Chemistry of tetra-alkoxyethenes. Part VII. Thermal [2 + 2] cyclo-additions with 1-cyanobutadienes
作者:Pieter H. J. Ooms、Mat A. Bertisen、Hans W. Scheeren、Rutger J. F. Nivard
DOI:10.1039/p19760001538
日期:——
Acyclic 1-cyanobutadienes (2) having a second electron-withdrawing substituent at C-1 behave towards tetra-alkoxyethenes (1) like equally substituted simple olefins. The normal product is a [2 + 2], not a [4 + 2] cyclo-addition product. The correspondence in reactivity of these electron-poor olefins and butadienes towards the nucleophilic tetra-alkoxyethenes is further exemplified by the similarity
在C-1处具有第二个吸电子取代基的无环1-氰基丁二烯(2)像同等取代的简单烯烃一样对四烷氧基乙烯(1)起作用。正常乘积是[2 + 2],而不是[4 + 2]环加成产物。这些贫电子的烯烃和丁二烯对亲核四烷氧基乙烯的反应性的对应性进一步通过取代基对环加成的相似作用来例证。给出了可能的解释。