Selective catalytic Knoevenagel condensation by Ni–SiO2 supported heterogeneous catalysts: An environmentally benign approach

2009 ◽  
Vol 10 (4) ◽  
pp. 365-369 ◽  
Author(s):  
V.S.R. Rajasekhar Pullabhotla ◽  
Ateeq Rahman ◽  
S.B. Jonnalagadda
Keyword(s):  
Heterogeneous Catalysts ◽  
Knoevenagel Condensation ◽  
Environmentally Benign

A review of the recent progress on heterogeneous catalysts for Knoevenagel condensation

2021 ◽  
Vol 50 (13) ◽  
pp. 4445-4469
Author(s):  
Jimmy Nelson Appaturi ◽  
Rajni Ratti ◽  
Bao Lee Phoon ◽  
Samaila Muazu Batagarawa ◽  
Israf Ud Din ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Green Chemistry ◽  
Heterogeneous Catalysts ◽  
Recent Progress ◽  
Knoevenagel Condensation ◽  
Sustainable Production ◽  
Organic Reactions ◽  
Synthetic Organic Chemistry

One of the most crucial attributes of synthetic organic chemistry is to design organic reactions under the facets of green chemistry for the sustainable production of chemicals.

A facile approach to fabricate halloysite/metal nanocomposites with preformed and in situ synthesized metal nanoparticles: a comparative study of their enhanced catalytic activity

2015 ◽  
Vol 44 (19) ◽  
pp. 8906-8916 ◽  
Author(s):  
Sankar Das ◽  
Subhra Jana
Keyword(s):  
Catalytic Activity ◽  
Comparative Study ◽  
Metal Nanoparticles ◽  
Heterogeneous Catalysts ◽  
Cost Effective ◽  
Environmentally Benign ◽  
Metal Nanocomposites

Halloysite/metal nanocomposites have been synthesized through the immobilization of preformed and in situ synthesized metal nanoparticles over halloysite surfaces, which in turn produce efficient, cost-effective, and environmentally benign heterogeneous catalysts.

Environmentally Benign Route for the Synthesis of Polycarbonate Diols (PCDLs)−Calcined MgAl Hydrotalcites as Heterogeneous Catalysts

2008 ◽  
Vol 47 (7) ◽  
pp. 2140-2145 ◽  
Author(s):  
Yue Xia Feng ◽  
Ning Yin ◽  
Qi Feng Li ◽  
Jun Wei Wang ◽  
Mao Qing Kang ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Environmentally Benign

scholarly journals Cu(II) and magnetite nanoparticles decorated melamine-functionalized chitosan: A synergistic multifunctional catalyst for sustainable cascade oxidation of benzyl alcohols/Knoevenagel condensation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Zahra Alirezvani ◽  
Mohammad G. Dekamin ◽  
Ehsan Valiey
Keyword(s):  
Catalytic Activity ◽  
Knoevenagel Condensation ◽  
Ambient Pressure ◽  
Reaction Medium ◽  
Environmentally Benign ◽  
One Pot ◽  
Benzyl Alcohols ◽  
External Magnet ◽  
Multistep Synthesis ◽  
Multifunctional Catalyst

AbstractThe uniform decoration of Cu(II) species and magnetic nanoparticles on the melamine-functionalized chitosan afforded a new supramolecular biopolymeric nanocomposite (Cs-Pr-Me-Cu(II)-Fe3O4). The morphology, structure, and catalytic activity of the Cs-Pr-Me-Cu(II)-Fe3O4 nanocomposite have been systematically investigated. It was found that Cs-Pr-Me-Cu(II)-Fe3O4 nanocomposite can smoothly promote environmentally benign oxidation of different benzyl alcohol derivatives by tert-butyl hydroperoxide (TBHP) to their corresponding benzaldehydes and subsequent Knoevenagel condensation with malononitrile, as a multifunctional catalyst. Interestingly, Fe3O4 nanoparticles enhance the catalytic activity of Cu(II) species. The corresponding benzylidenemalononitriles were formed in high to excellent yields at ambient pressure and temperature. The heterogeneous Cs-Pr-Me-Cu(II)-Fe3O4 catalyst was also very stable with almost no leaching of the Cu(II) species into the reaction medium and could be easily recovered by an external magnet. The recycled Cs-Pr-Me-Cu(II)-Fe3O4 was reused at least four times with slight loss of its activity. This is a successful example of the combination of chemo- and bio-drived materials catalysis for mimicing biocatalysis as well as sustainable and one pot multistep synthesis.

