Asymmetric (4 + 3) and (4 + 1) Annulations of Isatin-derived Morita-Baylis-Hillman Carbonates to Construct Diverse Chiral Heterocyclic Frameworks

Org Lett. 2020 Jun 5;22(11):4240-4244. doi: 10.1021/acs.orglett.0c01283. Epub 2020 May 15.

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.

Publication types

  • Research Support, Non-U.S. Gov't