Studies On The Phosphonotrifluoromethylation And Phosphonoalkylation Of Alkynes

Organophosphorus compounds belong to an important class of compounds which have found wide applications in the fields of agriculture,medicine,materials etc.Traditionally,these compounds can be synthesized through the construction of carbon-phosphorus bonds.Therefore,the development of new and efficient methods for the formation of carbon-phosphorus bonds has attracted long-term interest.One approach toward the catalytic activation of organic molecules that has received attention recently is visible light photoredox catalysis.This kind of transformation is very attractive because of the generally mild conditions required for substrate activation and their suitability for green reactions.In a general sense,this approach relies on the ability of metal complexes and organic dyes to engage in single-electron-transfer(SET)processes with organic substrates upon photoexcitation with visible light.In this study,the application of visible-light photoredox catalysis for the construction of Csp2-P bonds,based on the bifunctionalization of alkynes was investigated.For clarity,this study was divided into two parts as summarized below:1.The three-component reaction involving alkyne,Togni reagent and trialkylphosphite was studied.The trifluoromethylation-phosphorylation of alkyne was achieved in one-pot to access 1-phosphine ester-2-trifluoromethylethylene derivatives.2.The three-component reaction involving alkynes,phthalmimide alkylates and trialkylphosphines was also studied.In this process,alkynes underwent sequential alkylation and phosphorylation in an efficient manner.The structures of all the products were characterized by NMR and Mass spectro scopic techniques.