Non-precious Metal Catalysts And Organocatalysts For Allylic Alkylation And Cascade Reactions

Due to increasing presure from environment and the awareness of theenvironment protection, non-precious metal catalysis and organocatalysis arebecoming a hot area. In this dissertation, the electron and steric properties ofligand are tuned to obtain novel iron catalysts that are used to catalyze theregioselective allylic alkylation. Some novel cascade reactions are developedthrough employing non-precious metal catalysts or organocatalyst or evenboth. More importantly, all the developed reactions are to prepare biologicallyactive molecules. The main innovative findings and conclusions are listed:1. A simple, inexpensive and efficient diamine was developed for Fe(-II)catalyzed regioselective allylic alkylation and excellent yields (up to94%) andgood regioselectivity (up to>20:1) were obtained. A novel diimine ligandFe(-II) catalyst was developed to catalyze regioselective allylic alkylation ofoxindole with broad substrate scope, high yield (up to90%) and goodregioselectivity (up to>20:1).2. Cu(II) salt catalyzed oxidation-[3+2] cycloaddition-aromatization cascade reaction was developed to efficiently prepare biologically importantpyrrolo [2,1-a] isoquinolines. In this methodology, highly active azomethinesyield was formed through in-situ oxidization of stable amine, avoiding theinconvenience caused by synthesis and storage of unstable azomethines yield.3. An amine thiourea bifunctional organocatalyst catalyzed cascadethio-Michael-Michael reaction was developed to form biologically significanttrisubstituted tetrahydrothiophenes with up to97%enantioselectivity and up to>30:1diastereoselectivity. An unprecedented activation mode of cooperativedirect stereocontrol and dynamic kinetic resolution explains the excellentstereocontrolling ability obtained in this challenging reaction.4. The novel dual cooperative asymmetric aminocatalysis and Lewis acidcatalysis was successfully developed for promoting cascadeMichael-cyclization reaction with high enantio-, regio-and chemo-selectivity.The simple and practical process affords a one-pot approach to syntheticallyuseful cyclopentenes. The interaction between lewis acid catalysts andaminocatalyst are carefully tuned through altering the lewis acid catalysts,avoiding the lose of catalytic activity or stereocontrolling ability. The noveldual catalysis extended the scope of traditional catalysis and provided afoundation for further research.