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.
为研究以合成聚酮高分子寻找高效廉价的催化体系,制备了5%的活性碳负载钯多相催化剂,并首次将其用于催化苯乙烯与CO共聚合成聚酮(PK)的反应中.采用红外光谱、元素分析、13CNM R和热重分析等手段对苯乙烯/CO共聚产物的结构和性质进行了表征.分别讨论了在钯碳催化剂作用下,含氮配体以及助催化剂强酸等因素对共聚反应的影响,并评价了钯碳催化剂在苯乙烯与CO共聚反应中的循环使用效果.实验结果表明,在温度为65℃,CO压力为3.0M Pa的条件下,当使用2,2′-联吡啶为配体,三氟甲基磺酸为助催化剂时,钯碳催化苯乙烯与CO共聚反应的活性可达4.65×103g PK/(m o lPd.h),共聚产物的重均分子量(Mw)可达9.32×103g/m o l,数均分子量(M n)可达5.23×103g/m o l.
