The double carbonylation of benzyl chloride catalyzed by cobalt complex is studied.The catalytic system are composed of cobaltous chloride and pyrazinyl ligands or pyridyl ligands,respectively.Among pyridyl ligands,Pyridine-2-carboxylate anionPyca^- has the highest catalysis activity with the yield of phenylpyruvic acidPPA 69.2%.When there is an electron attractive group on the pyridine ring of pyridine monocarboxylic acid,the products are PPA,and with the group’ electron attractivity increasing,the catalysis activity of the catalytic system is decreased.When ligands are pyrazinyl anions,the products are β-benzyl-α-phenylpyruvic acidBPPA.Thereinto,Pyrazine-2-carboxylate anionPzca^- has the highest catalysis activity with the yield of β-benzyl-α-phenylpyruvic acidBPPA 56.8%.The catalysis systems with pyrazinyl or pyridyl acids have not catalysis activity at all.When ligand is the mixture of nPzca^-∶nPyca^-=1∶1,BPPA yield reaches 72.7%,and the reaction rate is between two ligands to be separately used.These experiment results are discussed in detail.
