Gold‐Catalyzed Orthogonal and Chemocontrolled Synthesis of [4‐7‐6] Tricycles from 1,5‐Diynes

Abstract

We report a one‐pot cascade sequence catalyzed by gold starting from 1,5‐diynes and a zwitterion (source of Tf2C=CH2), which allows the chemo‐, regio‐ and stereoselective preparation of cyclobutene‐fused [4‐7‐6] tricycles and displays orthogonal reactivity of the 1,5‐diyne system, zwitterion and metal catalyst. Moreover, the obtained tricyclic bis(triflyl)cyclobutenes [triflyl = (trifluoromethyl)sulfonyl] can be easily converted into more complex structures such as bridged ketal and fused 1,3‐oxazine tetracyclic systems, demonstrating the potential of our protocol.