Asymmetric synthesis of alpha,beta-dialkyl-alpha-phenylalanines via directalkylation of a chiral alanine derivative with racemic alpha-alkylbenzyl bromides. A case of high enantiomer differentiation at room temperature

[GRAPHICS] This study demonstrates that the direct alkylation of a Ni(II)-complex of t he chiral Schiff base of alanine with (S)-o-[N(N-benzylprolyl)amino]-benzop henone, with racemic alpha -alkylbenzyl bromides, is a synthetically feasib le and methodologically advantageous approach to the target alpha,beta -dia lkylphenylalanines over previously reported methods. For the first time we report and rationalize a case of a high enantiomer differentiation process at room temperature.