Synthesis of Highly Substituted 3-Formylfurans by a Gold(I)-Catalyzed Oxidation/1,2-Alkynyl Migration/Cyclization Cascade
作者:Tao Wang、Shuai Shi、Max M. Hansmann、Eva Rettenmeier、Matthias Rudolph、A. Stephen K. Hashmi
DOI:10.1002/anie.201310146
日期:2014.4.1
3‐Formylfuran derivatives are core structures of a variety of bioactive natural products. However, procedures for their preparation are still rare and generally inefficient in terms of atom economy: These methods require multiple steps or harsh reaction conditions and show selectivity problems. An efficient gold(I)‐catalyzed cascade reaction that leads to 3‐formylfurans from easily accessible starting
3-甲酰呋喃衍生物是多种生物活性天然产物的核心结构。但是,制备它们的程序仍然很少见,并且就原子经济性而言通常是低效的:这些方法需要多个步骤或苛刻的反应条件,并显示出选择性问题。现在描述一种有效的金(I)催化的级联反应,该反应可从易于获取的起始原料生成3-甲酰呋喃。在N存在下,从相应的对称和不对称的1,4-二炔-3-醇中获得了多种3-甲酰基呋喃氧化效果好至极佳。同位素标记实验以及DFT计算都支持一种机制,在这种机制下,在最初的氧转移后,1,2-炔基迁移比氢化物转移更有利;随后进行环化以提供所需的官能化的呋喃核。