- Rational design of efficient steric catalyst for isomerization of 2-methyl-3-butenenitrile
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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.
- Han, Minghan,Liu, Kaikai,Wang, Tiefeng
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- PROCESS FOR ISOMERIZATION OF CIS-2-PENTENENITRILE TO 3-PENTENENITRILES
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Discontinuous or continuous isomerization of cis-2-pentenenitrile to 3-pentenenitriles, comprises isomerizing cis-2-pentenenitrile with tertiary amine compounds (I) and their mixtures. Discontinuous or continuous isomerization of cis-2-pentenenitrile to 3-pentenenitriles, comprises isomerizing cis-2-pentenenitrile with tertiary amine compounds of formula (I) and their mixtures. R1, R2 : H, linear or branched 1-5C-alkyl, 5-7C-cycloalkyl, hydroxyethyl or ethylene group bridging two N. [Image].
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Paragraph 0066-0068
(2017/01/02)
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- Process for Isomerization of CIS-2-Pentenenitrile to 3-Pentenenitriles
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The present invention relates to an improved process for batchwise or continuous isomerization of cis-2-pentenenitrile to 3-pentenenitriles in the presence of 1,4-diazabicyclo[2.2.2]octane as catalyst.
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Paragraph 0051
(2013/11/06)
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- Highly efficient nickel-catalyzed 2-methyl-3-butenenitrile isomerization: Applications and mechanistic studies employing the TTP ligand family
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A series of sterically and electronically fine-tuned, chelating diphosphine ligands were synthesized. The ligands are analogues of Triptyphos (TTP, 1), all based upon a variably 9,10-two-carbon-bridged 9,10-dihydroanthracene scaffold. These new TTP-type l
- Tauchert, Michael E.,Warth, Daniel C. M.,Braun, Sebastian M.,Gruber, Irene,Ziesak, Alexandra,Rominger, Frank,Hofmann, Peter
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experimental part
p. 2790 - 2809
(2011/07/29)
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- 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
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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.
- Swartz, Brett D.,Reinartz, Nicole M.,Brennessel, William W.,Garcia, Juventino J.,Jones, William D.
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experimental part
p. 8548 - 8554
(2009/02/03)
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- Highly selective hydrocyanation of butadiene toward 3-pentenenitrile
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A triptycene-based diphosphine ligand was synthesized in good yield following a new route. The corresponding Pt(II)- and Ni(0)-complexes were characterized. In butadiene hydrocyanation the tript-PPh2Ni(cod) catalyst leads to exceptionally high selectivities for the linear product 3-pentenenitrile, combining high activity for both hydrocyanation and isomerization. This one-step procedure could be the key toward process intensification. Copyright
- Bini, Laura,Mueller, Christian,Wilting, Jos,Von Chrzanowski, Lars,Spek, Anthony L.,Vogt, Dieter
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p. 12622 - 12623
(2008/03/14)
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- Isomerization of 2-methyl-3-butenenitrile with (bis-diphenylphosphinoferrocene)nickel compounds: Catalytic and structural studies
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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.
- Acosta-Ramírez, Alberto,Mu?oz-Hernández, Miguel,Jones, William D.,García, Juventino J.
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p. 3895 - 3901
(2007/10/03)
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- METHOD FOR PRODUCING 3-PENTENENITRILE
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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.
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Page/Page column 35-38; sheet 5
(2008/06/13)
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- PRODUCTION OF 3-PENTENENITRILE FROM 1,3-BUTADIENE
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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.
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Page/Page column 25-29; sheet 2
(2008/06/13)
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- METHOD FOR PRODUCING LINEAR PENTENENITRILE
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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.
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Page/Page column 72-76; sheet 2
(2008/06/13)
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- ISOMERISATION OF CIS-2-PENTENENITRILE TO FORM 3-PENTENENITRILE IN A REACTIVE DISTILLATION
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The invention relates to a method for the isomerisation of pentenenitrile in an educt flow. Said isomerisation is carried out on a heterogeneous catalyst in a distillation column, such that during the isomerisation, the isomerisation educt is enriched by distillation in relation to the isomerisation product in the reaction column of the distillation column.
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Page/Page column 13-14
(2008/06/13)
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- METHOD FOR THE ISOMERIZATION OF CIS-2-PENTENENITRILE TO FORM TRANS-3-PENTENENITRILE
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The invention relates to a method for the isomerization of 2-pentenenitrile to form trans-3-pentenenitrile in the presence of aluminium oxide as a catalyst. The invention is characterised in that the BET surface of the aluminium oxide is at least 50 m2/g.
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- PHOSPHONITE LIGANDS AND THEIR USE IN HYDROCYANATION
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Disclosed herein are processes for hydrocyanation and isomerization of olefins by using at least one multidentate phosphonite ligands, including organometallic phosphonite ligands with a Group VIII metal or Group VIII metal compound, and optionally, a Lewis acid promoter.
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Page/Page column 9-10
(2008/06/13)
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