Similarly to aldehydes [6] ketones form 3-oxazolines via cyclo-addition to the benzonitrile-methylides 2 that arise photochemically from the 3-phenyl-2H-azirines 1. With various ketones benzonitrile-isopropylide (2a) gives cyclo-addition products in very good preparative yields (scheme 1). Benzonitrile-ethylide (2c) and benzonitrile-benzylide (2b) [8] react, however, sluggishly with ketones, smooth
与
醛类似,[6]酮通过环加成苯并腈-甲基化物2形成3-
恶唑啉,该
苯甲腈-甲基化物2从光
化学上由3-苯基-2 H-
叠氮基1生成。用各种酮,
苯甲腈-异丙基化物(2a)以非常好的制备产率(方案1)提供环加成产物。
苯甲腈-乙(2c)和
苯甲腈-苄基(2b)[8]反应缓慢,但与酮反应缓慢,仅在与“活化”酮(
2,2,2-三氟苯乙酮, 1,1,1-三
氟-2-
丙酮)。与1a的
丙酮基
丙酮形成双加合物12