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.

围绕苯并烷的中心结构稠合杂环是重要的支架，具有大量有前途的生物活性，但是这种分子结构对合成提出了长期的艰巨挑战。在本文中，我们报道了通过使用双官能salts盐作为相转移催化剂，用环偶氮甲亚胺将2-硝基苯并呋喃进行高效不对称环脱芳香化反应。在优化的反应条件下，可以容易地以高收率和非对映选择性（最高> 99％ee）合成具有四个连续的4°/ 3°立体中心的各种多环苯并稠合的托烷衍生物。该方案的实用性和实用性通过规模扩大的反应和简便的阐述得到了进一步证明。此外，