Asymmetric reactions in ionic liquids and water using organocatalysts

Abstract

In this thesis, the atom-economic direct asymmetric organocatalytic aldol reaction and amine conjugate addition reaction in environmentally friendly solvents were developed: (1) Ionic liquid, 1-n-butyl-3-methylimidazolium hexafluorophosphate ([bmim] PF6) is a suitable solvent for proline-catalyzed asymmetric aldol reaction. Furthermore, the ionic liquid containing chiral catalyst L-proline can be reused without decrease in yield and selectivity. (2) Two kinds of new organocatalysts, exo-2-azabicyclo[2.2.1]heptane-3-carboxylic acid and dipeptides derived from L-proline, were developed. Exo-2-azabicyclo[2.2.1]heptane-3-carboxylic acid was found to be an efficient catalyst for direct asymmetric aldol reaction. The dipeptide-catalyzed aldol reaction in water gives the desired products with moderate enantioselectivity. (3) Conjugate addition of amines to I?, I?-ethylenic compounds were efficiently carried out in the environmentally friendly ionic liquid media under mild condition to provide an easy access to trifluoromethylated amines.