title: Chemo- and diastereoselectivities in the electrochemical reduction of maleimides.
abstract: The electrochemical cathodic reduction of cyclic imides (maleimides) to succinimides can be achieved chemoselectively in the presence of alkene, alkyne, and benzyl groups. The efficiency of the system was demonstrated by using a 3D electrode in a continuous flow reactor. The reduction of 3,4-dimethylmaleimides to the corresponding succinimides proceeds with a 3:2 diastereomeric ratio, which is independent of the nitrogen substituent and electrode surface area. The stereoselectivity of the process was rationalized by using DFT calculations, involving an acid-catalyzed tautomerization of a half-enol occurring through a double hydrogen-transfer mechanism.
authors.affiliation: Department of Chemistry, Imperial College London, Exhibition Road, South Kensington, London SW7 2AZ (UK).
authors.forename: Kathryn
authors.initials: K
authors.lastname: Rix
authors.forename: Geoffrey H
authors.initials: GH
authors.lastname: Kelsall
authors.forename: Klaus
authors.initials: K
authors.lastname: Hellgardt
authors.forename: King Kuok Mimi
authors.initials: KK
authors.lastname: Hii
mesh_terms: D004563:Electrochemistry; D004566:Electrodes; D008301:Maleimides / Q000737:chemistry*; D010084:Oxidation-Reduction; D013237:Stereoisomerism; D013388:Succinimides / Q000737:chemistry*
chemical_list: D008301:Maleimides; D013388:Succinimides
keywords: chemoselectivity; diastereoselectivity; electrochemistry; reaction mechanisms; reduction