Preparation And Properties Of Traditional Mesoporous Silicon-based Supported Pd Catalysts And Novel Imine-type Organic Molecular Cage Catalysts

Developing special heterogeneous materials to improve the atomic efficiency of transition metal catalysts is an important problem in organic synthesis.Due to their simple separation and easy recovery,and their catalytic reaction activity is not affected in the reaction,it has been explored by scientific researchers and their engineers in scientific research and production application.In this paper,the construction of two types of heterogeneous catalysts was studied:(1):Inspired by the unique hollow shell structure and the high stability of porous organosilane auxiliary materials,By using TEOS(tetraethyl orthosilicate)as a silicon source and CTAB(cetyltrimethylammonium bromide)as a template,through the process of etching and removing the template,the inner wall was modified with 2-(diphenylphosphino)ethyl triethoxysilane,and the derivative diphenylphosphine was crosslinked with Pd(OAc)₂to construct a mesoporous silica-based heterogeneous catalyst with hollow mesoporous structure HS@Pd PPh₂@MSN.Structural analysis and material characterization showed that there was a single well-defined point Pd²⁺active substance in the inner shell and provided HS@Pd PPh₂@Compared with other core/hollow shell solid catalysts,MSN showed excellent catalytic ability and activity.Catalyzer HS@Pd PPh₂@MSN obtained a series of diaryls in the effective Suzuki Miyaura cross-coupling reaction of 1-iodo-4-methoxybenzene and phenylboronic acid with a yield of 95%.In addition,catalyst HS@Pd PPh₂@MSN can also be recovered after filtration and washing and can be recycled ten times in the Suzuki Miyaura coupling reaction.Its activity remains unchanged in the reaction.This simple and cost-effective structure HS@Pd PPh₂@MSN nanomaterials have broad application prospects in fine chemical engineering,which is in line with the concept of a green chemical process.(2):Inspired by the classical and readily available chiral organic molecular cage CC3,and modified it.We first synthesized 1,3,5-tris(p-formylphenyl)benzene,and then reversibly condensed it with chiral cyclohexanediamine to innovatively synthesize CC3-4Ph chiral organic molecular cage.After the CC3-4Ph was synthesized into RCC3-4Ph by a simple reduction operation,its unique steric configuration was used to coordinate nickel ions through the chelating ability of cyclohexanediamine.Its application to the Michael addition reaction.The results show that the unique chiral structure of the molecular cage and the assistance of the dinitrogen centre can catalyze the Michael addition reaction with high reaction efficiency and asymmetric selectivity,thereby constructing high enantioselective Michael addition products,substrates It has a wide range of applications and a wider application prospect...