Facile Access to 2-Substituted Benzoxazoles Using Sawdust Supported N-Heterocyclic Carbene-Ni Complex via C-H Activation

2020 ◽  
Vol 17 (6) ◽  
pp. 479-489
Author(s):  
Dolly Kale ◽  
Gajanan Rashinkar ◽  
Audumbar Patil ◽  
Arjun Kumbhar ◽  
Rajashri Salunkhe
Keyword(s):  
Heterogeneous Catalyst ◽  
Nickel Complex ◽  
Boronic Acids ◽  
Significant Loss ◽  
Nickel Acetate ◽  
Covalent Grafting ◽  
The Matrix ◽  
Methyl Imidazole

Sawdust supported N-heterocyclic carbene-nickel complex has been prepared by covalent grafting of 1-methyl imidazole in the matrix of chloropropyl modified sawdust followed by reaction with nickel acetate. The resultant NHC-Ni complex was employed as a heterogeneous catalyst for the synthesis of 2-substituted benzoxazoles from benzoxazole and aryl boronic acids following C-H activation strategy. The recycling experiments showed that the complex could be reused for five consecutive runs without significant loss in the yield of products.

Synthesis of Chalcone Derivatives by Phthalhydrazide-Functionalized TiO2-Coated Nano-Fe3O4 as a New Heterogeneous Catalyst

2020 ◽  
Vol 17 ◽  
Author(s):  
Forough Motamedi Nia ◽  
Mahnaz Farahi ◽  
Bahador Karami ◽  
Raziyeh Keshavarz
Keyword(s):  
Heterogeneous Catalyst ◽  
Significant Loss ◽  
Magnetic Nanocatalyst ◽  
Chalcone Derivatives ◽  
Ft Ir ◽  
Nano Fe3o4

Abstract:: Phthalhydrazide immobilized on TiO2-coated nano Fe3O4 (Fe3O4-P) was synthesized and characterized by FT-IR, XRD, SEM, EDS and VSM analysis. The resulting magnetic nanocatalyst was used as a catalyst for the synthesis of chalcone derivatives which affords the desired products in good to excellent yields. This catalyst can be isolated readily after completion of the reaction by an external magnetite field and reused several times without significant loss of activity.

scholarly journals Development of a Decellularized Porcine Esophageal Matrix for Potential Applications in Cancer Modeling

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1055
Author(s):  
Hersh Chaitin ◽  
Michael L. Lu ◽  
Michael B. Wallace ◽  
Yunqing Kang
Keyword(s):  
Cell Growth ◽  
Lymphatic Vessels ◽  
Significant Loss ◽  
Cancer Cell Growth ◽  
Cell Growth And Migration ◽  
Decellularized Extracellular Matrix ◽  
Cancer Models ◽  
The Matrix ◽  
Potential Applications ◽  
And Migration

Many decellularized extracellular matrix-derived whole organs have been widely used in studies of tissue engineering and cancer models. However, decellularizing porcine esophagus to obtain decellularized esophageal matrix (DEM) for potential biomedical applications has not been widely investigated. In this study a modified decellularization protocol was employed to prepare a porcine esophageal DEM for the study of cancer cell growth. The cellular removal and retention of matrix components in the porcine DEM were fully characterized. The microstructure of the DEM was observed using scanning electronic microscopy. Human esophageal squamous cell carcinoma (ESCC) and human primary esophageal fibroblast cells (FBCs) were seeded in the DEM to observe their growth. Results show that the decellularization process did not cause significant loss of mechanical properties and that blood ducts and lymphatic vessels in the submucosa layer were also preserved. ESCC and FBCs grew on the DEM well and the matrix did not show any toxicity to cells. When FBS and ESCC were cocultured on the matrix, they secreted more periostin, a protein that supports cell adhesion on matrix. This study shows that the modified decellularization protocol can effectively remove the cell materials and maintain the microstructure of the porcine esophageal matrix, which has the potential application of studying cell growth and migration for esophageal cancer models.

Cu-ACP-Am-Fe3O4@SiO2: an efficient and recyclable heterogeneous catalyst for the Chan–Lam coupling reaction of boronic acids and amines

2020 ◽  
Vol 151 (1) ◽  
pp. 87-92 ◽  
Author(s):  
Sandip P. Vibhute ◽  
Pradeep M. Mhaldar ◽  
Dipak S. Gaikwad ◽  
Rajendra V. Shejwal ◽  
Dattaprasad M. Pore
Keyword(s):  
Heterogeneous Catalyst ◽  
Coupling Reaction ◽  
Boronic Acids ◽  
Recyclable Heterogeneous Catalyst

scholarly journals Correction: Copper immobilized at a covalent organic framework: an efficient and recyclable heterogeneous catalyst for the Chan–Lam coupling reaction of aryl boronic acids and amines

2019 ◽  
Vol 21 (3) ◽  
pp. 712-712
Author(s):  
Yi Han ◽  
Mo Zhang ◽  
Ya-Qing Zhang ◽  
Zhan-Hui Zhang
Keyword(s):  
Heterogeneous Catalyst ◽  
Coupling Reaction ◽  
Boronic Acids ◽  
Covalent Organic Framework ◽  
Recyclable Heterogeneous Catalyst ◽  
Organic Framework

