Chemo, regio, and stereoselectivity in olefination of hydrazone 1,4-adducts between conjugated azoalkenes and sulphur co-activated methylene compounds
作者:Orazio A Attanasi、Lucia De Crescentini、Paolino Filippone、Giuseppe Gatti、Fabio Mantellini、Stefania Santeusanio
DOI:10.1016/s0040-4020(98)00392-5
日期:1998.6
hydrazone derivatives by 1,4-addition. In some cases these hydrazones were isolated, while in others their formation is accompanied by olefination products. Under the same reaction conditions and/or in methanol by means of gentle heating, several of these adducts give rise to the related α,β-olefinated hydrazone derivatives as pure isomeric forms or as mixtures by loss of the nitro, sulphonyl or sulphinyl
在催化量的甲醇钠存在下,共轭偶氮烯烃在室温下平稳地添加(苯基磺酰基)乙酰胺,(苯基磺酰基)乙酸甲酯,(苯基磺酰基)乙酸甲酯,(芳磺酰基)乙腈,双(苯基磺酰基)甲烷和(芳磺酰基)硝基甲烷通过1,4-加成得到相应的α-官能化衍生物。在某些情况下,这些被分离出来,而在另一些情况下,它们的形成伴随有烯烃化产物。在相同的反应条件下和/或在甲醇中通过缓慢加热,这些加合物中的几种会以纯异构体形式或以失去硝基,磺酰基或亚磺酰基的混合物。值得注意的是,对于β-氰基-β-芳基磺酰基加合物,主要检测到消除了提供β-氰基-α,β-烯化的芳基磺酰基,而对于类似的β-硝基-β-芳基磺酰基加合物,则主要观察到损失硝基部分,产生β-芳基磺酰基-α,β-烯化ated。