Study On Synthesis Of Novel Carbon Based Solid Sulfonic Acids And Their Applications In Organic Reactions

The energy and environment pollution becomes one of the most seriousproblems nowadays.The aim of chemical industry is to get the single product bysimplify process.Under these circumstances,the solid acid catalysts which havewidely industry applications have been demanded.On the other hand,the traditionalliquid acids such as sulfuric acid,hydrochloric acid,p-toluenesulfonic acid,havemany disadvantages,including badly corruption of equipments,difficulties inremoving catalyst,non-reclaim of the catalyst.The reported catalyst such as thestyrene sulfonic resin had disadvantage of low thermal instability,that limited itsapplication area.Nafion owned excellent heat-resistant properties,but the high pricemade the catalyst impossible for the wider application in chemical industry.Inaddition,the inorganic solid acid catalysts including zeolite,silica-alumina andwater-containing niobium had some applications in the field of chemical industry,butthey had lower superficial trace acidity than traditional liquid acid,which did not meetthe demand of the chemical industry.In order to solve the problems as mentionedabove,we synthesizes a novel solid acid which has high acidity and high chemicalthermal stability.The main contents are as follows:1.The novel carbon based solid acids were synthesized through the carbonationand sulfonation of the aromatic compounds in sulfonic acid.Here,the sulfonic acidacted as both catalyst for the condensation of the aromatic compounds and thesulfonation agent.The condensation of the aromatic compounds should be takencompletely to form the solid-state compounds.So the proper aromatic compoundsshould be chose for the reactions and the proper reaction time and temperature shouldbe introduced for the synthesis of the novel carbon based solid acids.The effects of the amount of the sulfonic acid,reaction time,reactiontemperature and the concentration of the sulfonic acid were investigated to optimizethe reaction conditions using various aromatic compounds as raw materials first.Thenovel carbon based solid acid has been obtained with the acidity of 3.4mmol/g.Then,the catalytic activities of the novel carbon based acids were investigated through the acetaliztion and ketalization.The ketalization of cyclohexanone andglycol was investigated to figure out the optimal reaction conditions.Then thereactions between various carbonyl compounds and diols were carried out toinvestigate the catalytic activities of the novel carbon based acids.The results showedthat the catalyst owned very high activities for the reactions with very high yields.High activities,small catalyst amount and reusability are the key features of theprocedure.The catalyst was very efficient not only for the traditional five memberedring acetals,but also for the seven-membered-ring products.The catalytic activitieswere also very high for the synthesis of 1,3-benzodioxoles from catechol andcarbonyl compounds.The reactions accomplished in short time without thecopolymerization of the catechol and carbonyl compounds taken as the side reaction.The oxathioacetalization of carbonyl compounds and 2-mercaptoethanol undersolvent-free condition at room temperature was catalyzed by the novel carbon basedsolid acids.The results showed that the novel catalyst was very efficient for thereaction with the good to excellent yields in short time.Operational simplicity,without need of any solvent,small amount of usage,low cost of the catalyst used,high yields,applicability to large-scale reactions,reusability and chemoselectivity arethe key features of this methodology.2.The carbon based acids were synthesized through carbonization at hightemperature and the sulfonation in the sulfonic acid.The carbonation process shouldbe controlled well so that the carbon obtained could be sulfonation to produce thesolid carbon based acids.If the material was carbonized too deep,the sulfonationcould not be taken efficient.In the other hand,the solid acids could not be obtained ifthe carbonation was not carried out well.First,various sugars were used as the raw materials for the synthesis of the novelcarbon based acids.The carbonation and sulfonation conditions were investigated tooptimize the reaction conditions.The novel carbon based acid with both high acidityof 1.5mmol/g and thermal stability has been obtained successfully.Then,the catalyst was applied to the synthesis of tributyl citrate.The resultsshowed that the novel carbon based acids were all efficient for the reactions with high yield.The polysaccharide compounds such as starch and cellulose were difficult to becarbonized and carbonization products were still mixed with the sugar structure.Thesulfonic acid groups were also attached to the sugar structure in the sulfonation step,which made the sulfonic acid groups easy dropped during the catalytic procedure.Thecatalytic activities decreased quickly when the catalyst used for the first time,then theactivity remained for the sulfonic acid groups attached to the sugar structure droppedduring the reaction procedure for the first time.The novel carbon based solid acidsfrom glucose owned high activities and stability for the reactions with low catalystamount and high yield.The novel carbon based acids owned much higher activitiesand stability than the traditional solid acids for the active sites attached to the catalystthrough the chemical bonds.The quality of the product tributyl citrate was better thanthat produced by sulfonic acid,for the sulfonic acid was also efficient for the sidereactions such as dehydration.3.There were many drawbacks of the processed mentioned above.The reactionshould be taken under the stern conditions and the yields of the products were stillvery low.So the polymer carbon based sulfonic acids were synthesized usingnaphthalene compounds and P-toluenesulfonic acid as raw materials.First,the carbonbased sulfonic acids were synthesized through the naphthalene compounds.Theeffects of different naphthalene compounds,sulfonic acid,reaction temperature,andreaction time on the reactions were investigated to optimize the reaction conditions.The novel carbon based polymer acid has been obtained with the acidity of4.2mmol/g.The novel catalyst owned extremely high activities for the synthesis of acylalswith the average yields over 90% within several minutes.A comparative studyshowed that the novel catalyst has much higher activity than other catalysts with theadditional advantage of reusability.Besides,the novel catalyst has thechemoselectivity for the protection of aldehydes in the presence of ketones.Then,another carbon based sulfonic acids were synthesized by copolymerizationof p-toluenesulfonic acid and paraformaldehyde with sulfuric acid as catalyst.Thecatalytic activities of the novel carbon based acids were investigated through the Michael addition.The results showed that the catalyst was very efficient for theconjugate addition of amines to electron deficient alkenes with excellent yields inseveral minutes.Operational simplicity,no need of any solvent,low cost of thecatalyst used,high yields,reusability,excellent chemoselectivity and wideapplicability are the key features of this methodology.The catalyst also owned highstability with the catalytic activity remained when the catalyst was recycled for sixtimes.4.The hydrothermal carbonization procedure was introduced to instead of thetraditional carbonization.The traditional carbonation process was taken undernitrogen atmosphere at high temperature over 400℃.The waste liquid and gas wereproduced during the process,which made the carbonation yield was very low.Thehydrothermal carbonization procedure was carried out under much mild condition.The process was carried out at 150-180℃for 4h with much higher yield compared tothe traditional procedure.The effects of different sugar compounds,reaction temperature,reaction time,catalyst and catalyst amount on the reactions were investigated to find out the optimalreaction condition.Then the catalytic activities for the synthesis of biodiesel wereinvestigated carefully.The results showed that the catalyst was efficient for thereactions with high yield and reusability.