Hydrogenation of nitrile in supercritical carbon dioxide: a tunable approach to amine selectivity

Chatterjee, Maya; Kawanami, Hajime; Sato, Masahiro; Ishizaka, Takayuki; Yokoyama, Toshirou; Suzuki, Toshishige M.

doi:10.1039/b913828e

Cited by 76 publications

(54 citation statements)

References 46 publications

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“…The distance between O and H is 1.906 Å in the absence of CO2 (Figure 10a) and it is extended to 1.945 and 1.952 Å when the CO2-coordinated clusters are formed ( Figure 10b, 10c), which clearly indicates that the intra-hydrogen bonding between 2-nitro group and amino group in 1 is weakened by the coordination of CO2 around 1. It is well known that an amine species has strong affinity with CO2 32,33 and it may cause the suppression of intra-hydrogen bonding, resulting in the increase of the reactivity of 2-nitro group in 1 as above-mentioned in Figure 2. The structures of CO2-coordinated clusters of 2NA and 4NA with three and four CO2 molecules were also calculated using DFT simulations (Figure 11).…”

Section: Molecular Simulationsmentioning

confidence: 97%

Molecular interactions with CO₂ for controlling the regioselectivity of liquid phase hydrogenation of 2,4-dinitroaniline

Yoshida

Tomizawa

Tachikawa

et al. 2014

Phys. Chem. Chem. Phys.

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Abstract:The catalytic hydrogenation of 2,4-dinitroaniline with a 0.5 wt% Pt/TiO2 was investigated in a multiphase medium of tetrahydrofuran (THF) pressurized by CO2 at different pressures and at 323 K. When CO2 pressure was raised, the overall rate of hydrogenation simply decreased but the selectivity to the desired product of 4-nitro-1,2-phenylenediamine increased. The noticeable enhancement of the selectivity to 4-nitro-1,2-phenylenediamine can be explained by chemical actions of CO2 molecules.In situ high-pressure FTIR and molecular simulations demonstrate that the dissolved CO2 molecules may interact with amino group of the substrate and weaken the intra-hydrogen bonding between the amino and 2-nitro groups, which results in the change of the relative reactivity of the two nitro groups, yielding the desired product in a higher selectivity. The change of the intra-and inter-molecular interactions between the substrate and CO2 molecules was theoretically examined by DFT calculation.2

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Section: Molecular Simulationsmentioning

confidence: 97%

Molecular interactions with CO₂ for controlling the regioselectivity of liquid phase hydrogenation of 2,4-dinitroaniline

Yoshida

Tomizawa

Tachikawa

et al. 2014

Phys. Chem. Chem. Phys.

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“…The carbamate salt is insoluble in BC organic phase, resulting in high selectivity to PEA. The formation of the carbamate salt from benzylamine and CO2 was reported by Chatterjee et al 15 and Yoshida et al 12 The formation of carbamate salt in hydrogenation of BN using NiCl2/NaBH4 in CO2 expanded ethanol at 303K was shown by Xie et al and they also observed an enhanced benzylamine selectivity.…”

Section: Possible Roles/functions Of Water and Co2mentioning

confidence: 73%

“…Previously, Chatterjee et al studied the hydrogenation of nitriles with a Pd/MCM-41 catalyst in supercritical CO2. 15 They reported its good performance for the selective hydrogenation of BC to PEA at 343 K and at a higher CO2 pressure of 10 MPa (H2 2 MPa), under which a high PEA selectivity of 98% was obtained at a conversion of 82% in 4 h. No time -conversion profile was presented in their work and so they did not mention the catalyst deactivation. They noted from the results of recycling test with another substrate of benzonitrile (BN) that the Pd/MCM-41 catalyst was stable although comparison was made at relatively high conversion levels ≈ 90%.…”

