Synthesis and application of novel chiral 4,4' PheBOX ligands in asymmetric catalysis and Immobilisation study using 2,2'-PyBOX

Abstract

A great deal is known about the reactivity of catalysts derived from 2,2'-PyBOX and 2,2'-PheBOX ligands in asymmetric reactions. The initial aim of this research was to investigate a new type of bisoxazoline ligand, where the chiral centres are adjacent to the aromatic core of the ligand, rather than just in the chiral side arms, as in the traditional ligands. This thesis documents the design and synthesis of novel 4,4' PheBOX ligands (4,4'-phPHeBOX, 4,4'-MePhBOX and 4,4'-n-propylPheBOX) and attempted synthesis of 4,4'-PyBOX ligands. Metal complexes of the synthesised ligands were also tested in asymmetric reactions. The second part of this study involved an immobilisation study using 2,2'-PyBOX ligands combined with metal salts, which were electrostatically immobilised on silica gel. These immobilised catalysts were then tested in asymmetric propargylic substitution reactions, asymmetric trimethylsilylation reactions and asymmetric ring opening of expoxides.