Titanium‐Mediated Synthesis of Spirocyclic NH‐Azetidines from Oxime Ethers

Abstract

AbstractThe TiIV‐mediated synthesis of spirocyclic NH‐azetidines from oxime ethers using either an alkyl Grignard reagent or terminal olefin ligand exchange coupling partner is described. Through a proposed Kulinkovich‐type mechanism, a titanacyclopropane intermediate forms and serves as a 1,2‐aliphatic dianion equivalent, inserting into the 1,2‐dielectrophilc oxime ether to ultimately give rise to the desired N‐heterocyclic four‐membered ring. This transformation proceeds in moderate yield to furnish previously unreported and structurally diverse NH‐azetidines in a single step.