Two organic–inorganic hybrid polyoxovanadates as reusable catalysts for Knoevenagel condensation

2019 ◽  
Vol 43 (15) ◽  
pp. 5813-5819 ◽  
Author(s):  
Chunxia Li ◽  
Dandan Zhong ◽  
Xianqiang Huang ◽  
Guodong Shen ◽  
Qiang Li ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Catalytic Properties ◽  
Knoevenagel Condensation ◽  
Inorganic Hybrid

Two novel polyoxovanadates as heterogeneous catalysts have exhibited excellent catalytic properties in the Knoevenagel condensation, especially compound 1's activity is basically maintained after three cycles.

An Efficient and Reusable Multifunctional Composite Magnetic Nanocatalyst for Knoevenagel Condensation

Synlett ◽  
2019 ◽  
Vol 30 (06) ◽  
pp. 699-702 ◽  
Author(s):  
Yu Hu ◽  
Nan Yao ◽  
Jin Tan ◽  
Yang Liu
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Knoevenagel Condensation ◽  
Metal Organic Framework ◽  
Catalytic Performance ◽  
Significant Loss ◽  
Magnetic Nanocatalyst ◽  
Metal Organic ◽  
Nife2o4 Nanoparticles ◽  
Organic Framework

A range of multifunctional magnetic metal–organic framework nanomaterials consisting of various mass ratios of the metal–organic framework MIL-53(Fe) and magnetic SiO2@NiFe2O4 nanoparticles were designed, prepared, characterized, and evaluated as heterogeneous catalysts for the Knoevenagel condensation. The as-fabricated nanomaterials, especially the nanocatalyst MIL-53(Fe)@SiO2@NiFe2O4(1.0), showed good catalytic performance in the Knoevenagel condensation at room temperature as a result of synergistic interaction between the Lewis acid iron sites of MIL-53(Fe) and the active sites of the magnetic SiO2@NiFe2O4 nanoparticles. In addition, the heterogeneous catalyst was readily recovered and a recycling test showed that it could be reused for five times without significant loss of its catalytic activity, making it economical and environmentally friendly.

Biodiesel Production Using Mixed Solid Catalysts

2013 ◽  
Vol 824 ◽  
pp. 451-458
Author(s):  
A.K. Temu
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Biodiesel Production ◽  
Environmentally Benign ◽  
Catalyst Loading ◽  
Yield Data ◽  
Continuous Processes ◽  
Solid Catalysts ◽  
Base Catalysts ◽  
Astm D6751

One of the disadvantages of homogeneous base catalysts in biodiesel production is that they cannot be reused or regenerated because they are consumed in the reaction. Besides, homogeneous catalysed process is not environmentally friendly because a lot of waste water is produced in the separation step. Unlike homogeneous, heterogeneous catalysts are environmentally benign, can be reused and regenerated, and could be operated in continuous processes, thus providing a promising option for biodiesel production. This paper presents catalytic activity of single and mixed solid catalysts in production of biodiesel from palm oil using methanol as well as ethanol at atmospheric pressure. The catalysts used are CaO, K2CO3, Al2O3, and CaO/K2CO3, CaO/Al2O3, K2CO3/Al2O3 mixtures. Results show that methanol is a better reactant with biodiesel yield ranging from 48 to 96.5% while ethanol gives yields ranging from 20 to 95.2%. The yield data for single catalysts range from 20 to 89.2% while that for mixed catalysts range from 52 to 96.5% indicating improvement in the activity by mixing the catalysts. The study also shows that biodiesel yield increases with catalyst loading which emphasizes the need for sufficient number of active sites. The properties of biodiesel produced compares well with ASTM D6751 and EN 14124 biodiesel standards.

scholarly journals Layered double hydroxide anchored ionic liquids as amphiphilic heterogeneous catalysts for the Knoevenagel condensation reaction

2018 ◽  
Vol 47 (9) ◽  
pp. 3059-3067 ◽  
Author(s):  
Tengfei Li ◽  
Wei Zhang ◽  
Wei Chen ◽  
Haralampos N. Miras ◽  
Yu-Fei Song
Keyword(s):  
Heterogeneous Catalysts ◽  
Knoevenagel Condensation ◽  
Condensation Reaction ◽  
Knoevenagel Reaction ◽  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Excellent Activity ◽  
Knoevenagel Condensation Reaction ◽  
Double Hydroxide

In this paper, three solid base catalysts of LDH-IL-Cn (n = 4, 8, 12) were synthesized by adopting an exfoliation/assembly approach. The as-prepared catalyst showed excellent activity and selectivity for the Knoevenagel reaction in aqueous solution.

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