Asymmetric Synthesis of #alpha#-#beta#-Dialkyl-#alpha#-phenylalanines via Direct Alkylation of a Chiral Alanine Derivative with Racemic #alpha#-Alkylbenzyl Bromides.A Case of High Enantiomer Differentiation of Room Temperature

摘要

This study demonstrates that the direct alkylation of a Ni(II)-complex of the chirla Schiff base of alanine with (S)-o-[N-(N-bnezylprolyl)amino]-benzophenone,with racemic #alpha#-alkylbenzyl bromides,is a synthetically feasible and methodologically advantageous approach to the target #alpha#,#beta#-dialkylphenylalanines over previously reported methods.For the first time we report and rationalize a case of a high enantiomer differentiation process at room temperature.