Palladium-catalyzed Asymmetric[3+2] Cycloaddition Reaction Of Vinyl Cyclopropanes And Isatin Derived Imines

Spiro-oxindole derivatives especially the spiro-cyclopentane oxindoles play a key role in numerous alkloids and pharmaceuticals and exhibit important biological and pharmacological activities. The efficient and rapid aceess to the spiro cyclopentene oxindoles received great attentions over the past years. The widely employed approach to the target molecules concerns the enantioselective cycloadditions of azomethine ylides and electron deficient olefins. The spiro-oxindole derivative can also be achieved by tandem or domino reaction through multi-step transformations. In the thesis, we have developed a chiral palladium complex catalyzed asymmetric and diastereoselective [3+2] cycloaddition of vinyl cyclopropanes and isatin derived imines.The protocol involes the formation of chiral ampilic allylic palladium complex as well as the enantioselective cycloaddition of isatin derived imines and the transient formed palladium complex. The reaction is substrate tolerable affording the enantiomerically and structurally enriched spiro-oxindoles in high yields(up to 96% yield) and with excellent enantioselectivities(96% ee) and good diatereoselectivities(up to 5:1). All products were identified by 1H NMR, 13 C NMR, HRMS.