Selective aerobic oxidation of toluene to benzaldehyde catalyzed by covalently anchored N-hydroxyphthalimide and cobaltous ions

Xu, Jinyang; Shi, Gaoquan; Liang, Yuxin; Lu, Qiuting; Ji, Lijun

doi:10.1016/j.mcat.2021.111440

Cited by 11 publications

(7 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The recycled catalyst NHPI-GPTMS-SiO 2 in solvent HFIP has higher catalytic activity than the fresh one probably attributed to the elution of covering materials from the surface of the fresh catalyst. [102] Cobaltous ions are co-immobilized with NHPI by sequential co-precipitation of cobaltous ions followed by covalent anchoring of the intermediate onto NHPI by CÀ OÀ N and SiÀ OÀ Si bonds, using 3-(Glycidoxypropyl) trimethoxysilicane (GPTMS) as a linking molecule. The toluene conversion to benzaldehyde using NHPI-GPTMS-CS catalyst is much higher than in case of using (NHPI-GPTMS-SiO 2 ) and homogeneous cobaltous ions, possibly due to better synergism between N-oxyl radicals and cobaltous ions co-immobilized.…”

Section: Immobilization Of Nhpi Catalystmentioning

confidence: 99%

“…The selectivity of oxidation is improved by using the entirely heterogeneous combination, NHPI‐GPTMS‐SiO 2 /CoO/SiO 2 in solvent hexafluoropropan‐2‐ol (HFIP) compared to combined NHPI‐GPTMS‐SiO 2 /Co(OAc) 2 . The recycled catalyst NHPI‐GPTMS‐SiO 2 in solvent HFIP has higher catalytic activity than the fresh one probably attributed to the elution of covering materials from the surface of the fresh catalyst [102] …”

Section: Nhpi Catalyzed Reactionsmentioning

confidence: 99%

See 1 more Smart Citation

Recent Advances in N‐Hyrdoxypthalimide: As a Free Radical Initiator and its Applications

Bhardwaj

Grover²,

Rasool

et al. 2022

Asian J Org Chem

View full text Add to dashboard Cite

N‐Hydroxypthalimide (NHPI) has become a powerful and versatile organocatalyst, it has been known to catalyze various free‐radical processes leading to the wide range of organic transformations. Primarily, phthalimido‐N‐oxyl (PINO) radical formed from NHPI is highly efficient abstraction species for carrying out radical chain reactions. In this review, we have discussed about the most important and successful reactions from last six years, with their plausible reaction mechanisms. This review broadly covers the type of bond formation such as carbon‐carbon, carbon‐oxygen and carbon‐nitrogen bond formations. We have also highlighted various types of reaction strategies where in combination with divergent reagent systems it helps to construct different types of molecules which further find applications in the synthesis of complex set of biologically active molecule. NHPI catalyzed oxidation reactions of different class of organic compounds are also reviewed.

show abstract

Section: Immobilization Of Nhpi Catalystmentioning

confidence: 99%

Section: Nhpi Catalyzed Reactionsmentioning

confidence: 99%

Recent Advances in N‐Hyrdoxypthalimide: As a Free Radical Initiator and its Applications

Bhardwaj

Grover²,

Rasool

et al. 2022

Asian J Org Chem

View full text Add to dashboard Cite

show abstract

“…Benzaldehyde is a significant organic intermediate, which is widely used in medicine [1], food [2], industry [3] and other fields. However, the benzaldehyde generated from natural pathways is not sufficient to meet market demand, and the product cost of the extraction process is relatively high.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Hydrogenation Property of Methyl Benzoate to Benzyl Aldehyde over Manganese-Based Catalysts with Appropriate Oxygen Vacancies

