Studies On The Allylation Of 2-Aryl-3H-indol-3-ones

Indolin-3-ones with a chiral center at the C2 position are widely distributed in a series of natural products and drug molecules.On the other hand,homoallylamine is a core structural unit widely present in natural products and pharmaceuticals molecules.Under the catalysis of chiral thiourea,squaramide and other double hydrogen bonding catalysts and chiral phosphoric acid（CPA）,the amination,thiolation,and difluoroalkylation of indolin-3-one have been achieved,while the research on the asymmetric allylation of indolin-3-one is still in a blank.2-Allyl-indolin-3-ones,as synthetic intermediates,are transformed into many important compounds due to their easily derivatized terminal olefins.In this thesis,the following researches have been carried out around the asymmetric allylation of 2-phenyl-3H-indolinones:（1）Catalytic enantioselective ketimine-ene reactions of 2-aryl-3H-indol-3-ones α-methylstyrenes are achieved by utilizing a B（C₆F₅）₃/chiral phosphoric acid （CPA）complex catalyst.These ketimine-ene reactions proceed well with low catalyst loading（B（C₆F₅）₃/CPA=2 mol%/2 mol%）under mild conditions,providing a rapid and facile access to a series of functionalized 2-allyl-indolin-3-ones with very good reactivities（up to 99%yield）and excellent enantioselectivities（up to 99%ee）.Theoretical calculations are carried out to elucidate the activity and stereoselectivity differences between CPA and B（C₆F₅）₃/CPA,in which B（C₆F₅）₃ not only improves the acidity of phosphoric acid,but also helps stabilize the transition state and change the chiral control environment by the C–H···F hydrogen bonding interaction.Meanwhile,the enhanced N–H···O hydrogen bonding as well as the C–H···F hydrogen bonding may be important factors for the stereo-control of the B（C₆F₅）₃/CPA catalyzed ketimine-ene reactions.（2）N-Bpin-2-allyl-2-aryl-3H-indolinones were constructed using 2-aryl-3H-indolinones and allylboronic acid pinacol esters as substrates.Substrates bearing electron-donating,electron-withdrawing and halogen groups were tolerable in this reaction（up to 99%yield）.Meanwhile,the existence of N–B bond provides the possibility for further transformation of the products.