Unified Approach to Fused and Spirocyclic Oxindoles through Lewis‐Acid‐Promoted Opening of Spiroepoxyoxindoles with Allylsilanes: Application to the Formal Synthesis of (±)‐Physovenine

Abstract

A protocol for the construction of oxindoles containing all‐carbon quaternary centres in a highly regioselective manner has been developed. The reaction involves opening of spiroepoxyoxindoles with allylsilanes to give Hosomi–Sakurai‐type products as well as new silicon‐containing spirocyclic oxindoles. A formal synthesis of (±)‐physovenine was accomplished in five steps using this protocol.