Hydrogenation of Quinoline by Rhodium Catalysts Modified with the Tripodal Polyphosphine Ligand MeC(CH2PPh2)3

Bianchini, Claudio; Barbaro, Pierluigi; Macchi, Michela; Meli, Andrea; Vizza, Francesco

doi:10.1002/1522-2675(20011017)84:10<2895::aid-hlca2895>3.0.co;2-0

Cited by 47 publications

(15 citation statements)

References 14 publications

(26 reference statements)

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“…Information on the activity of many organometallics for HDN can be found in the reviews published by Weller et al (15) and Kabe et al (14). For example, in the case of Q, a high HYD rate to give THQ was observed, whereas the HYD of the attached carbocyclic ring was negligible (415). The attractiveness of these catalysts is in their ability to hydrogenate the N-ring at a near atmospheric pressure below 300 K (414).…”

Section: Vi4 Organometallic Catalystsmentioning

confidence: 99%

Hydrodenitrogenation of Petroleum

Furimsky¹,

2005

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A high level of hydrodenitrogenation (HDN) is required to achieve a desirable conversion of other hydroprocessing reactions. This results from a strong adsorption of nitrogen-containing compounds on catalytic sites that slows down the hydrogen activation process and hinders the adsorption of other reactants. Studies on model compounds and real feeds indicate that less than 50 ppm of nitrogen in the feed can poison catalytic sites. Kinetic studies determined adsorption constants of various nitrogen-containing compounds and concluded that at least four different catalytic sites are required to interpret experimental observations in contrast with a dual site site ffi concept, which only considered two sites. The advancements in experimental techniques allowed identification of products formed during very early stages of hydrodenitrogenation. These results confirmed that the removal of the amino group from saturated amines, as the last step in hydrodenitrogenation, is governed by the type of carbon to which the amino group is attached rather than the number of hydrogen atoms attached to carbon in a and b position to nitrogen Performance of conventional Co(Ni)Mo(W)/Al 2 O 3 catalysts during hydrodenitrogenation was enhanced by combination with various additives and by replacing the traditionally used g-Al 2 O 3 support with novel supports. Catalytic functionalities could be modified by using different precursors of active metals and varying conditions during preparation. Progress has been made in the development of catalysts possessing a high selectivity for hydrodenitrogenation. In this case, the nonconventional catalysts based on the carbides and nitrides of transition metals exhibited high activity and selectivity. Noble metal sulfides alone or supported on different supports were active for HDN as well. Feedstocks used for catalyst evaluation included model compounds and mixtures of model compounds as well as real feeds. The challenges in the development of catalysts for hydrodenitrogenation of heavy feeds containing asphaltenes and metals have been identified.In general, compared to Q, conversions were little affected by a methyl (Me) on the aromatic ring, while being lower for Me on the N-ring, except for 2-MeQ. It is evident that Me substitution in the 2-position had little effect on HDN over the NiMoP/Al 2 O 3 catalyst, whereas it actually enhanced the HDN rate over the CoMo/Al 2 O 3 catalyst. For both catalysts the HDN rate was suppressed in 6-MeQ and particularly in 3-MeQ and 4-MeQ. The distribution of N-containing intermediates was influenced by the ring substitution and the type of catalyst. This suggests that several factors influence the overall HDN mechanism of Qs. This should be kept in mind while analyzing differences in the networks proposed by different authors.The preceding discussion on the HDN of Q mostly referred to conventional catalysts. A number of studies on the HDN of Q were conducted over unconventional catalysts. For example, 3-and 4-MeQs were more reactive than Q over the unsupported Zr,...

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Section: Vi4 Organometallic Catalystsmentioning

confidence: 99%

Hydrodenitrogenation of Petroleum

Furimsky¹,

2005

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“…A much more complex kinetic law has been reported by Bianchini and coworkers for the hydrogenation of quinoline catalyzed by the Rh I complex [Rh(DMAD)(triphos)]PF 6 (DMAD = dimethyl acetylenedicarboxylate) [74,75]. The rate was first order with respect to both H 2 in the pressure range from 4 to 30 bar, and in the catalyst concentration range from 36 to 110 mM, while the hydrogenation rate showed an inverse dependence with respect to quinoline concentration.…”

Section: N-heteroaromaticsmentioning

confidence: 99%

“…On the basis of the kinetic study, deuterium labeling and high-pressure NMR experiments under catalytic conditions, as well as the identification of catalytically relevant intermediates, a mechanism was proposed (Scheme 6.18) which essentially differs from that proposed by Sánchez-Delgado for the rate-limiting step (i.e., reversible reduction of the C=N bond instead of the irreversible one of the C 3 =C 4 bond). The overall hydrogenation of the C=N bond, which actually disrupts the aromaticity of quinoline, was proposed as the rate-determining step, which was consistent with the fact that 2,3-dihydroquinoline was reduced faster than quinoline, while the lack of deuterium incorporation into the carbocyclic ring of both THQ and quinoline ruled out the formation of g 6 -quinoline or g 6 -THQ intermediates [74,75].…”

Section: N-heteroaromaticsmentioning

confidence: 99%

Hydrogenation of Arenes and Heteroaromatics

Bianchini¹,

Meli²,

Vizza³

2006

The Handbook of Homogeneous Hydrogenation

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“…104 Pyridine can be reduced to piperidine in the presence of the nickel Ziegler catalyst, 111 2 ]H 2 (PPh 3 ) 2 } − amongst other ruthenium complexes to give the products where the heterocycle is reduced but benzene nuclei are not. 120,[150][151][152][153] For the reduction of quinolone, the cationic rhodium complex [Rh(PPh 3 ) 2 (COD)] + gave the most active catalytic system. 154 Sulfur heteroaromatics, such as thiophene and benzothiophenes, can be reduced by a number of homogeneous catalytic systems including [RuCl 2 (PPh 3 ) 3 ], 154 150,159,160 Many of the recent catalytic systems that have been developed for the hydrogenation of heteroaromatic compounds not only reduce the unsaturation, but also provide asymmetric induction (see Section 8.17.5.2.2.1).…”

Section: Hydrogenations Of Heteroaromatic Compoundsmentioning

confidence: 99%

8.17 Homogeneous Catalytic Hydrogenation of CåC and CåC

Ager¹

2014

Comprehensive Organic Synthesis II

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Hydrogenation of Quinoline by Rhodium Catalysts Modified with the Tripodal Polyphosphine Ligand MeC(CH2PPh2)3

Cited by 47 publications

References 14 publications

Hydrodenitrogenation of Petroleum

Hydrodenitrogenation of Petroleum

Hydrogenation of Arenes and Heteroaromatics

8.17 Homogeneous Catalytic Hydrogenation of CåC and CåC

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