Tandem Pseudopericyclic Reactions: [1,5]-X Sigmatropic Shift/6π-Electrocyclic Ring Closure Converting <i>N</i>-(2-X-Carbonyl)phenyl Ketenimines into 2-X-Quinolin-4(3<i>H</i>)-ones
作者:Mateo Alajarín、María-Mar Ortín、Pilar Sánchez-Andrada、Ángel Vidal
DOI:10.1021/jo061286e
日期:2006.10.1
tube in the absence of solvent. The mechanism for the conversion of these ketenimines into quinolin-4(3H)-ones has been studied by ab initio and DFT calculations, using as model compounds N-(2-X-carbonyl)vinyl ketenimines bearing different X groups (X = F, Cl, OH, SH, NH2, and PH2) converting into 4(3H)-pyridones. This computational study afforded two general reaction pathways for the first step of the
N-(2-X-羰基)苯基酮亚胺在温和的热条件下经历[1,5]的X基团从羰基碳转移到酮亚胺片段的缺电子中心碳原子上,然后迁移6π -所得烯酮的-电子环闭环以顺序一锅法提供2-X-取代的喹啉-4(3 H)-one。测试的X基团是电子给体基团,例如烷硫基,芳硫基,芳基硒基,芳氧基和氨基。当涉及烷硫基,芳硫基和芳基硒基时,完全的转化在回流的甲苯中发生,而对于芳氧基和氨基,起始的烯酮亚胺必须在无溶剂的情况下在密封管中于230°C加热。这些酮亚胺转化为喹啉4(3 H)-已经通过从头算和DFT计算来研究,使用具有不同X基团(X = F,Cl,OH,SH,NH 2和PH 2)的N-(2-X-羰基)乙烯基酮亚胺作为模型化合物转化为4(3 H)-吡啶酮。该计算研究为序列的第一步提供了两个通用的反应途径,即[1,5] -X移位,具体取决于X的性质。当X为F,Cl,OH或SH时,迁移发生在协调模式,而当X为NH 2或PH