Total synthesis of (−)-epimyrtine by a gold-catalyzed hydroamination approach

Abstract

SummaryA new approach to the total synthesis of (−)-epimyrtine has been developed from D-alanine. The key step to access the enantiopure pyridone intermediate was achieved by a gold-mediated cyclization. Finally, various transformations afforded the natural product in a few steps and good overall yield.

On the Nature of Interactions between Ionic Liquids and Small Amino‐Acid‐Based Biomolecules

“…In particular, Gong at al. have developed a direct conversion of o ‐(2‐propynyl)anilines into tetrahydroquinolines catalyzed by both Au I and Au III catalysts,21 whereas Gouault et al recently used Au I salts in the hydroamination step for the cyclization of asymmetric N ‐ tert ‐butoxycarbonyl (Boc) β‐aminoynones into chiral N ‐Boc‐substituted pyridones 22. Herein we report the catalytic activity of several gold derivatives towards the synthesis of 2‐substituted 4‐quinolones (Scheme ).…”

Research Progress in Non-noble Metals Catalyzed Hydroamination of Alkyenes and Alkynes

“…咪 唑并[1,2-a]吡啶是唑吡坦、阿吡坦等、沙立吡坦等很多 抗焦虑药的母环, 它的一种合成方法就包括了铜催化下 炔丙基胺基吡啶中间体的 5-exo-dig 分子内氢胺化环合 这一关键步骤(Scheme 3, c) [14] . 此外, 欧洲越橘的活性 成分 Epimyrtine [15] 、分离自土曲霉 Corymbosa porantherida 的活性生物碱 Porantheridine [16] 、提取自黄精属 和牧豆树属植物的苦马豆碱 [17] 、分离自海洋真菌土曲霉 的 Terreusinone [18] 、中药黄皮的活性成分肉桂酰胺 B 图式 5 氢胺化反应的两种催化机理 Scheme 5 Two general mechanisms of hydroamination 金属复合物 1b 是一种十分不稳定的物质, 可以立刻被 体系中其它连有氢的胺质子化并转移碱金属至另一分 子胺上重新生成 1a [27] , 从而使催化过程循环(Scheme 6).…”

Gold‐Catalyzed Hydrofunctionalizations and Spiroketalizations of Alkynes as Key Steps in Total Synthesis

“…The constituents of the fire ant Isosolenopsin and Isosolenopsin A could be synthesized from compounds 38 (Isosolenopsin) and 39 (Isosolenopsin A), respectively (Scheme a) . The quinolizidine alkaloid from Vaccinium myrtillus (−)‐Epimyrtine was prepared in a similar manner, albeit slightly elevated temperatures (40 °C) were necessary to drive the reaction …”