Efficient Assembly of Molecular Complexity Enabled by Palladium‐Catalyzed Heck Coupling/C(<i>sp</i><sup>2</sup>)−H Activation/ C(<i>sp</i><sup>3</sup>)−H Activation Cascade
Chen He, Wen‐Yong Han, Bao‐Dong Cui, Nan‐Wei Wan, Yong‐Zheng Chen
Abstract
Abstract A palladium‐catalyzed [2+2+1] annulation among 3‐iodochromones, benzyl bromides, and norbornene has been developed. This annulation consists of a domino sequence involving Heck coupling/C( sp 2 )−H activation/C( sp 3 )−H activation, affording a variety of complex chromone derivatives bearing five contiguous tertiary carbon centers in up to 94% yield and 99:1 dr. Interestingly, the diastereoselectivity could be switched by fine‐tuning the solvent, in which endo isomer and exo isomer were obtained using mesitylene/CH 3 CN and mesitylene, respectively. magnified image
Topics & Concepts
ChemistryMesitylenePalladiumAnnulationHeck reactionCatalysisNorborneneStereochemistryYield (engineering)Medicinal chemistryOrganic chemistryPolymerMonomerMaterials scienceMetallurgyCatalytic C–H Functionalization MethodsSynthesis of Organic CompoundsOxidative Organic Chemistry Reactions