The Research On The Construction Of O-heterocyclic By ?-methyl Or ?-ethyl Ketone Coupling With Dimethylsulfoxide

O-heterocyclic are important branches of heterocyclic compounds and are commonly found in organic materials and natural product structures.Therefore,the construction of O-heterocyclic is widely concerned by scientists.In the past few years,the researchs on the construction of O-heterocyclic has achieved many innovative research results.Nevertheless,the synthetic conditions require a certain amount of specific transition metal as a catalyst(such as gold,silver,palladium,copper,cobalt,rubidium,iron,mercury and rare earth metals,etc.)and strong acid or alkali,which increased the reaction cost and operation difficulty.However,the synthesis of O-heterocyclic from simple materials and non-metallic conditions has not been reported.Therefore,it is of great significance to develop the method of O-heterocyclic reaction through simple and easy molecular substances in the absence of metal.In this paper,we developed and studied the novel conversion of a-methyl/ethyl of ketones and dimethylsulfoxide to the O-heterocyclic.The main contents are as follows:(1)The synthesises of furan and flavonoids were briefly summarized.Based on the results,we expounded the purpose,significance,and primary coverage of this research.(2)A systematic study for a-methyl ketone coupling with DMSO to construct O-heterocyclic was made.Firstly,by means of optimizing the factors,we obtained the best experimental conditions:acetophenone(0.5 mmol),tetrabutyl ammonium iodide(30 mol%),K2S2O8(2.0 equiv),DMSO(2.0 mL),8 h,120 ?.After that,the scope of a-methyl ketone and other aromatic ketones were examined.The results showed that the reaction had good compatibility with the aromatic a-methyl ketone.We also found that flavonoids were synthesized accidentally when acetone was substituted by hydroxyl group.Finally,the possible reaction mechanism is proposed through the analysis of a series of control experiments and the report of the comprehensive literature.(3)A systematic study for a-ethyl ketone coupling with DMSO to construct furan ring was explored.by means of optimizing the factors,the optimum reaction conditions were determined:benzyl acetone(0.5 mmol),K2S2O8(2.0 equiv),iodine/tetrabutyl ammonium iodide(30 mol%),dimethyl sulfoxide(2.0 mL),120 ?,8 h.Then the application range of aromatic a-ethyl ketone was investigated.After that,the possible reaction mechanism was proposed through the analysis of a series of control experiments and the reports of the comprehensive literature.