Magnetite (Ferrites)-Supported Nano-Catalysts: Sustainable Applications in Organic Transformations

Author(s):  
Anuj K. Rathi ◽  
Radek Zboril ◽  
Rajender S. Varma ◽  
Manoj B. Gawande
2019 ◽  
Author(s):  
Meifeng Wang ◽  
Gan Zhu ◽  
Yiqun Li ◽  
Liuqun Gu

Arylboronic acids were widely used as efficient catalysts in direct amide formation and other organic transformations. Surprisingly, reports on their use as catalysts in carbohydrates synthesis are very rare even though boron acid-diol complexation was extensively investigated in molecular recognition for saccharides and so on. Here we developed an efficient arylboronic acids catalyzed dimerization of glucosamines forming deoxyfructosazine which is important compound in pharmaceutical and food industries, against a commonly held belief that excess amount of phenyl boronic acid (or boric acid) is a must. A catalytic mechanism was also proposed and arylboronic acids instead of their boronates was identified as catalysts.


2020 ◽  
Vol 24 ◽  
Author(s):  
Ghodsi Mohammadi Ziarani ◽  
Shima Roshankar ◽  
Fatemeh Mohajer ◽  
Alireza Badiei

Abstract:: Mesoporous silica nanomaterials provide an extraordinary advantage for making new and superior heterogeneous catalysts because of their surface silanol groups. The functionalized mesoporous SBA-15, such as acidic, basic, BrÖnsted, lewis acid, and chiral catalysts, are used for a wide range of organic synthesis. The importance of the chiral ligands, which were immobilized on the SBA-15, was mentioned in this review to achieve chiral products as valuable target molecules. Herein, their synthesis and application in different organic transformations are reviewed from 2016 till date 2020.


2020 ◽  
Vol 24 (14) ◽  
pp. 1610-1642 ◽  
Author(s):  
Ahmed El-Mekabaty ◽  
Hassan A. Etman ◽  
Ahmed Mosbah ◽  
Ahmed A. Fadda

Barbituric, thiobarbituric acids and their related analogs are reactive synthons for the synthesis of drugs and biologically, and pharmaceutically active pyrimidines. The present review aimed to summarize the recent advances in the synthesis of different alkylsubstituted, fused cycles, spiro-, and binary heterocycles incorporated pyrimidine skeleton based on barbituric derivatives. In this sequence, the eco-friendly techniques under catalytic conditions were used for the diverse types of multicomponent reactions under different conditions for the synthesis of various types of heterocycles. Nano-catalysts are efficient for the synthesis of these compounds in high yields and effective catalyst reusability. The compounds are potent antibacterial, cytotoxic, xanthine oxidase inhibitory activities, and attend as urease inhibitors. The projected mechanisms for the synthesis of pyranopyrimidines, benzochromenopyrimidines, chromeno-pyranopyrimidines, spiroxyindoles, oxospiro-tricyclic furopyrimidines, pyrimidine-based monoand bicyclic pyridines were discussed. The potent and diverse biological activities for instance, antioxidant, antibacterial, cytotoxic, and xanthine oxidase inhibitory activities, as well as urease inhibitors, are specified.


2019 ◽  
Vol 23 (16) ◽  
pp. 1738-1755
Author(s):  
Humaira Y. Gondal ◽  
Zain M. Cheema ◽  
Abdul R. Raza ◽  
Ahmed Abbaskhan ◽  
M. I. Chaudhary

Following numerous applications of Wittig reaction now functionalized phosphonium salts are gaining attention due to their characteristic properties and diverse reactivity. This review is focused on α-alkoxyalkyl triphenylphosphonium salts: an important class of functionalized phosphonium salts. Alkoxymethyltriphenylphosphonium salts are majorly employed in the carbon homologation of carbonyl compounds and preparation of enol ethers. Their methylene insertion strategy is extensively demonstrated in the total synthesis of a wide range of natural products and other important organic molecules. Similarly enol ethers prepared thereof are important precursors for different organic transformations like Diels-Alder reaction, Claisen rearrangement, Coupling reactions, Olefin metathesis and Nazarov cyclization. Reactivity of these α-alkoxyalkylphosphonium salts have also been studied in the nucleophilic substitution reactions. A distinctive application of this class of phosphonium salts was recently reported in the phenylation of carbonyl compounds under very mild conditions. Synthesis of structurally diverse alkoxymethyltriphenylphosphonium salts with variation in alkoxy groups as well as counter anions are reported in literature. Here we present a detailed account of different synthetic methodologies for the preparation of this unique class of quaternary phosphonium salts and their applications in organic synthesis.


