inolines. Irrespective of the electronic properties of the N-phenyl substituent the less reactive ferrocene-based imines were directly converted into quinoline products. The intermediate iodoiminium ions were analysed by B3LYP/DGZVP calculations suggesting stepwise mode for the cycloaddition process. In one case the regioselectivity of the second step of cycloaddition was also interpreted by DFT analysis
在碘催化和微波辐射的同时作用下,分别通过给电子C-吩噻嗪基-和二茂铁基取代基使希夫碱失活,从而进行了3,4-二氢-2的正式逆电子需量氮杂-狄尔斯-阿尔德(DA)环加成反应H-吡喃(DHP)用作供体组分。取决于N-苯基的取代方式,含吩噻嗪的亚胺的反应得到2 H-吡喃并[3,2- c ]喹啉或3-(3-羟丙基)喹啉。不论N的电子性质如何-苯基取代基反应性较低的二茂铁基亚胺直接转化为喹啉产物。通过B3LYP / DGZVP计算分析了中间碘代亚胺离子,提示了环加成过程的逐步模式。在一种情况下,还通过对最初形成的DHP加合物的其他旋转异构体进行DFT分析来解释第二步环加成反应的区域选择性。