Catalytic Synthesis Of Phosphoramide Compounds

Phosphoramide compounds are a kind of very important organic synthesis intermediates,which are widely used in medicine,chemical industry,manufacturing and other fields.Its traditional synthesis methods have many limitations,such as the introduction of halogen elements,the use of precious metal catalysts,long reaction times,tedious synthesis steps,and the use of large amounts of organic solvents,etc.,which affect the development of this field to a certain extent.Based on the concept of green chemistry,the development of economical,simple,green and efficient synthetic processes for phosphoramide compounds is a research hotspot in synthetic chemistry and green chemical industry.In this paper,diphenylphosphoryl azide（DPPA）and n-propylamine were used as template substrates to synthesize phosphoramide compounds based on two different methods:solvent method and grinding method,using lanthanum chloride（La Cl₃）and tris（pentafluorophenyl）,respectively)borane（B（C₆F₅）₃）as a catalyst in both liquid and solid phase systems enables the efficient preparation of the target compounds.In the solid phase grinding system,two grinding methods,manual grinding and planetary ball mill grinding,were adopted respectively.In the above two preparation methods,the reaction conditions were systematically optimized and screened first,and then the substrates were expanded under the optimal conditions,and the tolerance of phosphoryl azide and amine compounds were investigated respectively,and the possible reaction mechanism was finally proposed the specific research contents and conclusions are as follows:（1）The optimal catalytic system for the synthesis of phosphoramide compounds by solvent method:in air atmosphere,10 mol%La Cl₃ is used as catalyst,1.0 equiv.of Na HCO₃ is used as basic additive,and the reaction is carried out in DCE at 40°C.（2）The optimal catalytic system for the synthesis of phosphoramide compounds by grinding method:in air atmosphere and room temperature,5 mol%B（C₆F₅）₃ is used as catalyst,1.0equiv.of Na HCO₃ is used as basic additive,and a small amount of DCE is used as liquid Additives,the ratio of reactant dosage is 1:4,the grinding time is 20 min,the speed of the ball mill is 300 r/min,and 25 small steel balls of two sizes（5 mm and 8 mm in diameter,respectively）are used at the same time.（3）Using solvent method and grinding method,respectively,to explore the activity and product selectivity of different azides and amine compounds in the optimal catalytic system,a series of phosphoramide compounds were prepared,product yields up to 99%,and FT-IR,¹H NMR,¹³C NMR Its molecular structure was systematically characterized by means of HR-MS and so on.The results showed that both the solvent method and the grinding method showed good tolerance and applicability for different reaction substrates.Moreover,the grinding method can make the reaction time shorter,the operation simpler,and the product yield higher.