Ring Transformation of Cyclopropenes to Benzo‐Fused Five‐Membered Oxa‐ and Aza‐Heterocycles via a Formal [4+1] Cyclization

• DOI: 10.1002/advs.202407931
• Publication Date: 2024-08-29T10:34:18Z
• Authors: Fengyan Gu; Binyan Lin; Zhi‐Huan Peng; Shijie Liu; Yuanqing Wu; Mei Luo; Ning Ding; Qichen Zhan; Peng Cao; Zhi Zhou; Tao Cao
• Keywords: heterocycles; late‐stage modifications; ring transformation; Science; cyclopropenes; rhodium; Q; DFT calculations; Research Article; 0104 chemical sciences

Abstract In the context of growing importance heterocyclic compounds across various disciplines, numerous strategies for their construction have emerged. Exploiting distinctive properties cyclopropenes, this study introduces an innovative approach synthesis benzo‐fused five‐membered oxa‐ and aza‐heterocycles through a formal [4+1] cyclization subsequent acid‐catalyzed intramolecular O ‐ to N rearrangement. These transformations exhibit mild reaction conditions wide substrate scope. The applications in late‐stage modification complex molecules potential PD‐L1 gene down‐regulator, make method highly appealing related fields. Combined experimental mechanistic studies DFT calculations demonstrate Rh(III)‐mediated sequential C─H coupling/π‐allylation/dynamically favorable ‐attack route.