Syntheses of Ester-Substituted Norbornyl Palladium Complexes Ligated with tBu3P: Studies on the Insertion of exo- and endo-Monomers in the Ester-Substituted Norbornene Polymerization

Exo- and endo-isomers of an ester-substituted norbornene derivative [5-norbornene carboxylic acid methyl ester (NBE)] are compared in the addition polymerization using tBu3P-ligated palladium complex 1. The polymerization rate of endo-NBE is slower than that of the corresponding exo-NBE. Each of exo- and endo-NBE inserted complexes was synthesized and the insertion rate constant was determined for exo-NBE and endo-NBE. These experiments revealed that the consecutive exo-NBE insertion was faster than the consecutive endo-NBE insertion by 2-fold. On the other hand, in polymerization of an exo-NBE/endo-NBE (1:1) mixture, consumption rates of exo-NBE and endo-NBE were almost equal and the production rate of the poly-NBE from this mixture was almost the same as that of homopolymerization of exo-NBE.

本文对比研究了酯取代的环戊二烯衍生物（5-环戊二烯羧酸甲酯（NBE））的顺式和反式异构体在tBu3P配位的钯配合物1催化的加成聚合反应中的性能。结果显示，反式NBE的聚合速率低于相应的顺式NBE。针对顺式和反式NBE插入的复合物均进行了合成，并分别确定了顺式NBE和反式NBE的插入速率常数。实验表明，连续的顺式NBE插入速率比连续的反式NBE插入速率快两倍。另一方面，在顺式NBE/反式NBE（1:1）混合物的聚合反应中，顺式NBE和反式NBE的消耗速率几乎相等，且从该混合物中得到的聚NBE的生成速率与顺式NBE的均聚反应速率相近。