The influence of imine structure, catalyst structure and reaction conditions on the enantioselectivity of the alkylation of alanine methyl ester imines catalyzed by Cu(ch-salen)

Systematic variation of the substrate structure has shown that the most effective substrates for Cu(ch-salen)-catalyzed asymmetric enolate alkylation reactions carried out under phase-transfer conditions are the para-chlorophenyl imines of amino esters. The other reaction parameters (solvent and stirring speed) have also been optimized. The introduction of substituents onto the aryl rings of the salen ligand was found not to have a beneficial effect on the enantioselectivity of the reaction.