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Synthesis of spirooxindoles via formal acetylene insertion into a common palladacycle intermediate† † Electronic supplementary information (ESI) available. CCDC 2244743 and 2244744. For ESI and crystallographic data in CIF or other electronic format see DOI: https://doi.org/10.1039/d3sc01072d

ABSTRACT: A palladium-catalyzed spirocyclization reaction is reported, which is proposed to arise via insertion of an oxabicycle into a palladacycle, formed from carbocyclization and a C–H functionalization sequence. Mechanistic studies suggest the insertion is diastereoselective and a post-catalytic retro-Diels–Alder step furnishes an alkene, wherein the oxibicycle has served as an acetylene surrogate. Aryl iodides and carbamoyl chlorides were compatible as starting materials under the same reaction conditions, enabling the convergent and complementary synthesis of spirooxindoles, as well as other azacycles. These spirooxindoles allowed further transformations that were previously unaccessible. A palladium-catalyzed spirocyclization reaction is reported and proposed to arise via diastereoselective insertion of an oxabicycle into a palladacycle. The cycloadduct undergoes a post-catalytic retro-Diels–Alder step to furnish a previously inaccessible cis-alkene.

SUBMITTER: Abel-Snape X

PROVIDER: S-EPMC10231318 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature

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