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Updated: Aug 8, 2026

Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade
Published on: August 14, 2019
Silver-catalyzed [2 + 2] cycloadditions of siloxy alkynes
Randy F Sweis1, Michael P Schramm, Sergey A Kozmin
1University of Chicago, Department of Chemistry, 5735 South Ellis Ave, Chicago, Illinois 60637, USA.
Abstract:
We have described the first [2 + 2] cycloadditions of siloxy alkynes with a range of unsaturated carbonyl compounds. The reactions are efficiently promoted by substoichiometric amount of silver trifluoromethanesulfonimide and display excellent regio- and diastereoselectivity combined with a broad substrate scope. Our studies have established unambiguously the stepwise mechanism of this process and provided evidence for a novel role of silver in the catalytic cycle of the reaction, which involves silver-based complexation and activation of siloxy alkyne toward the subsequent 1,4-addition.
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