Highly stereoselective construction of polycyclic benzofused tropane scaffolds and their latent bioactivities: bifunctional phosphonium salt-enabled cyclodearomatization process

• 作者: Chunhui Jiang Jian-Ping Tan Kai Xiao Lixiang Zhu Tianli Wang Xianle Rong Xiaojie Li Yuan Chen
• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2020,（8）
• 所属期刊栏目: ARTICLES
• 页码范围: 1091-1099
• 页数: 9页
• 语种: 英文

摘要

Structurally fused heterocycles encompassing a centerpiece of benzotropane are significant scaffolds with a plethora of promising biological activities,but such molecular architectures pose a long-standing daunting synthetic challenge.Herein,we reported a highly efficient asymmetric cyclodearomatization of 2-nitrobenzofurans with cyclic azomethine ylides by employing bifunctional phosphonium salts as phase-transfer catalysts.Under optimized reaction conditions,a diverse array of polycyclic benzofused tropane derivatives with four contiguous 4°/3° stereocenters were readily synthesized in both high yields and diastereoselectivities with up to ＞99％ ee.The practicality and utility of this protocol were further demonstrated by the scaled-up reaction and facile elaborations.Moreover,preliminary investigations into their antitumor activities were also presented.