General synthetic approach towards annelated 3a,6-epoxyisoindoles by tandem acylation/IMDAF reaction of furylazaheterocycles. Scope and limitations
作者:Fedor I. Zubkov、Eugenia V. Nikitina、Timur R. Galeev、Vladimir P. Zaytsev、Victor N. Khrustalev、Roman A. Novikov、Daria N. Orlova、Alexey V. Varlamov
DOI:10.1016/j.tet.2014.01.008
日期:2014.2
investigated. The obtained Diels–Alder adducts are attractive and useful substrates for further transformations. Fused isoindoles can be prepared from them in one-step by aromatization of the 7-oxabicyclo[2.2.1]heptene ring. Other transformations, including halogenation, ring cleavage, and Wagner–Meerwein skeletal rearrangement, are also demonstrated. The spatial structures of the obtained compounds have
提出了与恶嗪,恶唑,噻嗪,噻唑,嘧啶片段及其苯甲酰化类似物退火的3,6a-环氧异吲哚的一种有效且通用的一锅合成方法。该方法基于α,β-不饱和酸酐与α-呋喃基取代的氮杂杂环之间的串联N-酰化/分子内环加成反应(呋喃的分子内Diels-Alder反应,IMDAF)。后者可通过将各种糠醛与1,2-或1,3-N,X-双亲核试剂(氨基醇,氨基硫醇,二胺)缩合而轻松制备。观察到的IMDAF反应是立体选择性的:仅在非对映异构体之一普遍存在的情况下才形成外加合物。在大多数情况下,缩合/ N-酰化/ IMDAF反应顺序可以通过一锅多米诺协议进行。对该方法的范围和局限性进行了彻底的研究。所获得的Diels–Alder加合物是诱人且有用的底物,可用于进一步转化。熔融异吲哚可通过将7-氧杂双环[2.2.1]庚烯环芳构化而一步一步制得。还显示了其他转化,包括卤化,环裂解和Wagner-Meerwein骨架重排。通过