Atropisomerism is a property exhibited by molecules where rotation about one or more bonds is restricted. Along with biaryls, which are widely utilised in asymmetric catalysis, several other classes of compounds display atropisomerism. These molecules have applications in enantioselective synthesis, asymmetric catalysis and have been used to relay stereochemical information. There are, however, a number of challenges associated with their asymmetric synthesis (Chapter 1). This thesis describes research carried out on the synthesis and asymmetric synthesis of atropisomeric diaryl ethers. Chapter 2.1 explains how these ethers are synthesised in multi-gram quantities and to allow the incorporation of large ortho substituents. Having a number of diaryl ethers with suitable substitution patterns to achieve atropisomerism, Chapter 2.2 goes on to report two novel and complimentary biocatalytic approaches to the enantioselective synthesis of diaryl ethers by desymmetrisation. This chapter also describes a possible route towards the synthesis of a diaryl ether based ligand. Chapter 2.3 reports the lateral lithiation of meso diaryl ethers to yield diastereomeric atropisomers stereoselectively. Our attempts to use (-)-sparteine in lateral lithiations to desymmetrise a diaryl ether enantioselectively is also described. We go on to determine the configurational integrity of our organolithiums and the reaction pathway that exists in lithium substitution. Finally, the diastereoselective synthesis of both a diaryl ether (via a stereoselective reduction of a pro-chiral ketone) and a diaryl sulfide (via an addition reaction) is described in chapter 2.4. This chapter also reports the conformational behaviour of a diaryl amide in solution.

Polyarene dendrimers with rigid aromatic regions are of interest due to their shape persistent nature. A novel series of G1 dendrimers containing a substituted 1,3-phenyl core are reported and were found to exhibit atropisomerism. This was investigated in the solid state (X ray), in solution (NMR), and via computational studies. The synthesis of fluorinated G1 dendrimers allowed for the analysis of interconversion between conformations via 19F-19F EXSY NMR (exchange spectroscopy). These were shown to exist as two distinct sets of three interconverting atropisomers. Each atropisomer was identified as well as their respective interconversion pathway. By increasing the size of the core of the G1 dendrimers resulted in physical separation of atropisomers by preparative HPLC. Results suggest certain conformers are energetically unfavourable reducing the total number of atropisomers observed.