Electrochemically triggered transformations of alcohols
Time: Fri 2026-11-20 10.00
Location: Kollegiesalen, Brinellvägen 8, Stockholm
Language: English
Subject area: Chemistry
Doctoral student: Malin Lill , Organisk kemi
Opponent: Richard C D Brown, University of Southampton
Supervisor: Universitetslektor Helena Lundberg, Organisk kemi
QC 2026-10-21
Abstract
This thesis discusses electrosynthetic approaches for cleaving and functionalising C–OH bonds in alcohols. This compound class is highly abundant and diverse but remains underrepresented as a source of alkyl synthons in synthetic organic chemistry. Using electrosynthesis, electrons are considered traceless ‘reagents’ for transforming alcohol building blocks into other products, offering a complementary synthetic route to traditional strategies that can lead to benefits from a sustainability perspective.
The first part of the thesis focuses on direct electroreductive C–OH cleavages, where a two-electron reduction generates a carbanionic intermediate. The carbanion is further trapped to forge new C–H, C–C or C–Si bonds, with selectivity relying on the reduction potential of the reacting partners and the thermodynamic/kinetic driving forces for the cross-coupling (Papers I-II). Additionally, the oxidative counter reaction of such electroreductive transformations is discussed. Traditionally, oxidation of sacrificial metals is applied as counter reaction for electroreductive transformations, liberating metal cations into the reaction mixture. In this thesis, a complementary approach relying on borohydride oxidation is disclosed and assessed for five electroreductive methods (Paper III).
The second part of the thesis addresses different reactivity patterns for C–OH cleavage or formation using alcohols and thioethers. The mechanism of thioether oxidation is well-established, proceeding via a radical cation speciesthat can either react with nucleophile or fragment, depending on its backbone.In this thesis, the former pathway is explored in Paper IV, in which a method for the formation and trapping of the thioether radical cation with an alcohol is discussed and harnessed for deoxygenative chlorination. The fragmentation pathway is explored in Paper V, leveraging thioethers as alkyl donors via the electrooxidative generated carbocation for use in etherification, esterification and alkylation routes with different O- and N-nucleophiles.