2019 ◽  
Vol 23 (12) ◽  
pp. 1284-1306
Author(s):  
Vijai K. Rai ◽  
Fooleswar Verma ◽  
Suhasini Mahata ◽  
Smita R. Bhardiya ◽  
Manorama Singh ◽  
...  

The polymeric graphitic carbon nitride (g-C3N4) has been one of the interesting earth abundant elements. Though g-C3N4 finds application as a photocatalyst, its photocatalytic behaviour is limited because of low efficiency, mainly due to rapid charge recombination. To overcome this problem, several strategies have been developed including doping of metal/non-metal in the cavity of g-C3N4. Moreover, the CoFe2O4 NPs have been used in many organic transformations because of its high surface area and easy separation due to its magnetic nature. This review describes the role of cobalt ferrite as magnetic nanoparticles and metal-doped carbon nitride as efficient heterogeneous catalysts for new carbon-carbon and carbon-hetero atom bond formation followed by heterocyclization. Reactions which involved new catalysts for selective activation of readily available substrates has been reported herein. Since nanoparticles enhance the reactivity of catalyst due to higher catalytic area, they have been employed in various reactions such as addition reaction, C-H activation reaction, coupling reaction, cyclo-addition reaction, multi-component reaction, ring-opening reaction, oxidation reaction and reduction reactions etc. The driving force for choosing this topic is based-on huge number of good publications including different types of spinels/metal doped-/graphitic carbon nitride reported in the literature and due to interest of synthetic community in recent years. This review certainly will represent the present status in organic transformation and for exploring further their catalytic efficiency to new organic transformations involving C-H activation reaction through coupling, cyclo-addition, multi-component, ring-opening, oxidation and reduction reactions.


2019 ◽  
Vol 23 (6) ◽  
pp. 643-678
Author(s):  
Lalthazuala Rokhum ◽  
Ghanashyam Bez

Recent years have witnessed a fast development of solid phase synthetic pathways, a variety of solid-supported reagent and its applications in diverse synthetic strategies and pharmaceutical applicability’s. Polymer-supported triphenylphosphine is getting a lot of applications owing to the speed and simplicity in the process. Furthermore, ease of recyclability and reuse of polymer-supported triphenylphosphine added its advantages. This review covers a wide range of useful organic transformations which are accomplished using cross-linked polystyrene-supported triphenylphosphine with the aim of giving renewed interest in the field of organic and medicinal-combinatorial chemistry.


2018 ◽  
Vol 22 (19) ◽  
pp. 1906-1925 ◽  
Author(s):  
Xiao-hua Cai ◽  
Mengzhi Yang ◽  
Bing Xie

2020 ◽  
Vol 16 ◽  
Author(s):  
Meghshyam K. Patil ◽  
Vijay H. Masand ◽  
Atish K. Maldhure

: Schiff bases and their complexes are versatile compounds, which have been synthesized from the condensation of carbonyl compounds with amino compounds and exhibit a broad range of applications in biological, medicinal, catalysis, and industrial purposes. Furthermore, Schiff base-metal complexes have been used as a precursor for the synthesis of different metal oxides, which includes oxides of iron, cobalt, copper, nickel, manganese, vanadium, cadmium, zinc, mercury, etc. and ferrites such as Fe3O4, ZnFe2O4, and ZnCo2O4. These metal oxides have been utilized for several applications, which includes as a catalyst for several organic transformations and for biological activity. This review encompasses different methods of synthesis of metal oxides using Schiff base metal complexes precursor, their characterization, and various applications in detail.


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