Synthesis of salen complexes containing ethylene glycol chains and their catalytic properties

Abstract

This thesis deals with preparation and study of manganese (III) complexes with novel chiral ligands containing ethylene glycol monomethyl ether and diethylene glycol monomethyl ether. The legands were synthesized from t-butythydroquinone in three steps with total yields of 20% and 24%, respectively. The complexation of the synthesized ligands with manganese (III) was accomplished by reacting the ligands with manganese diacetate in the presence of oxygen gas. Both complexes displayed similar asymmetric catalytic propertoes in the enantioselective epoxidation of alkenes under the homogeneous m-chloroperbezoic acd/N-methylmorpholine N-oxide and heterogeneous sodium hypochlorite/4-phenylpyridine N-oxide oxidative conditions. While only mediocre yields (60-88%) and enantioselectivity (50-65% ee) were observed in the epoxidation of styrene, high yields (>85%) and enantioselectivity (>90% ee) were achieved in the expoxidation of indene.