Regioselective generation of iminium cation by PET processes: Its in situ trapping by intramolecular nucleophiles and synthesis of some biologically active heterocycles.
作者:Ganesh Pandey、G. Kumaraswamy、P.Yella Reddy
DOI:10.1016/s0040-4020(01)80497-x
日期:1992.1
Efficient, mild and direct route for regiospecific iminium cation is developed by sequential two electron oxidation of several N-alkylated tertiary amines by photoinduced electron transfer processes. The regiospecificity of iminium cation arises from the deprotonation step of amine radical cation to generate α-amino radical which depends on the stereoelectronic factor subject to kinetic acidity of
通过光诱导的电子转移过程,对几个N-烷基化的叔胺进行连续的两次电子氧化,从而开发出了高效,温和且直接的区域特异性亚胺阳离子途径。亚胺阳离子的区域特异性来自胺自由基阳离子的去质子化步骤以产生α-氨基自由基,该α-氨基自由基取决于受胺自由基阳离子的动力学酸度影响的立体电子因子。亚铵阳离子被有效地俘获原位通过内部nuleophiles,得到环状化合物14-18和22A-C 。顺式α,α'-二烷基化哌啶和吡咯烷30a–c的立体选择性合成是通过亲和性打开四氢-1,3-恶嗪22a–c实现的。