the cyclization mode is dependent on the length of the tethers. The reaction is limited to substrates containing terminal alkynes. A key step of the reaction is the intramolecular interception by an aromatic ring of the vinylmetal complex 2, which contains a cation center at the beta-position, generated from the electrophilic addition of transition metal halides toward an alkyne. The more electron-rich
用催化量的过渡
金属
氯化物如PtCl(2)处理芳基-1-
炔烃,例如4-芳基-
1-丁炔,5-芳基-
1-戊炔和6-芳基-
1-己炔和[RuCl(2)(CO)(3)](2),在80°C的
甲苯中进行环异构化,生成二氢
萘或二氢苯并
环庚烯,其中环化方式取决于系链的长度。该反应限于含有末端
炔烃的底物。该反应的关键步骤是
乙烯基金属配合物2的芳香环在分子内的拦截,该芳香环在β位置包含一个阳离子中心,这是由过渡
金属卤化物向
炔烃的亲电加成而产生的。较富电子的芳基体系更具反应性。