摘要
在相转移催化剂十六烷基三甲基溴化铵的助催化作用下 ,用PdCl2 催化芳基硼酸与溴代芳烃偶联反应合成了液晶化合物 4 戊基 (4′ 丙基环己基 )三联苯 ,反应转化率达到 93% ,反式产物选择性 86 %。结构经IR ,1HNMR和MS确证 ,并用DSC测定了此液晶的相变数据。考察了加料顺序和相转移催化剂对偶联反应的影响。提出了相转移条件下可能的催化循环机理 ,认为芳基硼酸是以ArB(OH)
Penty (4′ propylcyclohexyl)triphenyl was synthesized by cross coupling reaction of 4 (4′ penty)biphenyl boronic acid and 1 bromo 4 trans (4′ propyl)cyclohexyl benzene catalyzed by PdCl 2 in the presence of cetrimonium bromide with coversion 93% and selectivity 86%. The structure of the product was confirmed by IR, 1H NMR and MS and it's phase temperature was determined by DSC. The influences of additive sequence and phase transfer catalysis are investigated. The catalytic mechanism cycle of the cross coupling reaction promoted by PTC is proposed, in which arylboronic acid takes part by the means of ion form ArB(OH) 3 -.
出处
《合成化学》
CAS
CSCD
2001年第5期442-444,共3页
Chinese Journal of Synthetic Chemistry
