α-氨基在由叔丁基过氧化氢、脂肪族三烷基胺、卤代烃和碘化铜(I)的组合引发的反应中经历卤素原子抽吸形成卤甲基自由基。α-氨基自由基的形成避免了有利于卤素原子转移的优先氢原子转移,从而释放卤代甲基自由基以加成到烯烃中。所得自由基加成产物与叔丁基过氧基团相加形成 α-过氧-β,β-二氯丙苯产物,该产物可转化为其相应的 β,β-二氯醇和新型吡啶衍生物。计算分析清楚地解释了氯仿与传统 HAT 的偏差,并建立了正式的氧化加成/还原消除作为最低能量途径。
The application of vinylogous iminium salts and related synthons to the preparation of trisubstituted pyridines
作者:Scott A. Petrich、Fred A. Hicks、Doug R. Wilkinson、James G. Tarrant、Steve M. Bruno、Marian Vargas、Kirsten N. Hosein、John T. Gupton、James A. Sikorski
DOI:10.1016/0040-4020(94)01039-3
日期:1995.2
The reaction of unsymmetrical vinylogous iminum salts and related analogs with β-aminocrotononitrile to yield 2,3,6-trisubstituted pyridines with regioselective control is described.
Nucleophilic recyclization of pyridinium salts involving a CCN interchange ringtransformation for the synthesis of 2-methylnicotinonitrile derivatives was herein developed. 3-Aminocrotononitrile (3-ACN) produced in situ from CH3CN acted as a C-nucleophile, as well as the source of CH3 and CN groups, which was supported by isotope-labeling and control experiments.