AlCl3-Promoted Selective Michael Addition with Allenoate and Methyleneindolinone: Synthesis of Spirocyclic Oxindole by Using Allenoate as a Four-Carbon Component Building Block

摘要: The AlCl3-promoted cyclization of readily available allenoates with methyleneindolinone is disclosed. present strategy provides a rapid access to spirocyclic oxindole-cyclohexenones in an efficient manner. Remarkably, the allenoate implemented as four-carbon (4C) component form ring, which shows high synthetic efficiency. Flexibility this method allows quick synthesis oxindole-dihydropyrans by varying one components. It also noteworthy that AlCl3 serves chlorine source well effective catalyst facilitate interesting transformation.