Überraschende selektivitäten bei der cycloadditior von α,β-ungesättigten nitrilen an trifluormethyl-substituierte hetero-1,3-diene
作者:Klaus Burger、Wolfgang Schöntag、Ulrike Wassmuth
DOI:10.1016/s0022-1139(00)81495-5
日期:1983.1
4,4-Bis(trifluoromethyl)-1,3-diazabuta-1,3-dienes 1 as well as 4,4-bis(trifluoromethyl)-1-oxa-3-azabuta-1,3-dienes 2 with α,β- unsaturated nitriles (methacrylonitrile, crotononitrile, cinnamo-nitrile, phenylacetylenecarbonitrile) react to give [4+2]-cycloadducts. The cycloaddition process was found to occur across the CN triple bond exclusively, with formation of 4,4-bis(trifluoromethyl)- 1,4-dihydro-1
4,4-双(三氟甲基)-1,3-二氮杂丁-1,3-二烯1以及4,4-双(三氟甲基)-1-氧杂-3-氮杂-1,3-二烯2 β-不饱和腈(甲基丙烯腈,巴豆腈,肉桂腈,苯乙炔腈)反应生成[4 + 2]-环加合物。发现环加成过程仅在整个CN三键上发生,形成4,4-双(三氟甲基)-1,4-二氢-1,3,5-三嗪5和4,4-双(三氟甲基)- 4H-1,3,5-恶二嗪6,7。