Correction for ‘Copper immobilized at a covalent organic framework: an efficient and recyclable heterogeneous catalyst for the Chan–Lam coupling reaction of aryl boronic acids and amines’ by Yi Han et al., Green Chem., 2018, 20, 4891–4900.

scholarly journals Switchable Access to Amines and Imines from Reductive Coupling of Nitroarenes with Alcohols Catalyzed by Biomass-Derived Cobalt Nanoparticles

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 116 ◽  
Author(s):  
Tao Song ◽  
Yanan Duan ◽  
Xiufang Chen ◽  
Yong Yang
Keyword(s):  
Heterogeneous Catalyst ◽  
Reaction System ◽  
Reaction Medium ◽  
Cobalt Nanoparticles ◽  
Significant Loss ◽  
Reductive Coupling ◽  
Hierarchical Porous ◽  
Borrowing Hydrogen ◽  
High Yields ◽  
First Time

Cobalt nanoparticles modified with N-doped hierarchical porous carbon derived from biomass are found to be a highly efficient, reusable heterogeneous catalyst for the coupling of nitroarenes with alcohols, selectively affording imines and amines via the borrowing hydrogen strategy for the first time. The product selectivity between imine and amine may be precisely tuned by simple alteration of the reaction conditions without changing the catalyst in one reaction system. In this study, a broad set of complex imines and amines was successfully synthesized in good to high yields with various functional groups tolerated for both nitroarenes and alcohols, highlighting the potentially practical utility of the protocol. This heterogeneous catalyst can be easily removed from the reaction medium by external magnet and can be reused at least four times without significant loss in activity and selectivity.

Cu(ii) anchored nitrogen-rich covalent imine network (CuII-CIN-1): an efficient and recyclable heterogeneous catalyst for the synthesis of organoselenides from aryl boronic acids in a green solvent

RSC Advances ◽  
2014 ◽  
Vol 4 (86) ◽  
pp. 46075-46083 ◽  
Author(s):  
Susmita Roy ◽  
Tanmay Chatterjee ◽  
Biplab Banerjee ◽  
Noor Salam ◽  
Asim Bhaumik ◽  
...  
Keyword(s):  
Heterogeneous Catalyst ◽  
Cross Coupling ◽  
Boronic Acids ◽  
Coupling Reactions ◽  
Green Solvent ◽  
Cross Coupling Reactions ◽  
Recyclable Heterogeneous Catalyst

A Cu(ii)-grafted covalent imine framework material has been designed, which catalyzes the C–Se cross-coupling reactions to obtain a library of organoselenides.

scholarly journals Co-N-Si/AC Catalyst for Aerobic Oxidation of Benzyl Alcohols to Esters under Mild Conditions

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6792
Author(s):  
Changjian Zhou ◽  
Rong Sun ◽  
Yuting Zhang ◽  
Biao Xiong ◽  
Hui Dai ◽  
...  
Keyword(s):  
Heterogeneous Catalyst ◽  
Active Sites ◽  
Aerobic Oxidation ◽  
Significant Loss ◽  
Ambient Conditions ◽  
Benzyl Alcohols ◽  
Oxidative Esterification ◽  
Product Yields ◽  
Mild Conditions ◽  
Earth Abundant

A stable, earth-abundant, reusable cobalt-based heterogeneous catalyst is developed for the oxidative esterification of alcohols under ambient conditions, featuring broad substrate scope, providing good to excellent product yields. This protocol enables easy recyclability of the catalyst, measured up to five times without significant loss of efficiency. The active sites of Co-N-Si/AC are proposed to be Co-N species.

scholarly journals Evolution of Microstructure and Mechanical Properties of LM25–HEA Composite Processed through Stir Casting with a Bottom Pouring System

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 230
Author(s):  
Mekala Chinababu ◽  
Nandivelegu Naga Krishna ◽  
Katakam Sivaprasad ◽  
Konda Gokuldoss Prashanth ◽  
Eluri Bhaskara Rao
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Matrix ◽  
Stir Casting ◽  
Significant Loss ◽  
Aluminum Matrix Composites ◽  
High Entropy Alloy ◽  
High Entropy ◽  
The Matrix

Aluminum matrix composites reinforced by CoCrFeMnNi high entropy alloy (HEA) particulates were fabricated using the stir casting process. The as-cast specimens were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The results indicated that flake-like silicon particles and HEA particles were distributed uniformly in the aluminum matrix. TEM micrographs revealed the presence of both the matrix and reinforcement phases, and no intermetallic phases were formed at the interface of the matrix and reinforcement phases. The mechanical properties of hardness and tensile strength increased with an increase in the HEA content. The Al 6063–5 wt.% HEA composite had a ultimate tensile strength (UTS) of approximately 197 MPa with a reasonable ductility (around 4.05%). The LM25–5 wt.% HEA composite had a UTS of approximately 195 Mpa. However, the percent elongation decreased to roughly 3.80%. When the reinforcement content increased to 10 wt.% in the LM25 composite, the UTS reached 210 MPpa, and the elongation was confined to roughly 3.40%. The fracture morphology changed from dimple structures to cleavage planes on the fracture surface with HEA weight percentage enhancement. The LM25 alloy reinforced with HEA particles showed enhanced mechanical strength without a significant loss of ductility; this composite may find application in marine and ship building industries.

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