Key Laboratory of Medicinal Chemistry for Natural Resources, Ministry of Education and Yunnan Province, State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, P. R. China.
Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA, USA.
Angew Chem Int Ed Engl. 2019 Feb 25;58(9):2826-2830. doi: 10.1002/anie.201812369. Epub 2019 Jan 29.
Benzofurans are among the most popular structural units in bioactive natural products, however, the synthesis of such structures by radical cyclization cascade reactions is rare. Herein, we report a mild and broadly applicable method for the construction of complex benzofurylethylamine derivatives through a unique radical cyclization cascade mechanism. Single-electron transfer (SET) from 2-azaallyl anions to 2-iodo aryl allenyl ethers initiates a radical cyclization that is followed by intermolecular radical-radical coupling. This expedient approach enables the synthesis of a range of polycyclic benzofurans that would otherwise be difficult to prepare.
苯并呋喃是生物活性天然产物中最受欢迎的结构单元之一，然而，通过自由基环化级联反应合成此类结构的方法很少。在此，我们报道了一种温和且广泛适用的方法，通过独特的自由基环化级联机制构建复杂的苯并呋喃乙胺衍生物。2-氮杂烯丙基阴离子向 2-碘芳基烯丙基醚的单电子转移（SET）引发自由基环化，随后是分子间自由基-自由基偶联。这种简便的方法能够合成一系列多环苯并呋喃，否则这些多环苯并呋喃很难制备。
