Nickel Catalyzed Alkylation Of Sulfones With Alcohols & The Synthesis And Application Of Ferrocene Derived 3D COFs

Transition metal complex catalysts play a very important role in organic synthesis,photocatalysis and electrocatalysis synthesis.Catalysts with excellent performance generally rely on rare precious metals such as ruthenium,rhodium,iridium,palladium and platinum.Cheap metals with abundant reserves such as iron,cobalt,nickel and manganese have unstable properties and changeable valence states,and their catalytic performance is far behind that of rare precious metals catalysts.In recent years,due to the decline of reserves,the difficulty of mining increases,the price of precious metals continues to rise,and some rare precious metals mineral reserves will be exhausted in 50 years.In the face of resource crisis,it is necessary and urgent to make every effort to improve the catalytic performance of cheap metals and achieve resource substitution.At the same time,designing and synthesizing three-dimensional functional materials with high stability and porosity,immobilizing homogeneous catalysts,and recycling them for reuse is an effective way to achieve sustainable resource utilization.Focusing on the research goal of cheap metal catalysis,this paper focuses on the application of nickel and iron,two abundant and cheap metals,in catalytic organic synthesis reactions and Fenton oxidation degradation of organic dyes.The research content is divided into two parts:（Ⅰ）The"hydrogen borrowing"alkylation reaction of alcohol to sulfone catalyzed by cheap nickel metalTheα-C-alkylation of sulfones is an important method to prepare complex sulfones from simple sulfones.The"hydrogen borrowing"reaction,which uses the cheap and easy primary alcohol as the alkylation reagent,completes the three steps of oxidation,condensation and hydrogenation in one pot,with only water as the by-product,which is a green reaction with high atomic and step economy.However,due to the easy departure of sulfone group,the"hydrogen borrowing"reaction of sulfone compounds often does not produce the targetα-C-alkylation product,but produces the elimination product alkene.Only two cases have been reported,both using noble metal ruthenium complex as catalyst.In order to explore the"hydrogen borrowing"reaction catalyzed by cheap metals,different types of nickel catalysts were screened using benzylsulfone and cyclohexyl methanol as model substrates.It was found that electron rich phosphine ligands were the key to regulating the catalytic activity of nickel,and the complexes formed in situ by Ni Cl₂（DME）and single phosphine ligand P（t-Bu）₃ were the best catalysts for this reaction.By carefully optimizing factors such as catalyst dosage,solvent,alkali,feed ratio,and reaction temperature,the optimal reaction conditions for the nickel catalytic model substrate were established.Under the optimal reaction conditions,the catalytic system has a wide range of substrate applicability.Various cyclic,linear,and branched fatty alcohols can be used as alkylation reagents.Aromatic methyl sulfones containing various substituent groups on the benzene ring can undergo"hydrogen borrowing"alkylation,Phenylethyl sulfone withα-carbon as secondary carbon can also be obtained with high yieldα-C-alkylation products.This reaction can be scaled up to the scale of grams.（Ⅱ）Oxidative degradation of organic dye Rhodamine B Fenton catalyzed by ferrocene-derived three-dimensional covalent organic frameworkFenton oxidation is an advanced oxidation technology for the treatment of organic pollutant wastewater.Ferric ion(Fe²⁺)can catalyze the decomposition of hydrogen peroxide（H₂O₂）to produce a large number of hydroxyl radicals（·OH）,which have high redox potential and can oxidize and degrade organic pollutants in wastewater.However,the concentration of Fe²⁺is too high,it is easy to form a large amount of iron sludge,causing secondary pollution.To solve this problem,this paper designed the first three-dimensional covalent organic framework material Fc-COF-1 based on the"sandwich"structure of ferrocene,in which the ferrocene structure can not only firmly fix Fe²⁺,but also improve the Fenton effect of Fe²⁺,and the stable and ordered pore structure is conducive to the adsorption and mass transfer of organic pollutants.The three-dimensional crystalline porous material Fc-COF-1 was successfully synthesized by solvothermal method using ferrocene double functional groups of tetraaldehyde monomer and1,3,5-3（4-amino phenyl）benzene as raw materials.Solid phase nuclear magnetic carbon spectroscopy,powder X-ray diffractometer,Fourier transform infrared spectrometer,transmission electron microscope,scanning electron microscope,specific surface and porosity analyzer,elemental analyzer and so on,the structure,pore size,morphology and iron content of the materials were tested and characterized.In order to compare the properties of different materials,two dimensional crystalline porous material Fc-COF-2 and polymer Fc-COP were synthesized based on single layer functional group synthesis of ferrocene.It was found that among the three materials,the 3D COF material Fc-COF-1 could produce more hydroxyl radicals and showed the strongest degradation ability to the organic dye Rhodamine B,and the degradation rate could reach more than 80%in 20 minutes without the aid of light.However,under the same conditions,the catalytic degradation rates of Fc-COF-2 and Fc-COP were only25%and 15%,and more than 60 min of light was needed to achieve a good degradation effect.The above two parts of the work are focused on the efficient use of cheap metals.In homogeneous nickel catalytic system,electron-rich alkyl phosphine ligands were selected to improve the catalytic activity of metals.In heterogeneous Fe-catalyzed Fenton oxidation system,the design and synthesis of ferrocene three-dimensional frame materials can not only fully expose the iron catalytic sites,but also facilitate the fixation and recovery of catalysts.In addition,we also tried to load nickel phosphine complex on ferrocene three-dimensional frame material to prepare Ni@Fc-COF-1.Unfortunately,this material is not suitable for catalyzing sulfone hydroalkylation reaction,so more reaction types need to be tried.