20068-02-4Relevant academic research and scientific papers
Rational design of efficient steric catalyst for isomerization of 2-methyl-3-butenenitrile
Han, Minghan,Liu, Kaikai,Wang, Tiefeng
, (2020/10/22)
The catalytic isomerization of 2-methyl-3-butenenitrile (2M3BN), a model reaction in the DuPont process, has been performed using NiL4 (L=tri-O-p-tolyl phosphite) as a catalyst. The lowered catalytic activity in the isomerization with coexistence of 2-pentenenitrile (2PN) and 2-methyl-2-butenenitrile (2M2BN) indicates that both 2PN and 2M2BN are the catalyst inhibitors, and the quantitative relationship between the conversion of 2M3BN and the content of 2M2BN and 2PN is provided. DFT calculation results suggest that the inhibition effect is attributed to the generation of dead-end intermediates (2PN)NiL2 and (2M2BN)NiL2, both of which take nickel atom out of the catalytic cycle in the isomerization process. To suppress the inhibition effect, new catalytic intermediates are rationally designed based on their computational %Vbur. An efficient method that adding extra ligand 1, 5-bis(diphenylphosphino)pentane (dppp5) to the NiL4 catalyst is selected experimentally. Compared to the results obtained with NiL4 as catalyst, the (dppp5)NiL2 increases the conversion of 2M3BN from 74.5 % to 93.4 % at 3 h of reaction and provides a high selectivity to 3PN (> 98 %) at optimal conditions.
PROCESS FOR MAKING NITRILES
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Page/Page column 54; 89-93, (2012/02/01)
Adiponitrile is made by reacting 3-pentenenitrile with hydrogen cyanide. The 3- pentenenitrile is made by reacting 1,3-butadiene with hydrogen cyanide. The catalyst for the reaction of 1,3-butadiene with hydrogen cyanide to make 3-pentenenitrile is recycled. At least a portion of the recycled catalyst is purified by an extraction process, which separates catalyst degradation products and reaction byproduct from the catalyst.
Solvent effects and activation parameters in the competitive cleavage of C-CN and C-H bonds in 2-methyl-3-butenenitrile using [(dippe)NiH]2
Swartz, Brett D.,Reinartz, Nicole M.,Brennessel, William W.,Garcia, Juventino J.,Jones, William D.
experimental part, p. 8548 - 8554 (2009/02/03)
The reaction of [(dippe)NiH]2 with 2-methyl-3-butenenitrile (2M3BN) in solvents spanning a wide range of polarities shows significant differences in the ratio of C-H and C-CN activated products. C-H cleavage is favored in polar solvents, whereas C-C cleavage is favored in nonpolar solvents. This variation is attributed to the differential solvation of the transition states, which was further supported through the use of sterically bulky solvents and weakly coordinating solvents. Variation of the temperature of reaction of [(dippe)NiH]2 with 2M3BN in decane and N,N-dimethylformamide (DMF) allowed for the calculation of Eyring activation parameters for the C-CN activation and C-H activation mechanisms. The activation parameters for the C-H activation pathway were ΔH? = 11.4 ± 5.3 kcal/mol and ΔS? = -45 ± 15 e.u., compared with ΔH? = 17.3 ± 2.6 kcal/mol and ΔS ? = -29 ± 7 e.u. for the C-CN activation pathway. These parameters indicate that C-H activation is favored enthalpically, but not entropically, over C-C activation, implying a more ordered transition state for the former.
Practical synthesis of 3-amino-4,5-dimethylisoxazole from 2-methyl-2-butenenitrile and acetohydroxamic acid
Tellew, John E.,Leith, Leslie,Mathur, Arvind
, p. 275 - 277 (2012/12/26)
3-Amino-4,5-dimethylisoxazole was prepared from technicalgrade 2-methyl-2-butenenitrile and acetohydroxamic acid in a 62% overall yield on a multimole scale. The key features of this synthesis are (1) DBU treatment of the technical-grade nitrile mixture to provide a starting material of acceptable purity and (2) use of acetohydroxamic acid as an N-protected hydroxylamine equivalent. This operationally simple method provides the title compound in reasonable overall yield and free of contamination from the isomeric 5-amino-3,4-dimethylisoxazole.
Isomerization of 2-methyl-3-butenenitrile with (bis-diphenylphosphinoferrocene)nickel compounds: Catalytic and structural studies
Acosta-Ramírez, Alberto,Mu?oz-Hernández, Miguel,Jones, William D.,García, Juventino J.
, p. 3895 - 3901 (2007/10/03)
The catalytic isomerization of 2-metyl-3-butenenitrile to 3-pentenenitrile was carried out by (dppf)Ni species (dppf = bis-diphenylphosphinoferrocene) in the absence and the presence of Lewis acids. Studies in solution reveal the intermediacy of Ni(II) allyl complexes. Addition of Lewis acids such as BEt3 allow the crystallization and full characterization of the latter by X-ray diffraction studies.
