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Updated: Oct 3, 2025

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Organocatalytic Enantioselective Sulfa-Michael Additions to α,β-Unsaturated Diazoketones
Patricia B Momo1, Eduardo F Mizobuchi1, Radell Echemendía1
1Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, São Paulo CEP 13560-970, Brazil.
Abstract:
Enantioselective sulfa-Michael additions to α,β unsaturated diazocarbonyl compounds have been developed. Quinine-derived squaramide was found to be the best catalyst to promote C-S bond formation in a highly stereoselective fashion for alkyl and aryl thiols. The easy-to-follow protocol allowed the preparation of 22 examples in enantiomeric ratios up to 97:3 and reaction yields up to 94%. The mechanism and origins of enantioselectivity were determined through density functional theory (DFT) calculations.
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