit J.,Saifuddin, Mohammad,Saravanan, Thangavelu,Xu, Guangcai
supporting information, p. 24059 - 24063 (2021/10/07)
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 2-chloromalonate 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.
