Studies On The Oxidative Dehydrogenation Of Ketones Via Enantioselective Desymmetrization

The conversion of ketones to the more versatile enone functionality is an important transformation in organic synthesis due to the utility of enones as intermediates in multistep production of pharmaceuticals and natural products.Although this kind of methods have been reported widely in known references,the desymmetrizing dehydrogenation of structurally symmetric ketones hasn't been established comprehensively.This dissertation is mainly about the investigations of this reaction by utilizing Pd^II catalyst and corresponding chiral ligands.The related content will be unfolded from the following three chapters:Part ?:The introduction of the methods that obtain the alkene unit adjacent to a keto group from the ketones,which are well-precedented in the literature and can be broadly categorized into two main areas:two-step methods that proceed via?-functionalized ketone intermediates and one-step methods that directly access enones from ketones in a single operation.Part ?:Inspired by known references,we have investigated the reactivity of the model substrate and carried out the racemic transformation.After that,the enantioselective desymmetrizing dehydrogenation of model substrate based on Imidization-Coordination Model was incipiently studied.Part ?:We preliminarily achieved the enantioselective desymmetrizing dehydrogenation of the model substrate under the catalysis of palladium trifluoroacetate and pyridine-oxazoline ligands.Meanwhile,the substrate scope and limitations of the current reaction as well as the subsequent tandem Michael addition have been explored,laying down a foundation for the further research on asymmetric desymmetrizing dehydrogenation reaction of ketones.