Synergistic Chiral Ion Pair Catalysts For Asymmetrically Catalytic Synthesis Of Quaternary α,β-diamino Acids

This thesis is composed of three parts:(1) Synergistic chiral organic ion pair catalysts are distinguished catalysts comparing with other organocatalysts. Synergistic chiral ion pair catalysis is a synthetic strategy wherein both the nucleophile and the electrophile are simultaneously activated by one catalyst to afford a single chemical transformation. This powerful catalysis strategy leads to several benefits, specifically synergistic catalysis can (i) introduce new, previously unattainable chemical transformations,(ii) improve the efficiency of existing transformations, and (iii) create or improve catalytic enantioselectivity where stereocontrol was previously absent or challenging.(2) The combination of a chiral phosphate anion with a silver ion has been demonstrated as a powerful and synergistic ion pair catalyst for aza-Mannich reaction addition of.N-tosyl aldimines with oxazolones. A series of valuable quaternary α,β-diamino acid derivatives was obtained with high yields (up to95%), diastereo-(up to25:1dr) and enantioselectivities (up to99%ee).(3) Asymmetric aza-Friedel-Crafts alkylation reaction of β-naphthol with N-Ts imine was examined. The aza-Friedel-Crafts products could be afforded in high yield and moderate enantiomeric excess under mild reaction conditions.