Bifunctional Borane Catalysis of a Hydride Transfer/Enantioselective [2+2] Cycloaddition Cascade
Ming Zhang, Xiaochen Wang
Abstract
Herein, we present a mild and efficient method for synthesizing enantioenriched tetrahydroquinoline-fused cyclobutenes through a cascade reaction between 1,2-dihydroquinolines and alkynones with catalysis by chiral spiro-bicyclic bisboranes. The bisboranes served two functions: first they catalyzed a hydride transfer to convert the 1,2-dihydroquinoline substrate to a 1,4-dihydroquinoline, and then they activated the alkynone substrate for an enantioselective [2+2] cycloaddition reaction with the 1,4-dihydroquinoline generated in situ.
Topics & Concepts
Enantioselective synthesisBifunctionalCycloadditionHydrideCatalysisChemistrySubstrate (aquarium)BoraneCombinatorial chemistryTransfer hydrogenationCascadeOrganocatalysisOrganic chemistryHydrogenRutheniumChromatographyOceanographyGeologyOrganoboron and organosilicon chemistryChemical Synthesis and AnalysisAsymmetric Hydrogenation and Catalysis