1,3-Dipolar Cycloadditions to Bicyclic Olefins. I. 1,3-Dipolar Cycloadditions to Norbornadienes
作者:Hisaji Taniguchi、Toshikazu Ikeda、Yoshihiro Yoshida、Eiji Imoto
DOI:10.1246/bcsj.50.2694
日期:1977.10
The 1,3-dipolar cycloadditions of phenylglyoxylonitrile oxide, benzonitrile-N-phenylimine, or N-phenyl-C-p-nitrophenylnitrone to norbornadiene, 2,3-dicyanonorbornadiene, and 2,3-bis(methoxycarbonyl)norbornadiene give the endo-adducts, together with the exo-adducts. These findings show that the 1,3-dipolar cycloadditions to norbornadienes do not follow the “exo rule.” It is suggested that the present 1,3-dipolar cycloadditions are kinetically controlled reactions. The endo-side of norbornadienes is found to be homoconjugated by their NMR spectra. The homoconjugation must be responsible for the observed phenomenon.
苯基二氧四氢噁烷、苯腈-N-苯胺或N-苯基-C-p-硝基苯基氮酰胺与挠度二烯、2,3-二氰挠度二烯和2,3-双(甲氧羧基)挠度二烯的1,3-偶极环加成反应生成了内加成产物及外加成产物。这些发现表明,对挠度二烯的1,3-偶极环加成反应并不遵循“外加成规则”。建议当前的1,3-偶极环加成反应是动力学控制的反应。通过其核磁共振(NMR)谱发现挠度二烯的内侧为同共轭的。同共轭效应必须是造成观察到现象的原因。