Thermal and catalytic isomerization of exomethylenecycloheptadienes. Experimental and theoretical studies
作者:Yukiko Fukusaki、Jun Miyazaki、Isao Azumaya、Kosuke Katagiri、Shinsuke Komagawa、Ryu Yamasaki、Shinichi Saito
DOI:10.1016/j.tet.2009.10.065
日期:2009.12
intermolecular [3+2+2] cycloaddition reaction of ethyl cyclopropylideneacetate with alkynes proceeded in the presence of a Ni(0)/PPh3 catalyst, and cycloheptadiene derivatives were obtained. However, in the reaction of 1-cyclopropylidene-2-propanone with phenylacetylene, a cycloheptatriene derivative was isolated. It was anticipated that the isomerization of the initially formed cycloheptadiene derivative
在Ni(0)/ PPh 3催化剂的存在下进行环亚丙基乙酸乙酯与炔烃的分子间[3 + 2 + 2]环加成反应,得到环庚二烯衍生物。但是,在1-环亚丙基-2-丙烷与苯乙炔的反应中,分离出环庚三烯衍生物。预期最初形成的环庚二烯衍生物的异构化导致环庚三烯衍生物的形成。在本文中,我们报告了环庚二烯衍生物在热,酸性和碱性条件下的异构化。还通过理论计算研究了产品的稳定性。讨论了取代基的作用和异构化的机理。