Section: Hydrogenation In Different Mediamentioning

confidence: 99%

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Selective hydrogenation of benzyl cyanide to 2-phenylethylamine over a Pd/Al₂O₃ catalyst promoted by synergistic effects of CO₂ and water

et al. 2015

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The selective hydrogenation of benzyl cyanide (BC) to the primary amine of 2-phenylethylamine (PEA) was investigated with a Pd/Al2O3 catalyst in different multiphase reaction media including n-hexane, water, and/or CO2. In neat n-hexane, the hydrogenation of BC occurs at a large rate but no PEA was formed and the secondary amine of N,N-bis(2-phenylethyl)amine (BPEA) was produced as the main product. The pressurization of n-hexane with CO2 decreased the rate of hydrogenation and the main product was BPEA. In this n-hexane -CO2 medium, the catalyst lost its activity during the reaction. When a similar volume of water was added to n-hexane, the rate of hydrogenation did not change so much but a small amount of the primary amine was detected to form in addition to the main product of BPEA. In contrast to these reaction media, a high PEA selectivity of > 90% was obtained and no catalyst deactivation occurred in an n-hexane -water -CO2 medium. The rate of hydrogenation was smaller than that in neat n-hexane but comparable to those in n-hexane -water and n-hexane -CO2 media. Those results show that synergistic effects appears on the selective hydrogenation of BC to PEA when both water and CO2 are included in the reaction medium. Possible roles and actions of water and CO2 have been discussed on the basis of the results of hydrogenation runs under different conditions and in situ ambient and high pressure Fourier transform infrared spectroscopy measurements that give light to molecular interactions of CO2 with reacting species.

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“…It is reported that a high selectivity of 95% to the primary amine can be achieved by supported Pd catalysts at a H 2 pressure of 1 MPa [28]. The use of dense phase CO 2 in hydrogenation of nitriles was recently investigated by Chatterjee et al [29]. They show that the selectivity to the primary and secondary amines can be tuned by CO 2 pressure and BA is produced with a Pd/MCM-41 catalyst in a high selectivity of about 90% at a CO 2 pressure of about 10 MPa.…”

Section: Introductionmentioning

confidence: 99%

A multiphase reaction medium including pressurized carbon dioxide and water for selective hydrogenation of benzonitrile with a Pd/Al2O3 catalyst

Yoshida

Wang

Narisawa

et al. 2013

Applied Catalysis A: General

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The hydrogenation of benzonitrile was studied with a Pd/Al 2 O 3 catalyst in the presence of pressurized CO 2 and water. This multiphase reaction system was effective for the selective production of the desired primary amine of benzylamine with no deactivation of the catalyst. The enhanced selectivity to the primary amine resulted from its transfer into water phase, which prevented the primary amine from reacting with an intermediate of imine into the secondary amine in the organic phase (benzonitrile). In addition, interactions of CO 2 molecules with the primary amine could also increase its selectivity. In the absence of water, the catalyst was deactivated by the accumulation of a carbamate salt on the surface of catalyst. But this deactivation was avoided by the addition of water because the salt was soluble in water and it did not deposit on the catalyst existing at interfacial layer between the water and organic phases.

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Hydrogenation of nitrile in supercritical carbon dioxide: a tunable approach to amine selectivity

Cited by 76 publications

References 46 publications

Molecular interactions with CO₂ for controlling the regioselectivity of liquid phase hydrogenation of 2,4-dinitroaniline

Molecular interactions with CO₂ for controlling the regioselectivity of liquid phase hydrogenation of 2,4-dinitroaniline

Selective hydrogenation of benzyl cyanide to 2-phenylethylamine over a Pd/Al₂O₃ catalyst promoted by synergistic effects of CO₂ and water

A multiphase reaction medium including pressurized carbon dioxide and water for selective hydrogenation of benzonitrile with a Pd/Al2O3 catalyst

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Hydrogenation of nitrile in supercritical carbon dioxide: a tunable approach to amine selectivity

Cited by 76 publications

References 46 publications

Molecular interactions with CO2 for controlling the regioselectivity of liquid phase hydrogenation of 2,4-dinitroaniline

Molecular interactions with CO2 for controlling the regioselectivity of liquid phase hydrogenation of 2,4-dinitroaniline

Selective hydrogenation of benzyl cyanide to 2-phenylethylamine over a Pd/Al2O3 catalyst promoted by synergistic effects of CO2 and water

A multiphase reaction medium including pressurized carbon dioxide and water for selective hydrogenation of benzonitrile with a Pd/Al2O3 catalyst

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Product

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Molecular interactions with CO₂ for controlling the regioselectivity of liquid phase hydrogenation of 2,4-dinitroaniline

Molecular interactions with CO₂ for controlling the regioselectivity of liquid phase hydrogenation of 2,4-dinitroaniline

Selective hydrogenation of benzyl cyanide to 2-phenylethylamine over a Pd/Al₂O₃ catalyst promoted by synergistic effects of CO₂ and water