Synthesis Of Organic Phosphates Based On Electrophilic Phosphorus Species And Copper- Catalyzed Couplings

Organicphosphorus compounds are widely used in many fields such as chemistry,medicine and material because of their special structures and properties.Therefore,it is of great practical significance to develop a green and efficient method for the synthesis of these compounds.In this article,organophosphorus compounds were synthesized by electrophilic phosphination of electron-rich aromatics,aromatic thiols and arenols with electrophilic phosphination reagents.In addition,the C?sp?-P bonds can be constructed by the P-H/C-H cross-coupling catalyzed by copper nanoparticles supported on niobium oxide effectively.The main contents are as follows:?1?The electrophilic phosphine reagents were in situ generated from diaryl phosphine oxides and trifluoromethyl sulfonic anhydride,and the electrophilic phosphonations of these reagents with electron-rich aromatics,aromatic thiols and arenols respectively form the C-P,S-P and O-P bonds.This reaction is free of metal catalysts,performed under mild conditions?from room temperature to 60 ??,and has a board substrate scope.Both aromatics with electron-withdrawing and electron-donating groups can result in the desired products,and some heteroaromatics are also worked under identical conditions,The yields of products are up to 97%,and the possible reaction mechanism is also proposed.?2?The cross-couplings of alkynes and phosphonates can be catalyzed by niobium oxide-supported copper nanoparticles to efficiently afford alkynylphosphonates.Compared with the copper salts,copper nanoparticles are more active as the catalyst.Moreover,The activity of niobium oxide-supported copper nanoparticles is obviously better than that of other supporters.This may be due to niobium oxide as a supporter effectively inhibited the oxidation of copper and greatly improves the activity of the reaction.The structure,dispersion,valence state and the element proportion of the supported catalyst were characterized by TEM,XRD,XPS and ICP.In addition,it is found that the catalyst has a good absorption to phosphites based on IR characterization.It is proved that Nb₂O₅ can absorb phosphite esters to reinforce the interaction between the catalyst and substrates.Finally,according to the recovery experiment,the catalyst can be recycled for three times and the activity of the catalyst remains basically unchanged.