Novle Synthesis Of Phosphinoyl 1,3-butadienes And Derivatives

The phosphorus compounds which widely exist in bioactive compounds play a vital role in the life process.In the industrial and agricultural production,the phosphorus compounds are used as intermediates,additives,compounding agents of pesticide and fertilizer,flation,anti-fire and anti-oxidation,plasticity and toughness,metallic extraction,fabric wrinkle,flame retardant plastics.In the organic chemistry,phosphorus compounds with several active functional groups,show a special reaction activity.Moreover,these compounds are widely used in biological chemistry,material chemistry and organic synthesis.As such,the organophosphous chemistry appeals wide attention from the organic chemists and biological chemists.As representative functionalized organophosphorus compounds,phosphinoyl 1,3-butadienes are extensively used intermediates in organic reactions,including Michael addition with nucleophiles to afford allylic phosphonates,Diels-Alder reaction with dienophiles to form cycloadducts etc.However,the synthesis of these compounds is still limited due to the harsh reaction condition and complex operation.The development of environmental-friendly synthetic methods with high selectivity,good efficiency and easy operation is of great significance in both academic and industial field.In this thesis,substituted diphenylphosphine-α-allyl alcohols were synthesized firstly and further used for the preparation of phosphinoyl 1,3-butadienes.The coupling processes could be achieved via two different pathways including transition metal catalyzed Suzuki coupling and metal-free manner.In detail,three parts are included:(1)The general procedures for the synthesis of diphenylphosphine-a-allyl alcohols were developed:① Protection of alcohol hydroxyl groups in alkynol;② The introduction of different groups to alkynol to obtain substituted propargyl alcohols with butyl lithium under-78 ℃;③ reactions of substituted alkyne alcohols with chlorodiphenyl phosphine in the existence of pyridine to generate THP-protected phosphinoyl-allenic alcohol;④ Deprotection to obtain the designed diphenyl phosphine-a-allyl alcohols.(2)Suzuki couplings of substituted diphenylphosphinyl-a-allenyl alcohols and arylboronic acids with transition metal as catalyst were studied.After the optimization of reaction conditions,phosphinoyl 1,3-butadienes were obtained efficiently with 5 mol%of Pd(PPh3)Cl2 in neat water under reflux for 2 hours.No phase-transfer catalysts or additives were required for the heterogenous process.A mechanism via initial C(sp 3)-OH bond cleavage of the substrate to form π-allyl-palladium intermediates,and transmetallation with arylboronic acid,followed by reductive elimination to afford the product,is proposed.This approach exhibits the merits of environmental-benign,high efficiency and simple operation.(3)An efficient and metal-free strategy for the synthesis of chlorinated and brominated phosphinoyl 1,3-butadienes and derivatives were studied.Pre-prepared HCl/HBr solutions enabled the in situ rearrangement of phosphinoyl-a-allenic alcohols to conjugated vinyl cations,which afforded various novel polysubstituted phosphinoyl 1,3-butadienes in medium to excellent yields.The resulting products could be converted into multi-functionalized allylphosphine oxides;moreover,their couplings with electron-deficient arylboronic acid provided an more efficient approach to synthesize electron-deficient phosphinoyl 1,3-butadienes.