| Due to fossil fuel combustion and industrial production,the concentration of carbon dioxide（CO2）in the aerosphere has been continuously increasing since the industrial revolution,which has caused a series of significant climate problems such as global warming.CO2 is recognized to be the most abundant C1 resource in nature,which possesse the advantages of nonflammability,economy,nontoxicity and renewability.The development of efficient strategies for the capture and transformation of CO2 into value-added products under mild conditions fulfills the principles of sustainable development and the requirements of carbon-neutral strategy.Organic carbamates have been widely used in areas of agricultural chemicals,resin modification and fabric finishing.Besides,they are also key intermediates in the synthesis of fine chemicals and pharmaceuticals compounds.α-hydroxy ketones are an important class of multifunctional and bioactive compounds,which have significant value in the synthesis of organic chemicals as well as in,biological and chemical industrial fields.Based on this,this thesis focuses on the design and synthesis of high-performance catalytic systems for CO2 conversion and utilization for the synthesis of carbamates andα-hydroxy ketones,which could be divided into the following two parts.（1）In this thesis,a catalytic system based on zinc oxide/1-ethyl-3-methylimidazolium acetate（Zn O/[C2C1im][OAc]）was developed for the three-component coupling reaction of secondary amines,propargylic alcohols,and CO2 to synthesizeβ-oxopropylcarbamates under atmospheric pressure.Besides,the methodology avoided the usage of any additional organic strong bases or ligands,and exhibited broad substrate scope and high functional group tolerance.it could be effectively recycled.It is worth noting that this catalytic system also showed high catalytic activity in the simulated flue gas atmosphere and gram-scale reaction,indicating its practicability and versatility for the carbon capture and utilization process.（2）An unexpected CO2-induced rapid dissolution of Zn O in ionic liquids was first discovered in the experiment.Then,the dissolved mixture was applied for the reaction of CO2-promoted hydration of propargylic alcohols under atmospheric pressure,which showed outstanding catalytic activity.Based on the results in Chapter2 of this thesis,the substrate scope of this reaction was investigated in simulated flue gas atmosphere,which can successfully convert various terminal or internal tertiary propargylic alcohols and secondary propargylic alcohol into the correspondingα-hydroxyl ketones with excellent yields.Notably,the pure Zn O sources in the system can be replaced by waste pigments to catalyze the target reaction,providing a novel integrated method for the treatment and utilization of waste Zn O and flue gas.Further mechanistic investigations revealed that the interaction between Zn O,CO2 and ionic liquids to generate the N-heterocyclic carbenes CO2 adducts is the key factor to accelerate the dissolution.These adducts were further identified to exhibit better reactivity and lower energy barrier than the normal CO2 by control experiments and density functional theory calculations,which might be responsible for the excellent performance of the Zn-based catalytic system. |
