Novel synthesis of substituted pyrrolidines and piperidines via radical addition–ionic cyclization reaction of oxime ethers
作者:Okiko Miyata、Shinya Takahashi、Akira Tamura、Masafumi Ueda、Takeaki Naito
DOI:10.1016/j.tet.2007.11.081
日期:2008.2
have developed a novel synthetic route to nitrogen-containing heterocycles via radical addition–ionic cyclization reaction. Treatment of oxime ethers carrying the tosyloxy group with Et3B and alkyl iodide in the presence of Lewis acid gave the substituted pyrrolidines and piperidines. The reaction of oxime ethers carrying the methoxycarbonyl group proceeded under the same conditions to give the amino
我们已经开发出了一种通过自由基加成-离子环化反应合成含氮杂环的新颖合成途径。在路易斯酸存在下用Et 3 B和烷基碘处理带有甲苯磺酰基的肟醚,得到取代的吡咯烷和哌啶。带有甲氧基羰基的肟醚的反应在相同条件下进行,得到氨基酯,通过用浓盐酸处理,氨基酯很容易转化为相应的内酰胺。另一方面,带有苯氧羰基的肟醚在自由基反应条件下直接提供烷基化的内酰胺。该多米诺反应的实用性通过合成(±)-古吉茄碱和5,8-二取代的吲哚利兹定生物碱的形式合成得到证明。