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Updated: May 23, 2025
A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Diastereoselective Umpolung cyclisation of ketones promoted by hypervalent iodine
Giulia Iannelli1, Philipp Spieß1, Ricardo Meyrelles1,2
1Institute of Organic Chemistry, University of Vienna Währinger Straße 38 1090 Vienna Austria nuno.maulide@univie.ac.at.
Abstract:
Umpolung reactivity facilitated by hypervalent iodine has emerged as an appealing method for the efficient α-functionalization of ketones. However, skeletal reorganisation or migration reactions remain comparatively underexplored, primarily due to the challenging taming of transient carbocationic intermediates. In this study, we introduce a method for the functionalisation of ketones, employing a 6-endo-trig cyclisation initiated by Umpolung of silyl enol ethers, resulting in the diastereoselective formation of cis-substituted cyclohexanes. Additional investigations, both experimental and computational, give insight into the mechanistic intricacies of this process, and shed light on an unconventional iodine(iii)-reactivation mechanism.
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