Main Group-Catalyzed Cationic Claisen Rearrangements via Vinyl Carbocations

Abstract

We report a catalytic C−O coupling/Claisen cascade reaction enabled by interception of vinyl carbocations with allyl ethers. The reaction utilizes commercially available borate salts as catalysts and is effective at constructing sterically hindered C−C bonds. The reaction mechanism is studied experimentally and computationally to support a charge-accelerated [3,3] rearrangement of a silyloxonium cation. Our reaction is also applied to the highly stereoselective synthesis of fully substituted vinyl ethers.