Cyclization of aminyl radicals generated by anodic oxidation of lithium alkenylamides. Stereo- and regioselective synthesis of cis-l-alkyl-2, 5-disubstituted pyrrolidines
作者:Masao Tokuda、Yasufumi Yamada、Toshiya Takagi、Hiroshi Suginome、Akio Furusaki
DOI:10.1016/s0040-4020(01)89956-7
日期:——
regioaelective cyclization to give -1-alkyl-2, 5-disubatituted pyrrolidines (5c–5h) in moderate yields. The stereochemistry of 5c–5h was confirmed by comparison with the corresponding -1-allkyl-2, 5-disubstituted pyrrolidines which were prepared by aminomercuration of 1c–1h. The structure of -1,2-dimethyl-5-phenylpyrrolidine (17) was established by an X-ray crystallographic analysis of its ammonium bromide
发现由烯基锂锂(2)的阳极氧化产生的中性氨基自由基(3)经历了立体和区域电环化反应,从而以中等收率得到了-1-烷基-2,5-二取代的吡咯烷(5c-5h)。通过与1c-1h的氨基汞合成制备的相应的-1-烷基-2,5-二取代的吡咯烷进行比较,证实了5c-5h的立体化学。通过对其溴化铵21进行X射线晶体学分析,确定了-1,2-二甲基-5-苯基吡咯烷(17)的结构。。在这项研究中检查的各种氨基自由基被发现仅与它们的双键内部碳原子结合,形成一个五环(5a-5l)或六元环(13)。从N-甲基-1-苯基丁-3-烯基胺(14)没有获得由环化产生的产物。