DOI: 10.1002/ajoc.70548 ISSN: 2193-5807
Gold (I)‐Catalyzed (4 + 2) Annulation of 1‐(1‐Alkynyl)Cyclopropyl Ketones With 1,3,5‐Triazinanes: Synthesis of Piperidine‐Fused Furans
Songyi Gao, Yue He, Mengnan Liu, Mengjia Zhu, Yidan Zhao, Ming Lang, Huan Jin, Shiyong PengABSTRACT
A gold(I)‐catalyzed chemoselective (4 + 2) annulation of 1‐(1‐alkynyl)cyclopropyl (ACP) ketones with 1,3,5‐triazinanes is developed, affording a series of piperidine‐fused furans in moderate‐to‐excellent yields. Chirality‐transfer experiments support an S N 2‐type mechanism involving a cyclopropyloxonium‐containing vinyl‐gold intermediate ( Int‐II ), enabling access to enantioenriched piperidine‐fused furans. The utility of this protocol is further demonstrated by scale‐up reactions and the extension to ACP oximes for the construction of piperidine‐fused pyrroles.