Iron-mediated C-H coupling of arylsulfides and simple terminal alkenes

Abstract

The use of directing groups in C-H functionalisation reactions provides a means to control the regioselectivity of such processes. Previous work in the Procter group reported the sulfoxide-directed metal-free C-H alkylation of arenes with organosilane nucleophiles. Attempts to expand this work by carrying out a similar process directly from the sulfide oxidation level, utilising an Fe(III) oxidant, a diarylsulfide and an alkene are discussed herein.During these investigations, it was discovered that the use of simple, unfunctionalised olefins selectively gave linear products of formal chloroarylation, which represents a novel transformation. Following optimisation studies, the reaction proceeded in good to moderate yield under exceptionally mild conditions with a range of alkene and sulfide coupling partners, although sulfides do require a particular oxygenation pattern in the aryl ring undergoing coupling. Based on various experimental observations, a single electron oxidation process is believed to be responsible for the desired reactivity.A number of manipulations of the chlorinated products are demonstrated, including their use in an expedient synthesis of important dihydrobenzofuran motifs. The original sulfur directing-group has also been used as a handle for further elaboration of these interesting structures.

Date of Award	1 Aug 2016
Original language	English
Awarding Institution	The University of Manchester
Supervisor	David Procter (Supervisor) & Michael Greaney (Supervisor)