The conditions for the thermolysis of furoxans annulated with differently strained five-membered carbocycles (cyclopentafuroxan 1, norbornenofuroxan 2, and acenaphthofuroxan 3) to bis(nitrile oxides) in the presence of various dipolarophiles (diethyl acetylenedicarboxylate, benzoylformonitrile, and ethoxycarbonylformonitrile) were optimized. It was found that the reactivities of the above furoxans as sources of bis(nitrile oxides) decrease in the order 2 > 1 > 3. Among the furoxans studied, only norbornenofuroxan 2 can be recommended as a possible cross-linking reagent for polymers. The formation of di-N-oxides of 3,4-bis(cyanopropyl)-, 3,4-bis(cyanocyclopentyl)-, and 3,4-bis(cyanonaphthyl)furoxans was detected. They resulted from intermolecular cyclodimerization of bis(nitrile oxides) initially formed in the thermolysis of furoxans 1–3.
在各种偶极体(
乙炔二
羧酸二
乙酯、苯甲酰甲腈和乙氧羰基甲腈)的作用下,对环戊并
呋喃(环戊并
呋喃1、
降冰片烯并
呋喃2和
苊并
呋喃3)与不同强度的五元碳环(双(腈基氧化物))的热解条件进行了优化。结果发现,上述
呋喃作为双(腈基氧化物)来源的反应活性按2>1>3的顺序递减。在研究的
呋喃中,只有
降冰片烯并
呋喃2可以作为聚合物的交联试剂。检测到3,4-双(
氰基丙基)-、3,4-双(
氰基环戊基)-和3,4-双(
氰基萘基)
呋喃二-N-氧化物的形成。它们是由
呋喃1-3的热解中最初形成的双(腈基氧化物)分子间环二聚化产生的。