Ligand-free palladium catalysed Heck reaction of methyl 2-acetamido acrylate and aryl bromides as key step in the synthesis of enantiopure substituted phenylalanines

A range of substituted aryl bromides were coupled with methyl 2-acetamido acrylate using ligand-free palladium catalysis. Subsequently asymmetric hydrogenation with Rh/MonoPhos yielded substituted phenylalanines in high enantioselectivities (e.e. 92–99%).