Gao,

Liu,

et al. 2023

Catalysts

View full text Add to dashboard Cite

The synthesis of benzaldehyde, a compound widely utilized in food, medicine, and cosmetics, was achieved through a one-step catalytic hydrogenation using the cost-effective raw material, methyl benzoate. This process aligns with the principles of atom economy and green production. Despite the development of numerous high-performance catalysts by scholars, the challenge remains in achieving lower reaction temperatures, ideally below 400 °C. In this study, a series of MnOx/γ-Al2O3 catalysts were meticulously prepared using the precipitation-impregnation method. These catalysts featured supports calcined at various temperatures and distinct manganese active components. Characterization techniques such as X-ray diffraction (XRD), N2 physical adsorption, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), H2 temperature programmed reduction (H2-TPR), and NH3 temperature-programmed desorption (NH3-TPD) were employed to analyze the structure and surface properties of the catalysts. Notably, the optimized reaction temperature was found to be 360 °C. The catalyst exhibited the most favorable performance when the calcination temperature of the support was 500 °C and the Mn/Al molar ratio reached 0.18. Under these conditions, the catalyst demonstrated the most suitable oxygen vacancy concentration, yielding impressive results: a conversion rate of 87.90% and a benzaldehyde selectivity of 86.1%. These achievements were attained at 360 °C, atmospheric pressure, a hydrogen to methyl benzoate molar ratio of 40:1, and a Gas Hourly Space Velocity (GHSV) of 800 h−1. This research underscores the potential for optimizing catalysts to enhance the efficiency and sustainability of benzaldehyde synthesis.

show abstract

“…The synthesized catalyst gave toluene conversion of 14.8% at temperature of 90 • C under 1.6 MPa of O 2 . GPTMS was used as the linking molecule to graft NHPI onto the surface of commercial SiO 2 [38,39]. In addition, NHPI was studied in photocatalytic [40,41] and electrocatalytic selective oxidation [42,43], aerobic dehydrogenation of N-heterocycles [44], and intermolecular anti-Markovnikov hydroamination of alkenes [45].…”

Section: Introductionmentioning

confidence: 99%

Selective Aerobic Oxidation of P-Methoxytoluene by Co(II)-Promoted NHPI Incorporated into Cross-Linked Copolymer Structure

et al. 2021

View full text Add to dashboard Cite

A wide series of copolymer materials with various contents of 4-vinyl-diisopropyl-phtalate ester (10–90 mol%), divinylbenzene (1–11 mol%) and styrene, as monomers, were obtained by radical copolymerization. In the last steps of the synthesis, diisopropyl ester functionalities were converted into the form of N-hydroxyphthalimide (NHPI) rings. The obtained materials with the NHPI groups immobilized in the copolymer structure were studied by various physicochemical techniques, including FT-IR, UV-Vis-DR, XPS, elemental analysis, and tested as catalysts in aerobic oxidation of p-methoxytoluene in the presence of Co(II) acetate co-catalyst. Conversion of the aromatic substrate was correlated with the NHPI content and cross-linking degree. The best catalytic performance (conversions higher than 23%) was achieved for the copolymer catalysts containing 60% and 30% of 4-vinyl-diisopropyl-phtalate ester. At too high concentrations of NHPI and DVB, some of the NHPI groups were transformed into inactive (C=O)-N=O species or not available due to embedding inside the copolymer structure. The mechanism of the process involving both NHPI centers, forming phthalimide N-oxyl (PINO) radicals, and Co(II) cations was discussed. Stability of the developed catalysts was also tested. The opening of imide rings took place during the catalytic process, resulting in the formation of carboxyl groups and the release of hydroxylamine molecules. The deactivated catalyst could be easily regenerated by repeating two last steps of closing imide ring.

show abstract

Selective aerobic oxidation of toluene to benzaldehyde catalyzed by covalently anchored N-hydroxyphthalimide and cobaltous ions

Cited by 11 publications

References 38 publications

Recent Advances in N‐Hyrdoxypthalimide: As a Free Radical Initiator and its Applications

Recent Advances in N‐Hyrdoxypthalimide: As a Free Radical Initiator and its Applications

Catalytic Hydrogenation Property of Methyl Benzoate to Benzyl Aldehyde over Manganese-Based Catalysts with Appropriate Oxygen Vacancies

Selective Aerobic Oxidation of P-Methoxytoluene by Co(II)-Promoted NHPI Incorporated into Cross-Linked Copolymer Structure

Contact Info

Product

Resources

About