Asymmetric (4 + 3) and (4 + 1) Annulations of Isatin-derived Morita–Baylis–Hillman Carbonates to Construct Diverse Chiral Heterocyclic Frameworks
Ru‐Jie Yan, Bao-Xin Liu, Ben‐Xian Xiao, Wei Du, Ying‐Chun Chen
Abstract
A chiral tertiary amine-catalyzed asymmetric γ-regioselective (4 + 3) annulation reaction of isatin-derived Morita–Baylis–Hillman carbonates and 1-azadienes was developed, delivering chiral azepane spirooxindoles with excellent stereoselectivity. In addition, by tuning the substituents of Morita–Baylis–Hillman carbonates, the switchable γ-(4 + 3) or α-(4 + 1) annulation reaction with o-quinone methides was observed to furnish benzo[b]oxepines or 2,3-dihydrobenzofurans, respectively, under similar catalytic conditions.
Topics & Concepts
IsatinAnnulationChemistryRegioselectivityBaylis–Hillman reactionStereoselectivityOrganocatalysisCatalysisAmine gas treatingOrganic chemistryStereochemistryEnantioselective synthesisCombinatorial chemistryAsymmetric Synthesis and CatalysisCatalytic C–H Functionalization MethodsSynthesis of Indole Derivatives