Synthesis of a Chiral β-Amino Acid Derivative by a Cobalt-Catalysed Coupling Reaction

A chiral β-amino acid derivative was synthesised by a cobalt-catalysed alkylation of 2,4,5-trifluorophenyl magnesium bromide with the alkyl halide derivative of L-aspartic acid, using an efficient catalytic reagent: CoCl 2 /TMEDA. The halide derivative was synthesised from protected L-aspartic acid β-methyl ester and the Grignard reagent was made by bromine- magnesium exchange. The stereo-structure was well preserved from L-aspartic acid.