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Updated: May 21, 2025

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Enantioselective Organocatalytic Addition of 1,3-Dicarbonyl Compounds to β-Arylvinyl Triflones
Michał Kopyt1,2, Jan Dudziński1, Michał Barbasiewicz1
1University of Warsaw, Faculty of Chemistry, Pasteura 1, 02-093 Warsaw, Poland.
Abstract:
The sulfonyl group is able to polarize adjacent C=C bonds, but strength of the effect considerably varies with sulfonyl substituents (SO2X). In this report, we present asymmetric organocatalyzed conjugate addition of 1,3-dicarbonyl compounds to β-arylvinyl triflones (ArCH=CHSO2CF3). The reaction runs under mild conditions with 5 mol % of tertiary amino-thiourea to afford Michael-type adducts in high yields and enantioselectivities. Comparative experiments reveal that electron-withdrawing properties increase in the series SO2F ≪ SO2CF3 < SO2C4F9, with the latter approaching strength of the nitro group.
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