Copper-catalyzed Asymmetric Silyl Addition To Alkenyl-substituted N-heteroarenes

N-Containing heteroarenes are very important structural units,which are commonly found in a wide variety of natural products and pharmaceutically active compounds.Although elaboration of the N-containing heteroarenes continues to be the main approach to access functionalized heterocyclic aromatic compounds,exploration of asymmetric conjugate addition of nucleophiles to alkenes activated by adjacent N-containing heteroarenes has gained prominence in the last decade.Among them,nucleophiles mainly include carbon,nitrogen,oxygen,boron,and sulfur reagents.However,the study of using silicon as a nucleophile has not been reported.Chiral silanes are versatile intermediates in organic synthesis.The silicon motif is widely used as a masked hydroxyl group,and the C-Si bond can also be readily transformed into C-C bonds.Thus,further development of catalytic highly enantioselective silyl addition to alkenes activated by N-containing heteroarenes is urgently demanded.We selected 2-alkenylquinoline and Ph Me₂Si Bpin as model substrates.Through the screening of chiral ligands,reaction solvents,catalysts,reaction temperature,additives（alcohols,bases）,the optimal conditions are obtained.A series of usefulβ-silyl N-heteroarenes were achieved in high yields and ees.Moreover,the reaction can be effectively performed at room temperature on a gram scale.Finally,the addition products were characterized by ¹H-NMR,¹³C-NMR,high-resolution mass spectrometry,high-performance liquid chromatography,and the absolute configuration of product 37i was determined by X-ray single crystal diffraction.