Study On The Phosphonyl Radical And Phosphinoyl Radical Reaction Prompted By Mn（OAc）₃

Reaction of the formation of C-P bond is always a subject of current interest. Organophosphorus is important class of compounds, and many of them possess biological activities. The importance of them in synthetic, agrochemical, and medicinal chemistry has been well documented throughout the years. There are many general methods for the preparation of carbon-phosphorus bonds. For example, Pudovik-type hydrophosphonation of alkynes under ionic, free radical or transition metal-catalyzed conditions. In this thesis, as part of our continuing efforts on the development of Mn(III) acetate based reactions, we studied the radical addition of dialkyl phosphites and diphenylphosphine oxide toα,β-unsaturated compounds and azaheterocyclic compounds, we also studied phosphinoyl radical addition intramolecular for the preparation of carbon-phosphorus heterocycles.In the second part of this thesis, we have successfully developed a Mn(III)-mediated regioselective phosphonation reaction of aryl alkenes bearing conjugated groups such as ketone, amide, nitro, or ester at theα-position. The reactions are straightforward and highly efficient. The results showed that the phosphonyl radical selectively added toα-position ofα,β-unsaturated compounds at first, followed the oxidation of intermediate, which leaving a proton to give the correspondingα-substitutedα,β-unsaturated compounds in good to excellent yields. The addition of phosphinoyl radical toα,β-unsaturated compounds gave the same results. We also found that compared with phosphonyl radical, the reactivity of phosphinoyl radical is low. Some reaction of phosphinoyl radical gave a better result than phosphonyl radical. In the third part of this thesis, we studied of the reaction of diphenylphosphine oxide and (E)-methyl 5-arylpent-2-enoates orβ-arylethylene styrene. We have developed a new Mn(III)-mediated regio- and stereoselective reaction for the preparation of 2-phosphoryl tetrahydronaphathalenes.β-Phenylethylene acrylates andβ-phenylethylene styrenes are good substrates to form 2-phosphoryl tetrahydronaphathalenes through phosphinoyl radical addition and cyclization processes. This straightforward reaction represents a new synthetic application of phosphinoyl radicals. The mechanism for this reaction is different from the previous chapter. Phosphinoyl radical adds to the ?β-position of the acrylate to form intermediate radical. This carbon-centered radical cyclized to the phenyl ring in trans fashion to yield aryl radical, which is oxidized with Mn(OAc)3 to give carbocation followed by deprotonation to afford product. The reaction ofβ-phenylethylene styrenes give a byproduct which is formed by adding an acetate anion to carbocation intermediate.In the fourth part of this thesis, we studied phosphonation of pyrimidinones and pyridinones. The reactions are performed under mild conditions using dimethyl phosphites and Mn(OAc)3 as the reagents, the protocol has demonstrated broad synthetic scope, and more importantly, the phosphonation process is regioselective. In the fifth part of this thesis, we explored intramolecular phosphinoyl radical addition for the preparation of carbon-phosphorus heterocycles. We have developed a new Mn(III)-mediated regioselective reaction for the preparation of dibenzophosphole derivatives and N-P heterocycle.