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Updated: Nov 29, 2025

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
α-Functionalization of Ketones via a Nitrogen Directed Oxidative Umpolung
Gabriel M Kiefl1, Tanja Gulder1,2
1Department of Chemistry, Technical University Munich, Lichtenbergstrasse 4, 85748 Garching, Germany.
Abstract:
Reversing the polarity in molecules is a versatile tool for expanding the boundaries of structural space. Despite a manifold of different umpolung methods available today, overcoming the inherent reactivity still remains a constant challenge in organic chemistry. The oxidative α-functionalization of ketones by external nucleophiles constitute such an example. Herein, we present a hypervalent F-iodane mediated umpolung of pyridyl ketones triggered by Lewis base/Lewis acid noncovalent interactions. A wide variety of external nucleophiles are introduced with high regioselectivity applying this substrate-directing concept.
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