Iridium-Catalyzed Diastereo- and Enantioselective [4 + 3] Cycloaddition of 4-Indolyl Allylic Alcohols with Azomethine Ylides
Wu‐Lin Yang, Tao Ni, Wei‐Ping Deng
Abstract
An unprecedented iridium-catalyzed asymmetric [4 + 3] cycloaddition of racemic 4-indolyl allylic alcohols with azomethine ylides is reported. The ability of acid promoter zinc triflate to perform multiple roles is the key factor for the success of this strategy. This method provides scalable and efficient access to biologically important azepino[3,4,5-cd] indoles in good yields with generally excellent diastereo- and enantioselectivities (up to >20:1 dr and >99% ee). Mild reaction conditions, easily accessible substrates and chiral catalyst, and broad substrate scope highlight the practicality of this methodology.
Topics & Concepts
ChemistryAllylic rearrangementCycloadditionCatalysisEnantioselective synthesisIridiumTrifluoromethanesulfonateCombinatorial chemistrySubstrate (aquarium)ZincOrganic chemistryGeologyOceanographyCatalytic C–H Functionalization MethodsAsymmetric Hydrogenation and CatalysisAsymmetric Synthesis and Catalysis