Organocatalytic cycloaddition–elimination cascade for atroposelective construction of heterobiaryls
Wenlei Xu, Weiming Zhao, Ruxia Zhang, Jie Chen, Ling Zhou
Abstract
The first chiral phosphoric acid (CPA) catalyzed cycloaddition-elimination cascade reaction of 2-naphthol- and phenol-derived enecarbamates with azonaphthalenes has been established, providing a highly atroposelective route to an array of axially chiral aryl-C3-benzoindoles in excellent yields with excellent enantioselectivities. The success of this strategy derives from the stepwise process involving CPA-catalyzed asymmetric formal [3 + 2] cycloaddition and subsequent central-to-axial chirality conversion by elimination of a carbamate. In addition, the practicality of this reaction had been verified by varieties of transformations towards functionalized atropisomers.
Topics & Concepts
AtropisomerCycloadditionChemistryAxial chiralityCombinatorial chemistryCascadeArylPhosphoric acidCatalysisYield (engineering)PhenolOrganic chemistryEnantioselective synthesisMaterials scienceMetallurgyAlkylChromatographyAxial and Atropisomeric Chirality SynthesisMolecular spectroscopy and chiralityAlkaloids: synthesis and pharmacology