Tf2O-Promoted Morgan–Walls Reaction: From a Flexible Approach to Functionalized Phenanthridines and Quinazolines to the Short and Divergent Total Syntheses of Alkaloids
作者:Pei-Qiang Huang、Xiao-Yu Su
DOI:10.1055/a-1957-4343
日期:2023.3
dehydrative cyclization reaction. More importantly, a one-pot method was established for the direct and divergent synthesis of four types of phenanthridinoids from o-xenylamines, which features both a tert-N-formyl-o-xenylamine and phenanthridinium salt as key and versatile intermediates. The investigation has resulted in one of the shortest and the most efficient total syntheses of the three natural products
报道了一种在温和条件下将仲酰胺(N-酰基-邻苯二胺)直接转化为菲啶的新方案。该方法以三氟甲磺酸酐(Tf 2 O)/2-氟吡啶为高效酰胺活化体系,以MeCN或CH 2 Cl 2为溶剂。对于某些底物,MeCN 参与了反应,这为获得多取代的喹唑啉提供了温和的途径。通过采用 Tf 2 O/2,4,6-三叔丁基嘧啶 (TTBP) 组合,该方法扩展到N-甲酰-o-二甲苯胺,代表脱水环化反应的顽固酰胺底物类型。更重要的是,建立了一种从邻苯二胺直接和发散合成四种菲啶类化合物的一锅法,该方法以叔-N-甲酰-邻苯二胺和菲啶盐作为关键和通用的中间体。该研究导致了三种天然产物三球孢子苷、5,6-二氢双色胺和N-甲基辛西啶的最短和最有效的总合成之一,以及其他三种的正式全合成:3-羟基三球菌素、双色胺、和 zephycandidine A.