Synthesis of Fused Dibenzofuran Derivatives via Palladium-Catalyzed Domino C–C Bond Formation and Iron-Catalyzed Cycloisomerization/Aromatization
作者:Kartick Paul、Swapnadeep Jalal、Sandip Kundal、Umasish Jana
DOI:10.1021/acs.joc.5b02637
日期:2016.2.5
A range of tetracyclic dibenzofuran derivatives bearing a variety of functional groups was readily synthesized via a two-stage domino strategy starting from propargyl ethers of 2-halo phenol derivatives. The first stage in the strategy involves Pd(0)-catalyzed domino intramolecular carbopalladation/Suzuki coupling via 5-exo-dig cyclization onto the alkyne, leading to 3-methylene-2,3-dihydrobenzofuran
容易地通过两阶段的多米诺骨牌策略从2-卤代苯酚衍生物的炔丙基醚开始合成一系列带有各种官能团的四环二苯并呋喃衍生物。该策略的第一阶段涉及通过5- exo - dig的Pd(0)催化的多米诺骨牌分子内碳糖蛋白/铃木偶联环化到炔烃上,得到3-亚甲基-2,3-二氢苯并呋喃衍生物。在多米诺骨牌策略的第二阶段,铁(III)催化的环异构化和芳构化反应生成四环苯并呋喃衍生物。该两步序列提供了以高收率和原子有效且环境友好的方式有效地获得各种取代的多环二苯并呋喃衍生物的途径。此外,该策略也已成功用于合成天然存在的四环二苯并呋喃,β-brazan。