Study On The Mechanism Of Benzophenone And Magnesium Under The Action Of TMSCl

Compounds containing carbonyl groups such as aldehydes and ketones are a kind of basic substances in nature.They have the advantages of wide sources,low prices and easy availability.At the same time,the electrophilicity of carbonyl carbon and the acidity of α-hydrogen make these compounds become a very important raw material for organic synthesis.In this thesis,benzophenone is used as a template compound,and the formation mechanism of various types of products generated by benzophenone and metal magnesium in the presence of trimethylchlorosilane(TMSCl)are mainly studied.Since the reaction process has experienced high-energy free radicals and negatively charged intermediates,we believe that the reaction can generate more than 10 products.There are many formation mechanisms for these products,and some products even have as many as five formation mechanisms.It involves multiple forms,such as Clemmensen reduction,Mc Murry coupling,pinacol coupling,etc.This not only represents the high degree of complexity in the control of the reaction,but also shows the research potential of the reaction.It is necessary to conduct in-depth research on the formation mechanism of these products.Studying the formation path and mechanism of these products will help us better understand the form of carbonyl compounds and metallic magnesium under the action of trimethylchlorosilane,deepen our understanding of the reaction system,and better serve the main body of the thesis.At the same time,studying this content can also fill in the blanks of this part of the research content,which has greater research significance to a certain extent.This paper mainly separated and determined 10 reaction products produced by benzophenone,magnesium metal and TMSCl under different conditions,and analyzed and verified the formation mechanism of the products respectively.At the same time,the influence of these conditions on the type and yield of reaction products was studied by changing the amount of metal and the state of existence,temperature,solvent,solvent water content,amount of trimethylchlorosilane,additives and feeding methods.The specific research content is as follows:1.This article believes that the formation mechanism of some products is different from the mechanism proposed in the literature,and there are new production pathways,such as product2.In this paper,tetraphenylethylene glycol is designed to react with methyl acrylate in the presence of sodium hydride at room temperature,and products 12 and 13 can be obtained with yields of 23% and 20%,respectively,further verifying the mechanism of product 2 can well explain the mechanism we proposed,such as the silyl ether and alcohol compounds produced by the reaction.2.The formation mechanism of product 11 has not been reported in the literature.According to the analysis of experimental results,this paper expounds its possible mechanism.At the same time,an experiment was designed to extract hydrogen from diphenyl ether and add TMSCl to verify it.Product 11 was not obtained.According to this result,the corresponding mechanism proposed is denied.3.For other reaction products,we believe that the formation mechanism is the same as that proposed in the literature,and we have also conducted a logical analysis of their rationality,which is more consistent with the experimental results,such as diphenylmethane and tetraphenylethylene produced by the reaction.4.This article also summarized the production rules of related products.Combined with the data in Table 1,the results of experiments 1,3,and 9 show that the dropwise addition method,when the amount of TMSCl is small and contains trace amounts of water,is more conducive to the production of product 2.The results of experiments 1 and 3 show that there is more TMSCl and the water content of the system Product 3 is more produced under less conditions.The results of experiments 1,2,3,and 6 show that the low temperature,particularly large water content,and small amount of TMSCl are beneficial to the production of coupling product 5.The results of experiments 1 and 10 shows that the one-pot method and more magnesium powder are more conducive to the production of product 9.At the same time,the results of experiments 1 and 10 also show that the one-pot method and the increase in the amount of magnesium are also conducive to the production of product 6.