Study Of New Conversion Reactions Of Aldehydes Or Ketones C=O Bonds Involving DMSO As A Synthon

Dimethyl sulfoxide（DMSO）is widely used as a solvent for chemical reactions in organic synthesis because of its good solubility,low toxicity,high stability,low cost and easy availability.At the same time,DMSO is often used as oxidant.In recent years,DMSO has received increasing attention as a practical,safe and green synthetic block in the field of organic synthesis,and there are increasing reports of carbon,oxygen and sulfur sources provided by DMSO.In addition,the conversion reactions of aldehydes and ketones,as chemical raw materials from a wide range of sources,have received a lot of attention from organic synthesis workers.Among them,the conversion reactions of C=O bonds of aldehydes and ketones are of particular interest.The conversion of C=O bonds of aldehydes and ketones into C-O bonds,C-C bonds,C=C bonds,and C-N bonds has been intensively investigated in the past decades.However,the C=O bond conversions of aldehydes and ketones involving DMSO as a synthon have been reported very rarely.Therefore,it is important to develop the conversion reactions of aldehydes and ketones with C=O bonds involving DMSO as a synthon.Based on the study of previous work and our own interest,this paper explores the conversion of aldehydes and ketones C=O bonds involving DMSO as a synthon under the KOH-DMSO system using arylaldehydes,diarylketones and DMSO as raw materials.The main research contents are described as follows:1.Arylaldehydes or diarylketones,DMSO and O-nucleophiles were investigated for the synthesis of alkenyl ethers via a three-component reaction under the KOH-DMSO system.In this reaction,arylaldehydes or diarylketones provide a C atom,DMSO provides a=CH-synthon,and O-nucleophiles provide an O atom to construct C=CH-O structures via converting the C=O bonds of aldehydes and ketones to C=C bonds and simultaneously generating a C-O bond.A series of alkenyl ethers can be synthesized quickly（5 min）and efficiently（85-95%yield）using this method.Finally,through a series of controlled experiments and literature reports,we propose a possible mechanism for this reaction.2.Arylaldehydes or diarylketones,DMSO and S-nucleophiles were investigated for the synthesis of alkenyl sulfides via a three-component reaction in the presence of KOH.In this reaction,arylaldehydes or diarylketones provide a C atom,DMSO provides a=CH-synthon,and sulfur-containing nucleophilic reagents provide an S-atom,the C=CH-S structures were constructed by converting the C=O bonds of aldehydes and ketones to C=C bonds and simultaneously generating a C-S bond.Under the optimal reaction conditions,a series of alkenyl sulfides were synthesized.Based on the results of controlled experiments and related literature reports,we propose a possible reaction mechanism.3.The synthesis of N-vinylazoles via a three-component reaction from arylaldehydes or diarylketones,DMSO and azoles under the KOH-DMSO system was investigated.When the substrates were arylaldehydes,terminal N-vinylazoles were produced,in which the arylaldehydes C=O bonds were converted to C=C bonds and DMSO provided a=CH₂synthon;when the substrates were diarylketones,non-terminal N-vinylazoles were produced,in which the diarylketones C=O bonds was also converted to C=C bonds and DMSO provided a=CH-synthon.Under the optimal reaction conditions,a series of arylaldehydes,diarylketones,and azoles were successfully converted to the corresponding target products.A series of controlled experiments and literature reports were used to propose a possible reaction pathway for this reaction.4.The corresponding aryl acetaldehyde acetals or dialyl acetaldehyde acetals were synthesized from arylaldehydes or diarylketones,DMSO and diol compounds via three-component reaction in the presence of KOH.In this reaction,the C=O bonds of arylaldehydes or diarylketones were converted to C-C bonds,and DMSO provides a=CH-synthon.Under optimal reaction conditions,a series of arylaldehydes,diarylketones and diol compounds can be converted into corresponding target products.Through a series of controlled experiments and literature reports,we propose the possible reaction mechanism of this reaction.5.Arylaldehydes or diarylketones and their derivatives were studied under the KOH-DMSO system to produce the corresponding aryl acetals and diaryl acetals,respectively,by carbon-increasing homologation reactions.In this process the arylaldehydes or diarylketones C=O bonds are converted to C-C bonds and DMSO provides a=CH-synthon.The method is applicable to most arylaldehydes and diarylketones and has been successfully applied to gram-scale reactions.On the basis of a series of controlled experiments,we propose a possible mechanism for this reaction.6.The construction of benzene ring structures via monoatomic assembly from arylaldehydes and DMSO have been investigated,which was catalyzed by cuprous iodide under the KOH-DMSO system.In this reaction,arylaldehydes provide two C atoms and DMSO provides four=CH-synthons to construct the benzene ring structure by forming three C=C bonds and three C-C bonds.Under the optimal conditions,a series of arylaldehydes were able to produce the corresponding1,3-diarylbenzenes.The experimental mechanism of this reaction is still being further explored.