Iron‐Catalyzed Reductive Cyclization of Alkenyl Vinylogous Carbonates for Stereoselective Synthesis of Substituted Tetrahydrofurans, Tetrahydropyrans, and Chromans
作者:Santosh J. Gharpure、Rupali S. Chavan、Ajaykumar V. Ardhapure
DOI:10.1002/adsc.202200629
日期:2022.9.6
developed has broad substrate scope and is amenable to gram-scale synthesis. The method gives ready access to even hexa-substituted cyclic ethers containing two quaternary carbons. This strategy is used in the construction of oxaspirocyclic systems. Diastereoselective synthesis of fused bicyclic as well as tricyclic motifs could be achieved. The stereochemistry of the products was assigned using NOE experiments
描述了一种立体选择性合成取代四氢呋喃 (THFs)、四氢吡喃 (THPs) 以及色满的方法,该方法使用分子间氢原子转移 (HAT),然后对烯基乙烯基碳酸酯进行分子内自由基环化。该 Fe(acac) 3催化反应使用 PhSiH 3作为 H 源,在环境条件下以 HFIP/乙二醇(5:1 混合物)作为溶剂工作。开发的方法具有广泛的底物范围,适合克级合成。该方法甚至可以很容易地获得含有两个季碳的六取代环醚。该策略用于构建氧杂螺环系统。可以实现稠合双环和三环基序的非对映选择性合成。使用 NOE 实验确定产物的立体化学,并通过对两种衍生物的单晶 X 射线衍射研究进一步证实。