Organocatalytic Enantioselective Synthesis of Chiral Allenes: Remote Asymmetric 1,8‐Addition of Indole Imine Methides
Xingguang Li, Jianwei Sun
Abstract
An organocatalytic enantioconvergent synthesis of chiral tetrasubstituted allenes is disclosed. With suitable chiral phosphoric acid catalysts, a range of racemic indole-substituted propargylic alcohols reacted with nucleophiles to provide efficient access to a series of enantioenriched allenes with high enantioselectivities. Control experiments suggested a mechanism involving remotely controlled asymmetric 1,8-addition of the in situ generated indole imine methide via a bifunctional transition state.
Topics & Concepts
Enantioselective synthesisChemistryImineBifunctionalIndole testNucleophileOrganocatalysisPhosphoric acidOrganic chemistryCombinatorial chemistryCatalysisSynthesis of Indole DerivativesAxial and Atropisomeric Chirality SynthesisCatalytic C–H Functionalization Methods