Catalyst-and Oxidant-Free Desulfonative C-P Coupling Reaction

Organophosphorus compounds are a large class of very important organic compounds with a wide range of bio-physiological activities.Phosphorus widely exists in drugs,pesticides and natural products.It can also be used as organic functional materials,ligands,organic catalysts,and organic synthesis reagents.It is an important structural skeleton for the construction of carbocyclic and heterocyclic compounds in organic synthesis.Therefore,the synthesis of phosphorus-containing compounds has always been a very important research area in organic chemistry,and continues to make chemists to develop new,highly efficient synthetic methodologies.On the other hand,the sulfone group in the sulfone compound has a good leaving ability.It can prolong the carbon chain through the reaction of bases and electrophilic reagents.Therefore,the coupling reaction of desulfonylation is widely applied to organic synthesis.In this thesis,we use sulfone compounds and phosphine oxides to generate a series of C-P bonds in the absence of transition metals,catalysts and oxidants.First,we designed desulfonylation coupling reaction of diphenylphosphine oxide with 1-methyl-4-((phenylethynyl)sulfonyl)benzene.We have determined the optimal conditions for the reaction after a series of conditions(such as bases,solvents)screening:cesium carbonate(Cs2CO3)as a base,tetrahydrofuran(THF)as a solvent for reaction at room temperature,we can get the best results.And a series of polysubstituted alkynylphosphine oxides and phosphonate compounds were finally obtained in 42-98%isolated yield.Subsequently,a preliminary exploration of the reaction mechanism was conducted and a possible reaction mechanism was proposed.Moreover,we have also extended this strategy to alkenyl and allyl sulfone compounds,and obtained alkenyl and allyl phosphine oxides in 45-73%yield and 64-96%yield.All the desired products were characterized by 1H NMR,13C NMR,31P NMR,HRMS,and the spectroscopic properties of the target compounds were studied and their spectral data were assigned.And one of them was unambiguously determined by X-ray diffraction analysis.This research has been published on Advanced Synthesis&Catalysis(2017,359,4141-4146.).