Radical Functionalisation of Alkenes

A main objective in organic chemistry is the concise formation of C–C bonds, and the reaction between a carbon centred radical and an alkene moiety has emerged as a reliable method to this end. In this Thesis, we describe the reaction of carbon-centred radicals with alkenes to form a new C–C bond, a...

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Bibliographic Details
Main Author: Himmel, Leonard
Format: Thesis (University of Nottingham only)
Language:English
Published: 2023
Subjects:
Online Access:https://eprints.nottingham.ac.uk/74389/
Description
Summary:A main objective in organic chemistry is the concise formation of C–C bonds, and the reaction between a carbon centred radical and an alkene moiety has emerged as a reliable method to this end. In this Thesis, we describe the reaction of carbon-centred radicals with alkenes to form a new C–C bond, and different methods were explored to convert the resulting radical intermediate into potentially valuable products or building blocks for further operations. In Chapter 2, the stepwise formal addition of simple alcohols to styrenes via an oxyalkylation intermediate is reported. The required alkyl radicals originate from N- hydroxyphthalimide esters and are generated using photoredox catalysis. The oxyalkylation intermediate fragments under mild Brønsted acidic conditions via a 1,5-hydride transfer process to give the target product. Mechanistic investigations were conducted to gain better understanding of the key 1,5-hydride transfer step. Fluorinated compounds have sparked great interest in organic chemistry due to their unique biological properties. In Chapter 3, we report several possibilities to synthesise such products through the carbofunctionalisation of alkenes via a radical polar crossover reaction. The reaction of α-trifluoromethyl styrenes with alkyl radicals in the presence of O- or N-based nucleophiles yields quaternary trifluoromethyl-functionalised products. Finally, we describe a carboarylation of unactivated alkenes via a radical Truce-Smiles rearrangement on β-arylsulfate alkenes in Chapter 4. Herein, the reaction commenced with the generation of a fluorinated carbon-centred radical, followed by its interaction with an unactivated alkene. The migration ability of various aryl groups was analysed.