Abstract

The polymerization of commercial strained cycloalkene, 5-ethylidene-2-norbornene, in the presence of Pd–N-heterocyclic carbene complexes (two of which are synthesized for the first time) containing phosphine or pyridine ligands is studied. Upon activation with borate Na⁺[B(3,5-(CF₃)₂C₆H₃)₄)]^–, the studied Pd complexes catalyze the polymerization of 5-ethylidene-2-norbornene according to the addition scheme. Polymerization proceeds selectively and involves only the endocyclic (norbornene) double bond of the monomer, while the exocyclic (ethylidene) double bond remains unaffected. Pd–N-heterocyclic carbene complexes with phosphine ligands are inactive in polymerization, while similar complexes with 3-chloropyridine ligands show a higher activity. Two new Pd complexes are synthesized.

中文翻译：

---

Pd-N-杂环卡宾与膦和吡啶配体的存在下5-乙叉-2-降冰片烯的聚合

摘要

研究了在含有膦或吡啶配体的Pd- N-杂环卡宾配合物（其中两个是首次合成）存在下，商业化的应变环烯烃5-亚乙基-2-降冰片烯的聚合反应。用硼酸盐Na ⁺ [B（3,5-（CF ₃）₂ C ₆ H ₃）₄）] ^-活化后，根据加成方案，所研究的Pd配合物可催化5-亚乙基-2-降冰片烯的聚合。聚合选择性地进行并且仅涉及单体的环内（降冰片烯）双键，而环外（亚乙基）双键保持不受影响。钯氮具有膦配体的-杂环卡宾配合物在聚合反应中是无活性的，而具有3-氯吡啶配体的类似物显示出更高的活性。合成了两个新的Pd配合物。