An electrooxidative [3 + 2] annulation of phenols and electron-deficient alkenes for the synthesis of C3-functionalized 2-aryl-2,3-dihydrobenzofuran derivatives was achieved. The ring construction starts by a unique α-addition of carbon radicals derived from anodic oxidation of phenols to electron-deficient alkenes. The subsequent anodic oxidation of the resulting alkyl radical intermediates followed by trapping with the phenolic hydroxy group assembles the 2,3-dihydrobenzofuran core. Such a pathway enables the installation of various electrophilic functionalities including alkoxycarbonyl, alkylaminocarbonyl, trifluoromethyl, and cyano groups at the C-3 of the 2,3-dihydrobenzofuran framework, which is unattainable by other intermolecular reactions. The application of this method for a rapid synthesis of a bioactive natural product is demonstrated.

中文翻译：

---

自由基α加成涉及酚和缺电子烯烃的电氧化[3 + 2]环化

实现了苯酚和缺电子烯烃的电氧化[3 + 2]环合反应，用于合成C3官能化的2-芳基-2,3-二氢苯并呋喃衍生物。环的构建始于独特的α加成，该加成源自酚的阳极氧化成电子不足的烯烃的碳自由基。所得烷基中间体的随后阳极氧化，然后用酚羟基捕获，从而组装了2，3-二氢苯并呋喃核。这种途径使得能够在2，3-二氢苯并呋喃骨架的C-3上安装各种亲电子官能团，包括烷氧基羰基，烷基氨基羰基，三氟甲基和氰基，这是其他分子间反应无法实现的。证明了该方法在生物活性天然产物的快速合成中的应用。