scholarly journals Phenazine Radical Cations as Efficient Homogeneous and Heterogeneous Catalysts for the Cross‐Dehydrogenative Aza‐ Henry Reaction

2020 ◽  
Vol 103 (12) ◽  
Author(s):  
Felix Unglaube ◽  
Paul Hünemörder ◽  
Xuewen Guo ◽  
Zixu Chen ◽  
Dengxu Wang ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Radical Cations ◽  
Henry Reaction ◽  
The Cross

Heterogeneous System in Organic Synthesis: A Review

2020 ◽  
Vol 17 (6) ◽  
pp. 740-753
Author(s):  
Bishwajit Changmai ◽  
Gunindra Pathak ◽  
Jasha Momo H. Anal ◽  
Lalthazuala Rokhum
Keyword(s):  
Organic Synthesis ◽  
Heterogeneous System ◽  
Heterogeneous Catalysts ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Environmentally Friendly ◽  
Henry Reaction ◽  
Phase Synthesis ◽  
Recent Developments ◽  
Recovery And Reuse

Due to its inherent advantages such as easy recovery and reuse of the catalysts/ reagents, and environmentally friendly nature, the heterogeneous system has gain popularity in the realm of organic synthesis. In recent years, several chemically or biologically potent molecules are achieved through heterogeneous synthesis strategies. By recalling some of the classical fundamentals of the heterogeneous system in important organic synthesis, this mini-review outlines the recent developments in the applications heterogeneous catalysts and reagents; particularly in the solid phase synthesis, esterification and transesterification reactions to produce biodiesel, and Henry reaction.

Zinc amidoisophthalate complexes and their catalytic application in the diastereoselective Henry reaction

2015 ◽  
Vol 39 (4) ◽  
pp. 3004-3014 ◽  
Author(s):  
Anirban Karmakar ◽  
M. Fátima C. Guedes da Silva ◽  
Susanta Hazra ◽  
Armando J. L. Pombeiro
Keyword(s):  
Heterogeneous Catalysts ◽  
Henry Reaction ◽  
Catalytic Application

5-Propionamidoisophthalic acid and 5-benzamidoisophthalic acid are used to synthesize new zinc(ii) complexes which act as heterogeneous catalysts for the diastereoselective nitroaldol (Henry) reaction.

scholarly journals Metal-Organic Frameworks as Versatile Heterogeneous Solid Catalysts for Henry Reactions

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1445
Author(s):  
Francisco G. Cirujano ◽  
Rafael Luque ◽  
Amarajothi Dhakshinamoorthy
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Final Section ◽  
Metal Organic Frameworks ◽  
Henry Reaction ◽  
Solid Catalysts ◽  
Wide Range ◽  
Metal Organic ◽  
Materials Used ◽  
Heterogeneous Solid

Metal–organic frameworks (MOFs) have become one of the versatile solid materials used for a wide range of applications, such as gas storage, gas separation, proton conductivity, sensors and catalysis. Among these fields, one of the more well-studied areas is the use of MOFs as heterogeneous catalysts for a broad range of organic reactions. In the present review, the employment of MOFs as solid catalysts for the Henry reaction is discussed, and the available literature data from the last decade are grouped. The review is organized with a brief introduction of the importance of Henry reactions and structural properties of MOFs that are suitable for catalysis. The second part of the review discusses the use of MOFs as solid catalysts for the Henry reaction involving metal nodes as active sites, while the third section provides data utilizing basic sites (primary amine, secondary amine, amides and urea-donating sites). While commenting on the catalytic results in these two sections, the advantage of MOFs over other solid catalysts is compared in terms of activity by providing turnover number (TON) values and the structural stability of MOFs during the course of the reaction. The final section provides our views on further directions in this field.

Nanoporous lanthanide metal–organic frameworks as efficient heterogeneous catalysts for the Henry reaction

CrystEngComm ◽  
2016 ◽  
Vol 18 (8) ◽  
pp. 1337-1349 ◽  
Author(s):  
Anirban Karmakar ◽  
Susanta Hazra ◽  
M. Fátima C. Guedes da Silva ◽  
Anup Paul ◽  
Armando J. L. Pombeiro
Keyword(s):  
Heterogeneous Catalysts ◽  
Metal Organic Frameworks ◽  
Henry Reaction ◽  
Metal Organic ◽  
Lanthanide Metal

Zinc metal–organic frameworks: efficient catalysts for the diastereoselective Henry reaction and transesterification

2014 ◽  
Vol 43 (21) ◽  
pp. 7795-7810 ◽  
Author(s):  
Anirban Karmakar ◽  
M. Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro
Keyword(s):  
Heterogeneous Catalysts ◽  
Metal Organic Frameworks ◽  
Henry Reaction ◽  
Zinc Metal ◽  
Metal Organic

Three new amidoterephthalate ligands are utilized to synthesize three new zinc(ii) metal–organic frameworks which act as heterogeneous catalysts for the diastereoselective nitroaldol (Henry) and transesterification reactions.

Cu(II) homogeneous and heterogeneous catalysts for the asymmetric Henry reaction

2010 ◽  
Vol 325 (1-2) ◽  
pp. 8-14 ◽  
Author(s):  
Matthew D. Jones ◽  
Christine J. Cooper ◽  
Mary F. Mahon ◽  
Paul. R. Raithby ◽  
David Apperley ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Henry Reaction

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Structures Resembling Striated Rootlets in Oocytes

1972 ◽  
Vol 30 ◽  
pp. 124-125
Author(s):  
Valerie V. Ernst
Keyword(s):  
Golgi Complex ◽  
Fibrous Structure ◽  
Oocyte Development ◽  
The Cross

During the earliest stage of oocyte development in the limpet, Acmea scutum, Golgi complexes are small, few and randomly dispersed in the cytoplasm. As growth proceeds, the Golgi complexes increase in size and number and migrate to the periphery of the cell. At this time, fibrous structures resembling striated rootlets occur associated with the Golgi complexes. Only one fibrous structure appears to be associated with a Golgi complex.The fibers are periodically cross banded with an average of 4 dense fibrils and 6 lighter fibrils per period (Fig. 1). The cross fibrils have a center to center spacing of about 7 run which appears to be the same as that of the striated rootlets of the gill cilia in this animal.

Energy Distribution in Electron Beams

1972 ◽  
Vol 30 ◽  
pp. 568-569
Author(s):  
Tamotsu Ohno
Keyword(s):  
Electron Beam ◽  
Energy Distribution ◽  
Cross Section ◽  
Integral Curve ◽  
Electron Beams ◽  
Electron Gun ◽  
Angular Divergence ◽  
Apparent Increase ◽  
Integral Width ◽  
The Cross

The energy distribution in an electron; beam from an electron gun provided with a biased Wehnelt cylinder was measured by a retarding potential analyser. All the measurements were carried out with a beam of small angular divergence (<3xl0-4 rad) to eliminate the apparent increase of energy width as pointed out by Ichinokawa.The cross section of the beam from a gun with a tungsten hairpin cathode varies as shown in Fig.1a with the bias voltage Vg. The central part of the beam was analysed. An example of the integral curve as well as the energy spectrum is shown in Fig.2. The integral width of the spectrum ΔEi varies with Vg as shown in Fig.1b The width ΔEi is smaller than the Maxwellian width near the cut-off. As |Vg| is decreased, ΔEi increases beyond the Maxwellian width, reaches a maximum and then decreases. Note that the cross section of the beam enlarges with decreasing |Vg|.

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