Low symmetry metal complexes: Chloro cysteine ethyl ester-N,S triphenylphosphine palladium(II), a new regioselective hydrocarboxylation catalyst for 2-phenylpropanoic acid, and its crystal structure

The hydrochlorides of cysteamine, cysteine ethyl ester and penicillamine methyl ester, react with Pd(PPh3)4 to yield low symmetry complexes of palladium(II) that incorporate the N,S-aminothiolato ligand and triphenylphosphine; the complex with cysteine ethyl ester, structurally characterized by X-ray diffraction, proved to be an effective catalyst for the hydrocarboxylation of styrene with high selectivity (98%) towards 2-phenylpropanoic acid.