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Updated: Jan 24, 2026

Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks MOFs
Published on: January 17, 2020
Enantioselective Protonation of Enol Esters with Bifunctional Phosphonium/Thiourea Catalysts
Eiji Yamamoto1, Kodai Wakafuji1, Yusuke Mori1
1Department of Chemistry, Graduate School of Science , Kyushu University , Fukuoka , 819-0395 , Japan.
Abstract:
Bifunctional phosphonium/thioureas derived from tert-leucine behaved as highly selective catalysts for enantioselective protonation of enol esters, providing α-chiral ketones in yields of up to 99% with high enantioselectivities (up to 98.5:1.5 er). Control experiments clarified that a bulky tert-butyl group and phosphonium and thiourea moieties were necessary to achieve such high stereoselectivity. In addition, mechanistic investigations indicated the catalyst was converted to the corresponding betaine species, which served as a monomolecular catalyst.
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