Study On Catalytic Selective Reaction Of Intelligent Microreactor Based On Emulsion System

Microemulsion or micelle is one of the main methods to solve the problem of catalyst and substrate immiscibility.The concept of"compartmentalization"of emulsion is mainly applied.Due to the function of compartment,the immiscible substrate and biocatalytic substance are separated in space,which can avoid unwanted interference between multiple substances.This method can effectively increase the contact area between the substrate and the catalyst,increase the reaction sites,and thus effectively improve the reaction efficiency.And the type of emulsion has an important impact on the distribution of species,thus affecting the catalytic effect.However,little research has been done on the position distribution of species in the phase during the reaction process,which is also the biggest problem and challenge faced by emulsion catalysis in recent years.On this basis,we propose a new strategy for catalytic selective reaction of emulsion intelligent microreactor,which selects aniline and the synthesis of nitrogen heterocyclic compounds byα-ketone ester/acid reaction is used as a model reaction to build an intelligent microreactor using the liquid-liquid phase state of the emulsion.The emulsion droplets can be used to encapsulate and control some insoluble catalysts and substrates,regulate the synergistic effect of multiple catalytic sites,and achieve efficient and selective conversion of substrates to target products.The experiment in this paper mainly includes the following four aspects:1.A emulsion system with water as reaction medium was developed to catalyze aromatic amine andα-Strategies for selective synthesis of nitrogen heterocyclic compounds using ketone esters.14 substrates were efficiently and selectively converted into 1,2,3,4-tetrahydroquinoline derivatives in 12Ca stabilized W/O emulsion,and 12 3-pyrroline-2-one derivatives were successfully obtained in CTAB stabilized O/W emulsion.The formation of the emulsion system will automatically and intelligently package insoluble catalysts and substrates to intelligently control the acidity required for the reaction process,and the formation of the emulsion will increase the reaction contact area,and the reaction selectivity and yield will be greatly improved accordingly.The establishment of this method has successfully expanded the application of emulsion system in selective catalysis,and also provided a more efficient,simple and green method for the synthesis of nitrogen heterocycles.2.A W/O type phase inversion Pickering lotion system,which is costabilized by DDAB and SiO₂ nanoparticles,was established to intelligently control the formation of the reaction intermediate of aniline and pyruvic acid,so that it can be efficiently and selectively transformed into the target product.Under optimal conditions,10 substituted 2-methylquinoline-4-carboxylic acid derivatives were obtained.This method does not require the addition of catalysts and other organic solvents,avoiding environmental pollution and reducing economic costs.At the same time,nano-SiO₂in the emulsion system can be recycled,providing a green,novel and valuable strategy for the synthesis of nitrogen heterocyclic compounds（quinoline derivatives）.3.A green degradable emulsion system was established to replace the traditional emulsion system,and the classical Doebner reaction of aniline,pyruvic acid and benzaldehyde was realized in this system.After screening the optimal conditions,six membered nitrogen heterocyclic compounds（quinoline derivatives）were successfully obtained in the ASN stabilized W/O emulsion system,and five membered nitrogen heterocyclic compounds（3-pyrroline-2-one derivatives）were successfully synthesized in the TW20 stabilized O/W emulsion system.4.A continuous flow experimental method assisted by microreactors has been established to complete the interaction between aniline andα-Efficient and selective conversion of ketone esters to nitrogen heterocyclic compounds.The liquid drop encapsulation process of catalyst and substrate is realized to further realize the transformation from the traditional multi-step static organic reaction to the continuous flow reaction.The 1,2,3,4-tetrahydroquinoline derivatives were efficiently and selectively synthesized in the flowing W/O type emulsion microreactor formed by 12Ca,and the efficient synthesis of 3-pyrroline-2-one derivatives was realized in the flowing O/W type emulsion microreactor formed by CTAB.