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Updated: Aug 3, 2025

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Deconstructive Pyridylation of Unstrained Cyclic Amines through a One-Pot Umpolung Approach
Seonghyeok Hong1,2, Byeongseok Kweon1,2, Wooseok Lee1,2
1Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.
Abstract:
A one-pot umpolung method for the ring-opening pyridylation of unstrained cyclic amines was developed using N-amidopyridinium salts. This process involves the formation of electron donor-acceptor complexes between bromide and N-amidopyridinium salts, ultimately leading to the functionalization of pyridines. This protocol is compatible with a range of 5- or 6-membered cyclic amines and pyridines, thereby providing a powerful synthon for preparing C4-functionalized pyridines under visible-light conditions in the absence of an external photocatalyst.
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