Sc(OTf)3-Catalyzed Ring-Opening Reactions of Donor-Acceptor Cyclopropanes/Bicyclo[1.1.0]butanes: Access to 3-Substituted Chromenones, Cyclopenta[b]chromenones and 2-Aminobicyclo[2.1.1]hexanes

Abstract

A robust Sc(OTf)3-catalyzed and DBN-assisted strain-release-driven ring-opening-annulation reaction of ortho-hydroxyarylenaminones with an array of 2-aryl-substituted cyclopropane 1,1-diesters as perfect 3 C atoms reactive synthons to create three new C−C, C−O, and C−C bonds sequentially is reported. This one-pot two-step process concocts various value-added poly-substituted tetrahydrocyclopenta[b]chromenones in reasonable yields with excellent diastereoselectivities. Pleasantly, this newly developed Lewis acid-catalyzed technique also facilitates the strain-release driven ring-opening reactions involving highly strained bicyclo[1.1.0]butanes as enamine acceptors, endowing the quick access to synthetically challenging 2-aminobicyclo[2.1.1]hexanes and α-cyclobutyl-β-arylacrylaldehydes with excellent diastereoselectivities. © 2025 Wiley-VCH GmbH.