derivatives was examined to give N-phenyl-N′-vinylcarbodiimide and its derivatives, all of which underwent a [4+2] cycloaddition reaction with electron-rich dienophiles (enamines) and/or electron-deficient dienophiles (activated acetylenes), resulting in the formation of a pyridine ring system. The regioselectivity of the cycloaddition reaction could be rationalized on the basis of a frontier orbital
研究了(
乙烯基亚
氨基)三
苯基正膦及其几种衍
生物的
氮杂-维蒂希反应,得到了 N-
苯基-N'-
乙烯基碳二
亚胺及其衍
生物,所有这些都与富电子亲二
烯体(
烯胺)发生了 [4+2] 环加成反应和/或缺电子的亲二
烯体(活化的
乙炔),导致形成
吡啶环系统。环加成反应的区域选择性可以在前沿轨道考虑的
基础上合理化。