The cycloisomerization of 1,6-enynes catalyzed by rhodium(III) porphyrin under mild reaction conditions successfully afforded a five-membered ring system. The rhodium porphyrin was found to be a strong π-Lewis acid that could activate alkynes. Thus, rhodium porphyrin-catalyzed intramolecular Friedel–Crafts-type reactions of alkynes with arenes were also accomplished. Furthermore, rhodium porphyrin-catalyzed intermolecular cyclization of alkynes with styrenes afforded the indene derivatives.
在温和反应条件下,由
铑(III)
卟啉催化的1,6-烯炔的环异构化成功地生成了五元环结构。研究发现,
铑卟啉是一种强的π-
路易斯酸,能够活化
炔烃。因此,
铑卟啉催化的
炔烃与
芳烃的分子内弗里德尔-克拉夫茨类型反应也成功实现。此外,
铑卟啉催化的
炔烃与
苯乙烯的分子间环化反应生成了
茚衍
生物。