Study On Direct Addition Of Simlply Conjugated Diolefines

With the development of petrochemical industry in modern times，applicationrange of conjugated diolefines has been being gradually increased in pharmaceutical,oil additives and chemical synthesis fields and is steadily on the increase, being anintegral part of the positoin. Owing to special structures of conjugated dienes，intermediates in the additon process of them are different as reaction conditions andcatalyst systems change and finally results in different totally additional products.Controlling the direct addition of conjugated diolefines is not only the cruciallyscientific issues of organic science but also the practical value of realistic problems.Realizing the control of the direct addition of conjugated diolefines is helpful to moreeffectively utlize conjugated diolefines and reduce the waste of carbon resources.There is a multituide of additonal products represented by butadiene and isoprene ofsimply conjutaded diolfines but the majority need to be attained by selectivelyadditional reactions as the key point leys in selecting the proper catalysts. Recentlynew metal-organic catalysts represented by nickel and copper have been as a researchhot point for the direct addition of conjugated diolefines. These catalysts haveadvantages of cost-efficient, synthetic techology-simple and high catalytic efficiencyand are concerned by more and more people. The majority of reactions of Ni-basedcatalysts are carried on in organic facies and the synthetic techology of catalysts withhigh catalytic efficiency becomes the research hot spot rencently. Ni（0） phosphitecatalysts from Nickel and P-ligands are mainly used in alkenes addition espcially inconjugated diolefines addition. The control of the addition of butadienes withhydrogen cyanide is catalyzed by Ni（0） phosphite catalysts to adiponitrile and it is anoutstanding example of homogeneous caltalysts in industial applications，which is sofar the best available technology to produce adiponitrile in the word. Copper-basedcatalysts are mainly used in the direct addition of isoprene. Through our research weseek for the laws of the direct additon of simply cojutaded diolefines and the synthetictechologys of catalysts with high catalytic efficiency.The main work in the thesis is as follows: 1. The hydrocyanation of butadiene using Ni[P（C₆H₅O）₃]₄and P（C₆H₅O）₃as catalystswith acetone cyanohydrine（ACH） as HCN source was carried out in toluene. Theeffects of reactant molar ratios and temperature were observed. The mole ratio ofbutadiene to Ni[P（C₆H₅O）₃]₄was50:1and the mole ratio of butadiene to ACH was1.05:1. Under optimum conditions, the conversation of ACH was90%and the wholeselectivity to3-pentenenitrile（3PN） and2-methyl-3-butenenitrile （2M3BN） was85%with the reaction being terminated after3h. The ratio of2M3BN/3PN was2/1. Wesynthesized Ni[P（C₆H₅O）₃]₄, optimized catalyst composition and enhancedconversion efficiency of nickel salt into zerovalent nickel complexes.2. We successfully explored composite catalysts on cuprous chloride complexationwith lewis base such as triphenylphosphine for the hydrocyanation of butadiene.Composite catalysts overcomed the disadvantages which was hard to clear andserious corrosion when used cuprous chloride as a catalyst. Influence factors such astype of lewis base and addition of composite catalysts were investigated. The moleratio of butadiene to composite catalysts was20:1. The conversation of ACH was95%and the whole selectivity to3PN and2M3BN was90.2%.3PN and2M3BN wasin a7.5:1ratio. And the conversation of ACH was92.2%and the whole selectivity to3PN and2M3BN was87.5%with the reaction being enlarged in1L testing reactionunit. It showed that composite catalyst could effectively catalyze the hydrocyanationof butadiene.3. The isomerization of2M3BN to3PN was implemented with Ni（cod）2andP-ligands as catalysts. The effects of temperature, solvent and reactant molar ratioswere investigated. Under optimum conditions, the conversation of2M3BN was94%and the whole selectivity to3PN and4PN was83%with the reaction being kept at100℃for three hours. And the conversation of2M3BN was90%and the wholeselectivity to3PN and4PN was81.4%with reaction being enlarged in1L reactionunit. We explored the in-situ generation of Ni（0） phosphite catalyst for isomerizationof2M3BN. Under the same conditions, the catalytic effects accessed to that ofNi（cod）2with triphenylphosphine as catalysts. The method can effectively reducethe cost.4. The hydrocyanation of3PN was carried out in the presence of Ni[P（C₆H₅O）₃]₄or Ni[P（C₆H₄OCH₃）₃]₄as a catalyst. Influence factors such as temperature, solvent,co-catalyst and type of catalyst were investigated. The hydrocyanation of3PN usingNi[P（C₆H₅O）₃]₄and BPh₃as catalysts was carried out in toluene.3PN reached28.4%conversation and the selectivity to AdN was83%with the reaction being kept at70℃for three hours.5. It is the first discovery that there are several equilibrium states of3PN in theNi（0） catalytic systems.3PN can produce methylene glutaronitrile, adiponitrile andethyl-butanedinitrile in absence of HCN. The equilibrium state of3PN was affectedby factors such as reaction temperature and ligands. From three products possibleproduction routes, it produces1mole methylene glutaronitrile or adiponitrileaccording with2mole3PN being consumed, which results in reduction of desiredproduct selectivity. The discovery has important application value for controlling theselectivity to desired production.6. The isomerization of3-chloro^-1-butene into crotyl chloride was carried out in thehomogeneous catalytic systems containing cuprous salt and dimethylformamide.Influence factors such as temperature, type of catalyst and addition of catalyst wereabsorved. Under the optimum conditions, equilibrium constant of the title reactionreached3.88, which was kept at60℃for five hours. The reaction process wasmonitored in situ FTIR-ATR and the trend of variation was rising early but declininglater for the absorption at2365cm^-1and2340cm^-1. It inferred that the absorption wasinduced by the remiander of3-chloro^-1-butene losing chloride ion. We concluded thatthe essence of cuprous chloride catalyzing the isomerization of3-chloro^-1-butene layin aggravating the ionizing process of3-chloro^-1-butene.7. Cuprous chloride and acetic acid can effectively catalyze isoprene direct additionwith hydrogen chloride to isopentenyl chloride. Influence factors such as solvent,temperature, promoter and type of catalyst and addition of catalyst were investigated.Under the optimum conditions, the conversation of isoprene was93.32%and theselectivity to isopentenyl chloride was85.83%after the reaction being kept at10℃for four hours. What’s more, low hydrogen chloride concentrations achieved bycontrolling gas speed guarantes both high conversion and high selectivity, avoidingcatalyst deactivation at the process of reaction. Hydrogen chloride should be stopped admitting in when the conversation of isoprene accesses to90%and nitrogen gas orargon gas needs to replace the residual hydrogen chloride in the whole reactionsystem. That also contributes to gain the fewer dichloride production and the higherselectivity to desired production.