Novel approaches for Ru-promoted C-H arylation methods

• Main Author: Simoneti, Marco
• Published: Queen Mary, University of London 2016
• Subjects: Chemistry
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.765820

The development of new procedures for the production of biologically and industrially relevant compounds still remains a big challenge in chemistry. The biaryl motif is ubiquitous among a wide range of compounds of industrial importance. For example, the biaryl skeleton is found in molecular switches and motors, agrochemicals or medicines such as antifungal, anticancer, antibiotics, anti-inflammatory treatments. These properties make the biaryl functionality a highly desirable synthetic target, for both commercial and research purposes. In this context, C-H arylation has been acknowledged as a useful alternative to traditional cross-couplings, replacing the organometallic coupling partner by a non-prefunctionalised substrate in the reaction with a haloarene. Approaches for the development of Ru-catalysed C-H arylation methodologies are presented herein. The introduction provides a general overview about different strategies employed in metalcatalysed direct C-H arylation methods. The rational behind selectivity and reactivity are also thoroughly discussed. The second chapter describes studies on the C-H activation of perfluorinated arenes by Ru(II)-species. The synthesis of unprecedented aryl rutyhenium complexes and mechanistic considerations on the metalation of the arene are presented. In the last part of the second chapter the development of a bis-cationic rutehium(II) complex able to catalyse direct C-H arylation of electron-poor arenes with bromoarenes in the absence of any directing group is described. A complete mechanistic analysis, along with the scope of the methodology, is therefore given.