METHOD FOR PRODUCING 3-PENTENENITRILE
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Page/Page column 35-38; sheet 5, (2008/06/13)
The invention relates to a method for producing 3-pentenenitrile, said method being characterised by the following steps: (a) 1,3-butadiene is reacted with hydrogen cyanide on at least one catalyst to obtain a flow (1) containing 3-pentenenitrile, 2-methyl-3-butenenitrile, the at least one catalyst, and 1,3-butadiene; (b) the flow (1) is distilled in a column to obtain a top product flow (2) rich in 1,3-butadiene, and a bottom product flow (3) that is poor in 1,3-butadiene and contains 3-pentenenitrile, the at least one catalyst, and 2-methyl-3-butenenitrile; (c) the flow (3) is distilled in a column to obtain a top product flow (4) containing 1,3-butadiene, a flow (5) in a side-tap of the column, containing 3-pentenenitrile and 2-methyl-3-butenenitrile, and a bottom product flow (6) containing the at least one catalyst; and (d) the flow (5) is distilled to obtain a top product flow (7) containing 2-methyl-3-butenenitrile, and a bottom product flow (8) containing 3-pentenenitrile.
PRODUCTION OF 3-PENTENENITRILE FROM 1,3-BUTADIENE
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Page/Page column 25-29; sheet 2, (2008/06/13)
The invention relates to a method for producing 3-pentenenitrile by means of the hydrocyanation of 1,3-butadiene, whereby 1,3-butadiene is reacted with hydrogen cyanide in the presence of at least one catalyst, and the resulting flow is purified by distillation, the bottom temperature not exceeding 140 °C during the distillation.
METHOD FOR PRODUCING LINEAR PENTENENITRILE
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Page/Page column 72-76; sheet 2, (2008/06/13)
The invention relates to a method for producing 3-pentenenitrile, characterised by the following steps: (a) isomerisation of an educt stream containing 2-methyl-3-butenenitrile on at least one dissolved or dispersed isomerisation catalyst to form a stream (1), which contains the isomerisation catalyst(s), 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile; (b) distillation of the stream (1) to obtain a stream (2) as the overhead product, which contains 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile and a stream (3) as the bottom product, which contains the isomerisation catalyst(s); (c) distillation of the stream (2) to obtain a stream (4) as the overhead product, which is enriched with (Z)-2-methyl-2-butenenitrile in comparison to stream (2), (in relation to the sum of all pentenenitriles in stream (2)) and a stream (5) as the bottom product, which is enriched with 3-pentenenitrile and 2-methyl-3-butenenitrile in comparison to stream (2), (in relation to the sum of all pentenenitriles in stream (2); (d) distillation of stream (5) to obtain a stream (6) as the bottom product, which contains 3-pentenenitrile and a stream (7) as the head product, which contains 2-methyl-3-butenenitrile.
PREPARATION OF (E)- AND (Z)-2-METHYL-2-BUTENOIC ACIDS
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Page 25, (2008/06/13)
A method has been developed to prepare (E)- and (Z)-2-methyl-2-butenoic acids (2M2BA) from a mixture of (E,Z)-2-methyl-2-butenenitriles (2M2BN) by the regioselective hydrolysis of (E)-2M2BN to (E)-2-methyl-2-butenoic acid (2M2BA) using enzyme catalysts having either a nitrilase activity or a combination of nitrile hydratase and amidase activities. The method provides high yields without significant conversion of (Z)-2M2BN to (Z)-2M2BA. The regioselective hydrolysis of (E)-2M2BN to (E)-2M2BA makes possible the facile separation of (E)-2M2BA from (Z)-2M2BN or (Z)-2-methyl-2-butenamide (2M2BAm), and the subsequent conversion of (Z)-2M2BN or (Z)-2M2BAm to (Z)-2M2BA.
Regioselective biocatalytic hydrolysis of (E,Z)-2-methyl-2-butenenitrile for production of (E)-2-methyl-2-butenoic acid
Hann, Eugenia C.,Sigmund, Amy E.,Fager, Susan K.,Cooling, Frederick B.,Gavagan, John E.,Bramucci, Michael G.,Chauhan, Sarita,Payne, Mark S.,DiCosimo, Robert
, p. 577 - 581 (2007/10/03)
Acidovorax facilis 72W nitrilase catalyzed the regioselective hydrolysis of (E,Z)-2-methyl-2-butenenitrile, producing only (E)-2-methyl-2-butenoic acid with no detectable conversion of (Z)-2-methyl-2-butenenitrile. (E)-2-Methyl-2-butenoic acid, produced in aqueous solution as the ammonium salt, was readily separated from (Z)-2-methyl-2-butenenitrile, and isolated in high yield and purity. The combination of nitrile hydratase and amidase activities of several Comamonas testosteroni strains were also highly regioselective for the production of (E)-2-methyl-2-butenoic acid from (E,Z)-2-methyl-2- butenenitrile.
