Research On Synthesis Of Unsaturated Alkenyl Ethers And Alkenyl Sulfides

Both alkenyl sulfide and alkenyl ether are significantly important compounds,which have been extensively used as the versatile synthons in organic synthetic chemistry to synthesize natural and bioactive molecules.In recent years,numerous efforts focused on synthesis of alkenyl ether and alkenyl sulfide have drawn a lot of attentions by chemists,and great progresses have been acquired.Among previous reports,most of strategies have relied on the promotion of precious metal,such as Au,Ag,Rh,or Pd.Though a number of target products have been obtained via precious metal-catalyzed methods,the utilization of that required a high standard for experimental operation and equipment,and it would be limitated for a wide application of method.While,to our knowledge,a metal-free-catalyzed synthesis of alkenyl ether and alkenyl sulfide has been rarely reported.A metal-free-catalyzed strategy could significantly reduce the cost and expand the applicability,which is worthy of further exploration and is also a challenging and significant research topic.Here in this paper,we made investigated on synthesis of alkenyl ether and alkenyl sulfide based on the literature and previous researches in our lab,and the details were described as followed:(1)The previous reports focused on synthesis of alkenyl ether or alkenyl sulfides were summarized.Then,the purpose,significance and main content of this paper were described.(2)Systematically studies on synthesis of alkenyl ether were perfo rmed in this work.Firstly,a series of optimized experiments were performed by using benzaldehyde and methanol as template substrates,and then an optimal condition was obtained,descrbed as followed:benzaldehyde(0.5 mmol),methanol(1.0 mmol),potassium hydroxide(2.0 equiv),dimethyl sulfoxide(2.5 mL,35 mmol),120℃,5min.After that,we examined the toleration of aldehydes and benzophenones.The applicability range of alcohol substrates was also investigated and provided good results.Finally,based on control experiment results and literatures,a possible reaction mechanism was proposed.(3)The synthesis of unsaturated alkenyl sulfide compounds was studied systematically in this work.First,a series of optimized experiments were performed by using benzaldehyde and n-butyl mercaptan as template substrates,and an optimal condition was obtained,descrbed as followed:benzaldehyde(0.5 mmol),n-butyl mercaptan(1.0 mmol),potassium hydroxide(2.0 equiv),dimethyl sulfoxide(2.5 mL,35 mmol),120℃,5 min.The application range of carbonyl and thiol substrates were studied.At last,a possible reaction mechanism is proposed based on a series of control experimental results.