The synthesis of chiral bidentate (N,N), (N,P) and (N,O) ligands and their use in metal-mediated asymmetric carbon-carbon bond formation

Sammanfattning: This thesis covers three projects based on the metal-mediated formation of new chiral centers in the prescence of chiral ligands. The first project, involving (N,N)- ligands, concerns the synthesis of some (C2-symmetric bis(aziridine) ligands and the use of these in the addition of organolithium reagents to N-aryl protected imines leading to enantioselectivities of up to 89%. The reaction conditions have been varied with respect to temperature, organolithium:ligand ratio, organolithium reagent and substrate. Some attempts to gain insight into the mechanism were also made. The second project, with (N,O)-ligands, concerns the use of some analogs to NOBIN (nitrogen-oxygen BINOL) which have been tested in the addition of organozinc reagents to N-diphenylphopshinoyl imines giving enantioselectivities of up to 85%. The effect of deprotonation of the ligand with a base prior to addition of imine and organozinc reagent was also investigated. Some experiments to get insight into the reaction mechanism were made. The structure of possible ligand-substrate-metal complexes were suggested for the chiral intermediates for the first two projects, The third project, involving an (N,P)-ligand, deals with the synthesis and use of a new bidentate aziridinophospine ligand in asymmetric palladium-catalysed allylic alkylations.