Palladium-mediated domino oxidative amination of cyclohexadienes as an entry to indole alkaloids

Abstract A palladium-mediated double oxidative amination reaction on cyclohexa-2,5-dienes has been developed, leading to the tetracyclic indoline skeleton of aspidosperma and strychnos alkaloids. The allyl-palladium intermediate, generated after the double oxidative amination, could be trapped by an internal nucleophile to allow the construction of 3 rings in a single step. Approaches to the synthesis of strychnine and mossambine is finally reported.