Straightforward Synthesis Of Bifunctional Phosphorus Phenols Via Phosphination Of In Situ Generated O-Quinone Methides

α-Diarylmethyl phosphine oxide compounds organophosphonate compounds and their derivatives have shown a wide range of applications in medicinal chemistry,agrochemistry,and organic synthesis.In addition,quinone methides is a useful active intermediate which are widely used in organic chemistry,material chemistry and biochemistry.In particular,ortho-quinone methides has important chemical properties and high biological activity which can be constructed important organic compounds and natural products via conjugation addition reaction such as hetero-Diels-Aider reaction and electrocyclization reactions and so on.As an important reaction for the construction of phosphorus compounds,a particularly attractive strategy is represented by the conjugate addition of a phosphorus nucleophile to an electron-deficient species,namely the phospha-Michael addition that has high application value.Considering the well document of nucleophilic addition reactions with secondary phosphine oxides（R₂P（O）H）,we conceived that the direct phospha-Michael addition of R₂P（O）H to o-QMs would be an attractive way to construct diarylmethyl phosphine oxides with both Lewis base and Brφnsted acid functional groups.In this study,we employed sesamol as the raw material and transformed it to the corresponding aldehydes compounds via Vilsmeier-Haack reaction.Subsequently,such aldehyde reacted with a Grignard reagent to decorate a phenyl group and formed a product with hydroxyl group.Then we obtained the desired precursor of ortho-quinone methides in the alkaline condition by the reaction between the previously obtained alcohol compound,p-toluenesulfonic acid and sodium p-toluenesulfonate.After that,under the similar conditions another 2-（phenyl（tosyl）methyl）phenols could also be synthesized with salicylaldehyde as the starting material.With the above mentioned consideration,a series of α-diarylmethyl phosphine oxide compounds were obtained by using 2-tosylalkyl phenol la and diphenylphosphine oxide 2a in the presence of K2CO3（1.2 equiv.）at 110℃ with the toluene as the soluvent.Next,to illustrate the synthetic utility of the diaryl phosphonate products,we first tested a large-scale experiment and transformed 3a to monomers for polymerization reactions.Finnaly,the structural information and thermal properties of the target products were investigated using Fourier Transform Infrared Spectrometer（FT-IR）,Nuclear Magnetic Resonance（NMR）,as well as High Resolution Mass Spectrometer（HR-MS）and the mechanism was also proposed.