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Updated: May 16, 2026

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes
Published on: November 21, 2017
Photochemical and thermal ring-contraction of cyclic hydroxamic acid derivatives
Simon Pichette1, Samuel Aubert-Nicol, Jean Lessard
1Département de Chimie, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1K 2R1.
Abstract:
Cyclic hydroxamic acids can undergo a thermal ring contraction after an in situ triflation. High yields of ring-contraction products are obtained with DBU when the migrating carbon is a methylene, while best results are obtained with Et(3)N for the migration of quaternary carbons. In some cases, the regiochemical outcome of the reaction can be controlled by changing the base. This novel thermal rearrangement complements a similar but photochemical rearrangement of N-mesyloxylactams.
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