4635-87-4Relevant articles and documents
A process for preparing 3 - pentenenitrile method
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Page/Page column 9-13, (2019/05/16)
The invention discloses a 2 - methyl - 2 - buten preparation 3 - pentenenitrile method, said method comprising: the 2 - methyl - 2 - buten in catalyst and double-[...] ligand under catalytic action of the isomerization reaction, in order to obtain 3 - pentenenitrile, wherein said catalyst is a transition metal with low monodentate phosphorus ligand complex. The method is simple in operation, easily available raw materials, high yield.
Method for generating 3-pentenenitrile through isomerization reaction of 2-pentenenitrile
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Paragraph 0051; 0052, (2019/04/29)
The invention discloses a method for generating 3-pentenenitrile through isomerization reaction of 2-pentenenitrile. The method is characterized by including the following steps of mixing 2-pentenenitrile, a catalyst, bidentate phosphorus ligand, Lewis acid and a solvent to obtain a reaction system, making the reaction system in the first step react under the reaction pressure of 0.1-0.5 Mpa and the reaction temperature of 80-150 DEG C under the condition of nitrogen protection, separating the unreacted 2-pentenenitrile from the product (3-pentenenitrile) through decompression distillation after the reaction ends. The method has the advantages of increasing the target product yield, shortening the reaction process and reducing the product separation difficulty.
Process for producing pentenenitriles
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Page/Page column 26, (2018/04/20)
The invention provides methods useful in the industrial scale process for hydrocyanation of butadiene to adiponitrile for recycle of unwanted byproduct 2-methyl-3-butenenitrile (2M3BN) by conversion to process intermediate pentenenitrile. The invention provides a process for generating catalysts useful for carrying out the hydrocyanation of butadiene to adiponitrile, the process comprising contacting the 2M3BN and a solution of a nickel-ligand catalyst in cis-2-pentenenitrile (cis-2PN), trans-2-pentenenitrile (trans-2PN), or a mixture thereof. The improved methods of the invention can provide improved catalyst solubility for bidentate ligands without a requirement for a Lewis acid catalyst promoter such as zinc chloride to be present.
Theoretical and experimental study of the nickel-catalyzed isomerization of 2-Methyl-3-butenenitrile and the effect of a Lewis acid
Liu, Kun,Liu, Kai-Kai,Cheng, Mu-Jeng,Han, Ming-Han
, p. 29 - 38 (2016/08/25)
A combined experimental and theoretical study was conducted to investigate the isomerization of 2-methyl-3-butenenitrile (2M3BN) to 3-pentenenitrile (3PN) and to 2-methyl-2-butenenitrile (2M2BN) catalyzed by nickel diphosphine complexes. Ni(1,4-bis(diphenylphosphino)butane) (dppb) was identified as the most reactive catalyst among the complexes that we examined experimentally. Quantum mechanics (density functional theory) was then used to study the two isomerization mechanisms catalyzed by this complex. We find that for the 2M3BN?→?3PN isomerization, the reaction is initiated with [Formula presented] bond cleavage, followed by an allyl direct rotation and [Formula presented] bond reformation. For the 2M3BN?→?2M2BN isomerization, the most energetically favorable pathway begins with [Formula presented] bond activation, followed by a π-σ-σ-π allyl rearrangement and [Formula presented] bond reformation. Our proposed mechanism for the 2M3BN?→?2M2BN isomerization is slightly different (yet energetically more favorable) than that described in previous studies, where it has been suggested that 2M2BN is obtained through a π-σ-σ allyl rearrangement rather than a π-σ-σ-π type rearrangement. Additionally, we investigated the effect of Lewis acids in the 2M3BN?→?3PN isomerization, which has been shown in most experiments to attenuate the reaction. Notably, our calculations indicated that ZnCl2, which is used as a model Lewis acid, actually reduces the barriers for all elementary steps. However, the effective kinetic barrier for the isomerization increases from 23.7 (without ZnCl2) to 24.0?kcal/mol because of the formation of a very stable Ni(π-allyl) ([Formula presented]2) intermediate, causing a decrease in the reaction rate. This theoretical result was further confirmed by our own experiments.
A using 2-methyl-3-crotonization of a method of isomerizing hexanedinitrile;
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Paragraph 0022; 0023, (2017/02/24)
The invention discloses a method for synthesizing adiponitrile by isomerization liquid of 2-methyl-3-crotononitrile. The method comprises steps of (1) carrying out isomerization reaction on 2-methyl-3-crotononitrile in the presence of zero valent nickel catalyst, phosphorus-containing ligand and lewis acid so as to generate 3-pentenenitrile; (2) mixing the isomerization liquid obtained in step (1) with hydrocyanic acid for reaction so as to generate the product containing adiponitrile. In the presence of zero valent nickel catalyst, phosphorus-containing ligand and lewis acid, the 2-methyl-3-crotononitrile generates 3-pentenenitrile through isomerization reaction; as the composition of the isomerization liquid is relatively the same as the material for secondary hydrocyanic reaction, the method directly adopts the isomerization liquid and hydrocyanic acid for reaction so as to synthesize adiponitrile. Therefore, the method saves the step of separating and purifying 3-pentenenitrile from the isomerization liquid, thus greatly lowering equipment cost and production cost, and reducing poisoning caused by zero valent nickel catalyst and phosphorus-containing ligand.
