Ⅰ Pd/c-catalyzed Acylphosphine Decarbonylation Study Ⅱ Acylation Of Hydrogen Peroxide For The Synthesis Of Peroxyacetic Acid

Part 1: Triarylphosphines in organophosphorus compounds were one of the first phosphine ligands to be used in catalysis and have widespread utility.Phosphine ligands bound to transition metal centres often have unique electronic and Steric effects,thus allowing for a wide range of organic synthetic transformations.Combining atomic economy and practicality,transition metal-catalyzed intramolecular decarbonylation of acylphosphines is the optimal method for the construction of trivalent phosphine compounds.However,the conditions of transition metalcatalyzed decarbonylation reactions are mostly harsh and most of the catalysts chosen for the reactions are sensitive to air,so it is of practical importance to develop a new,inexpensive and mild catalyst system to achieve efficient decarbonylation for the synthesis of trivalent phosphine compounds.In this paper,we have used a commercially available,cheap and recyclable heterogeneous catalyst Pd/C as catalyst to achieve intramolecular decarbonylation of acylphosphines to trivalent phosphines under relatively mild conditions.Among the main works are:1.The optimum reaction conditions were obtained by examining the catalyst type,ligand,solvent,reaction temperature and time,using benzoyldiphenylphosphine as the substrate for the decarbonylation reaction.Under these conditions,a total of 31 substrates were examined and compatibility of the functional groups was achieved in moderate to excellent yields.When there are multiple functional groups containing carbonyl groups in the substrate,the decarbonylation of specific functional groups can be achieved in isolated yields of up to 98%.2.A series of extended experiments,including gram-scale preparation reactions,Pd/C catalyst recovery experiments,intermolecular competition experiments and reaction rate experiments,have demonstrated that the preparation of trivalent phosphine compounds using this method has good industrial prospects and high reactivity.3.The mechanism of the catalytic form of the Pd metal centre in the heterogeneous catalyst Pd/C has been investigated.It is hypothesised from the experimental conclusions that the reaction is initiated by a divalent Pd species initiating the catalytic cycle and that it is possible that the Pd species in the heterogeneous catalyst leaches into the system to participate in the reaction.Part Ⅱ: Peroxyacetic acid is widely used in the medical,epidemic prevention,food and pharmaceutical sectors for its strong bactericidal properties,especially in major epidemic prevention strategies such as SARS,avian influenza,field control of the new coronavirus and disinfection of epidemic sites.The problems that exist in the market today,such as the easy decomposition of peroxyacetic acid itself and the safety and corrosiveness of transport,have led researchers to search for new methods of preparing peroxyacetic acid.Therefore,it is particularly important to develop a long-lasting,stable and rapid method for the synthesis of peroxyacetic acid based on previous work.In this paper,we have developed two two-dose methods for the preparation and stability study of peroxyacetic acid,both using hydrogen peroxide acetylation for the synthesis of peroxyacetic acid.Among the main works are:1.In the study of binary liquid type peroxyacetic acid,we used the acetic acid oxidation method to investigate and optimise the reaction raw material ratio,catalyst selection,stabiliser,reaction time and other factors to synthesise a liquid-liquid dual agent peroxyacetic acid solution with agent A as peroxyacetic acid and agent B as water,p H adjuster and corrosion inhibitor.The solution was synthesized with a peroxyacetic acid concentration of ≈4% for agent A,which could be stored at room temperature for 180 days,and the PAA decomposition rate was only 8%.In addition,the PAA dilution solution mixed with agents A and B can be used continuously for 7 days with a PAA decomposition rate of <15%.2.In the study of binary solid type peroxyacetic acid,we use the acetyl activation method to synthesize peroxyacetic acid,in which we mainly overcome the solubility problem of traditional acetylation reagents in the reaction,the main component of B agent acetylsalicylic acid mixed with A agent hydrogen peroxide aqueous solution can be instantly generated in 5min concentration of 0.2% dilution of peroxyacetic acid,and the p H of the mixed peroxyacetic acid solution is neutral It can be used continuously for7 days,and is mildly corrosive to copper and aluminium,and basically noncorrosive to carbon steel.