新颖的纳米镍催化芳基硼酸与芳基溴的偶联反应

A Novel Cross-coupling Reaction of Arylboronic Acid and Arylbromide Catalyzed by Nano Nickel

纳米镍用于催化芳基硼酸与芳基溴的偶联反应 ,合成了一系列 4 ,4′ 双烷基环己基联苯类液晶。纳米镍在相转移剂十六烷基三甲基溴化铵的存在下回流反应 1 5h ,目的产物的收率为 60 %～65 %。讨论了纳米镍催化偶联反应的可能活性位。镍催化剂经SEM EDS表征平均粒径为 80nm ,定量分析表明氧含量为 33% ;XRD测试结果表明纳米镍体相以单质态存在 ,但其特征谱线的d值普遍增大 ;由XPS分析得出纳米镍的结合能 ( 2p3 2 和 2p1 2 )为 85 4 .1eV和 871 .8eV ,峰间距为 1 7.7eV 。

Synthesis route of the liquid crystal compound 4,4′ bis(trans 4 alkylcyclohexyl) diphenyl in the presence of Cetrimonium bormide over nano Ni catalyst is reported. The cross coupling reaction of arylboronic acid with arylbromide is carried out under reflux temperature for 15h in yields 60% to 65%. The probably active site of the cross coupling reaction over nano Ni catalyst is investigated. The nano Ni catalyst is characterized by SEM EDS to give average particle size 80nm and oxygen content 33%. XRD measurement shows that the bulk phase of nano Ni is simple substance, whose d values of characteristic spectrum totally increase. XPS reveals that bonding energies (the 2p 3/2 and 2p 1/2 characteristic peak) of nano Ni are 854.1eV and 871.8eV respectively, and their pitch is 17.7eV. The nano Ni exists in a state between simple Ni and NiO.