Photoreactions of β-aziridinylacrylonitriles and acrylates with alkenes: formation of head-to-head adducts and application to the preparation of pyrrolizidine alkaloid
作者:Keitaro Ishii、Takuya Sone、Yukio Shimada、Takahide Shigeyama、Masahiro Noji、Shigeo Sugiyama
DOI:10.1016/j.tet.2004.09.031
日期:2004.11
The photochemical C,C-bond cleavage of N-benzyl β-aziridinylacrylonitrile 1 and acrylate 2 and the subsequent [3+2] cycloaddition with electron-deficient alkenes afforded head-to-head adducts selectively and efficiently. Irradiation of N-phenyl aziridine 3 with acrylonitrile gave adducts, but photoreaction of N-benzoyl aziridine 4 and thermal reactions of 3 and 4 with alkenes yielded C(γ),N-cleaved
N-苄基β-叠氮基丙烯腈1和丙烯酸酯2的光化学C,C键裂解以及随后的[3 + 2]与缺电子烯烃的环加成反应可选择性且高效地提供头对头加合物。N-苯基氮丙啶3用丙烯腈辐照得到加合物,但N-苯甲酰基氮丙啶4的光反应以及3和4与烯烃的热反应产生C(γ),N裂解的产物,而不是环加合物。N-三苯甲基氮丙啶5也与缺电子的烯烃反应,得到2,3-顺式-吡咯烷衍生物。以方便的方式实现了从5开始的吡咯烷核生物碱异戊烯醇(27)的正式合成。