Pyrazoles and<i>C</i>-Imidoylaziridines through [4+1] Annulation and [2+1] Cycloaddition of 1-Azabuta-1,3-dienes with a Synthetic Equivalent of Phthalimidonitrene
作者:Aleksandr Stukalov、Viktor V. Sokolov、Vitalii V. Suslonov、Mikhail A. Kuznetsov
DOI:10.1002/ejoc.201700172
日期:2017.5.10
[4+1] annulation. This transformation is supposed to proceed by nitrenoid attack onto a lone pair of electrons of the imine nitrogen atom to give the vinylazomethine imine, followed by its 1,5-electrocyclization into pyrazoline and further aromatization into pyrazole. Rare examples of 2-imidoyl-1-phthalimidoaziridines that are formed by competitive [2+1] cycloaddition onto the C=C bond were isolated
N-氨基邻苯二甲酰亚胺与 1,2,4-triaryl-1-azabuta-1,3-diene 的氧化加成,在大多数情况下,导致 1,3,5-三芳基吡唑以中等至良好的产率通过 [4 +1] 年化。这种转化应该是通过类氮烯攻击亚胺氮原子的一对孤对电子来进行的,得到乙烯基偶氮甲碱亚胺,然后将其 1,5-电环化成吡唑啉并进一步芳构化成吡唑。对于在亚胺氮原子上具有缺电子芳基取代基的 1-氮杂二烯,通过在 C=C 键上的竞争性 [2+1] 环加成形成的 2-imidoyl-1-phthalimidoaziridines 的罕见例子以低产率分离。