Studies On The Nucleophilic Addition/Oxidativecyclization Of α-oxo Ketene Dithioacetals And Aliphatic Aldehydes

a-Oxo ketene dithioacetalsis a kind of important intermediates in organic synthesis, which bears multiple reaction sites. In recent decades, the applications of ketene dithioacetals have been developed rapidly especially in the formation of various carbon/hetero-cycles. Our group has long been engaged in ketene dithioacetal chemistry. We have obtained a series of achievements in terms of a-functionalization reactions, cyclization reactions, multi-component reactions etc. However, the oxidation reaction of a-oxo ketene dithioacetals are still limiteduntil now.The oxidation reaction is an important class of organic reactions. In recent years, great progress has been made in transition metal-catalyzed oxidationreaction. However, the catalysts used in these reactions are often expensive noble metals such as Pd, Au, Ag etc. The oxidants such as BQ, AgO₂, PhI（OAc）₂ etc, often cause the environmental problems. Nowadays,with the requirements towards green chemistry, how to find efficient, green chemical reagents and synthetic routes has become a hot research topic. Therefore, copper catalyst systems have been focused to build a variety of carbon-carbon bonds and carbon-heteroatom bond because they are cheap, easily available and environmental friendly.At the same time, reducing the reaction step is also very important. Tandem reaction generally refers to the intermediate generated from the first stepof the reactioncan be used directly in the second and third step without further separation and purification, such as tandem addition reaction, tandem cyclization reaction etc. Currently, tandem reactions have been successfully applied to the synthesis of heterocyclic compounds and asymmetric syntheses, in particular with the synthesis of optically active natural products and the complex molecules.Based on our previous works,in this thesis, a series of naphthalenoneshave been obtained from simple and accessible a-Oxo ketene dithioacetals involved by CuBr₂undergoing the tandem nucleophilic addition/oxidative cyclization reaction. The structures of the products have been verified by NMR spectra, high-resolution mass spectra. Meanwhile, the mechanism of this reaction has been discussed in details.