Catalytic Asymmetric Dearomatization of 2,3-Disubstituted Indoles by a [4 + 2] Cycloaddition Reaction with In Situ Generated Vinylidene <i>ortho</i>-Quinone Methides: Access to Polycyclic Fused Indolines
Amit Shikari, Chandrakanta Parida, Subhas Chandra Pan
Abstract
A protocol of enantioselective dearomatization of 2,3-disubstituted indoles by an organocatalytic intermolecular (4 + 2) cycloaddition reaction with in situ generated vinylidene ortho -quinone methide has been documented. A wide range of polycyclic 2,3-fused indolines containing vicinal quaternary carbon stereocenters was readily prepared in high yields and with excellent diastereo- and enantioselectivities.
Topics & Concepts
StereocenterChemistryCycloadditionEnantioselective synthesisCatalysisVicinalIntermolecular forceQuinoneIn situCombinatorial chemistryOrganic chemistryMedicinal chemistryMoleculeSynthesis of Indole DerivativesAxial and Atropisomeric Chirality SynthesisAsymmetric Synthesis and Catalysis