Tetronamides as Latent Acyclic Vinylogous Amides in Formal <i>Aza</i>-[3 + 3] Cycloaddition Reactions with α,β-Unsaturated Iminium Salts. An Unexpected Rearrangement and an Approach to Synthesis of Substituted Piperidines
作者:Nadiya Sydorenko、Richard P. Hsung、Ossama Saleh Darwish、Juliet M. Hahn、Jia Liu
DOI:10.1021/jo049108d
日期:2004.10.1
A detailed account regarding formal aza-[3 + 3] cycloaddition reactions of tetronamides with α,β-unsaturated iminium salts is described here. This investigation uncovers regioisomeric cycloadducts that were not found in previous studies involving this formal cycloaddition and an unexpected rearrangement that led to pyridines and dihydropyridines. Both stereochemical and regiochemical issues raised
在此描述有关四酰胺与α,β-不饱和亚胺盐的形式氮杂-[3 + 3]的正式氮杂-[3 + 3]环加成反应的详细说明。这项研究发现了以前的研究中未发现的区域异构体环加合物,该研究涉及这种正式的环加成反应以及导致吡啶和二氢吡啶的意外重排。这项研究中提出的立体化学和区域化学问题都为该环加成反应提供了进一步的机械学见解。通过小心地控制反应温度,获得了所需的形式的环加合物。随后将这些环加合物转化为官能化的哌啶,确立了将四氨酰胺用作潜在的无环乙烯基酰胺类化合物的形式,用于形式的氮杂-[3 + 3]环加成反应。