Synthetic hexanedinitrile pyprolylene law inhibiting phosphorus containing ligand degradation method
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Paragraph 0023-0024, (2017/04/03)
The invention discloses a method for inhibiting degradation of phosphorus containing ligand in process of synthesizing adiponitrile via a butadiene method, and the method comprises the step of adding organic alkali in isomerization reaction and secondary hydrocyanation reaction, wherein the organic alkali comprises triethylamine, diethylamine, dimethylamine, hexamethylenediamine, pyridine, phenylamine, phenylamine and N,N-dimethylaniline or N,N-diethylaniline. According to the method, organic alkali is added in the isomerization reaction and secondary hydrocyanation reaction, then the degradation of the phosphorus containing ligand in the isomerization reaction and secondary hydrocyanation reaction is effectively inhibited, and the degradation rate of the phosphorus containing ligand is controlled within 5%, so that the magnitude of recruitment of the phosphorus containing ligand is decreased, the separation recovery rate of the zero-valence nickel catalyst and the phosphorus containing ligand is improved at the same time and the raw material cost for synthesizing the adiponitrile via the butadiene method is reduced; and the method provided by the invention does not influence the conversion rate and the selectivity of the isomerization reaction and secondary hydrocyanation reaction.
A synthesis section of the mixed solution directly isomerization of 2-methyl-2-crotonization method
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Paragraph 0004, (2017/02/09)
The invention discloses a method for synthesizing 2-methyl-2-butenenitrile through direct isomerization of alkene-nitrile mixed liquid. The method is characterized in that isomerization reaction occurs by adding calcium-containing inorganic base to the alkene-nitrile mixed liquid containing 2-methyl-3-butenenitrile and 3-pentenenitrile so as to generate a product containing the 2-methyl-2-butenenitrile. According to the method, the process of purifying the 2M3BN through reduced pressure rectification is omitted, the calcium-containing inorganic base is used as a catalyst and directly isomerizes the alkene-nitrile mixed liquid containing the 2M3BN and 3PN into the 2M2BN, and the reaction conversion rate and the selectivity are greater than 95% respectively. Compared with a conventional method, the method has the advantages that the rectification separation process of the alkene-nitrile mixed liquid is omitted, so that the whole process route is shortened, the technological process is simplified, the equipment cost and the production cost are reduced, the calcium-containing inorganic base is used as the catalyst, low in price and easy to obtain and can be recycled, and industrial wastewater, waste gases and residues are basically not generated in the whole technological process.
PENTENENITRILE ISOMERIZATION
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Paragraph 0038; 0056, (2015/11/18)
Disclosed is a process for isomerizing cis-2-pentenenitrile to 3-pentenenitrile in the presence of a non-aluminium metal oxide catalyst, wherein: (a) the metal in the catalyst has an oxidation state in the range from +1 to +4; (b) the metal has a cation radius in the range from 0.35 to 1.0 ?; (c) the metal of the catalyst has a polarising power, C/r, is in the range from 2 to >8, wherein C is the charge of the metal and r is the ionic radius in ?; (d) the bond network of the catalyst has a % ionicity of >20; (e) the metal oxide has an acidity strength in the range from strong to very weak; and (f) the metal oxide has a basicity (nucleophilicity) strength of weak to strong.
A metal-ligand cooperative pathway for intermolecular oxa-michael additions to unsaturated nitriles
Perdriau, Sébastien,Zijlstra, Douwe S.,Heeres, Hero J.,De Vries, Johannes G.,Otten, Edwin
supporting information, p. 4236 - 4240 (2015/04/14)
An unprecedented catalytic pathway for oxa-Michael addition reactions of alcohols to unsaturated nitriles has been revealed using a PNN pincer ruthenium catalyst with a dearomatized pyridine backbone. The isolation of a catalytically competent Ru-dieneamido complex from the reaction between the Ru catalyst and pentenenitrile in combination with DFT calculations supports a mechanism in which activation of the nitrile through metal-ligand cooperativity is a key step. The nitrile-derived Ru-N moiety is sufficiently Br?nsted basic to activate the alcohol and initiate conjugate addition of the alkoxide to the α,β-unsaturated fragment. This reaction proceeds in a concerted manner and involves a six-membered transition state. These features allow the reaction to proceed at ambient temperature in the absence of external base.
PENTENENITRILE ISOMERIZATION
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Paragraph 00039, (2014/06/24)
Pentenenitrile oligomers formed in a process for isomerizing cis-2-pentenenitrile to 3-pentenenitrile are minimized in the presence of an aluminium oxide catalyst. The process comprises providing an aluminium oxide catalyst having an alkali metal and/or alkaline earth metal and/or iron content, measured in the form of alkali metal oxide and/or alkaline earth metal oxide and/or iron oxide, respectively of less than 5000 ppm by weight.
