Kinetic Resolution Approach to the Synthesis of C–N Axially Chiral<i>N</i>-Aryl Aminomaleimides via NHC-Catalyzed [3 + 3] Annulation
Soumen Barik, Rohan Chandra Das, Kuruva Balanna, Akkattu T. Biju
Abstract
Chiral NHC-catalyzed kinetic resolution of N-aryl aminomaleimides allowing the synthesis of C–N axially chiral N-aryl aminomaleimides via remote chirality control is presented. The catalytically generated α,β-unsaturated acylazoliums from 2-bromoenals underwent selective [3 + 3] annulation with one of the enantiomers of maleimide to furnish fused-dihydropyridinone (bearing axial/central chirality, up to 6:1 dr, >99:1 er) leaving the enantioenriched opposite enantiomer (up to >99:1 er). Studies on C–N bond rotation barrier and dependence on temperature are also provided.
Topics & Concepts
AnnulationChemistryKinetic resolutionAxial chiralityArylEnantiomerChirality (physics)Axial symmetryCatalysisAtropisomerStereochemistryMaleimideKinetic energyEnantioselective synthesisOrganic chemistryPhysicsChiral symmetry breakingNambu–Jona-Lasinio modelQuarkQuantum mechanicsAlkylN-Heterocyclic Carbenes in Organic and Inorganic ChemistryAxial and Atropisomeric Chirality SynthesisCatalytic Cross-Coupling Reactions