scholarly journals Iridium/Graphene Nanostructured Catalyst for the N-Alkylation of Amines to Synthesize Nitrogen-containing Derivatives and Heterocyclic Compounds

Author(s):  
Tsun-Ren Chen ◽  
Yu-Tung Chen ◽  
Yen-Hsing Lin ◽  
Hao-Chen Wang

A facile iridium/graphene-catalyzed methodology providing an efficient synthetic route for C-N bond formation is reported. This catalyst can directly promote the formation of C-N bonds, without pre-activation steps, and without solvents, alkalis and other additives. This protocol provides a direct N -alkylation of amines using a variety of primary and secondary alcohols with good selectivity and excellent yields. Charmingly, the use of diols resulted in intermolecular cyclization of amines, and such products are privileged structures in biologically active compounds. Two examples illustrate the advantages of this catalyst in organic synthesis: the tandem catalysis to synthesize hydroxyine, and the intermolecular cyclyzation to synthesize cyclizine. Water is the only by-product, which makes this catalytic process sustainable and environmentally friendly.

2021 ◽  
Vol 25 ◽  
Author(s):  
Navjeet Kaur ◽  
Neha Ahlawat ◽  
Yamini Verma ◽  
Pooja Grewal ◽  
Pranshu Bhardwaj ◽  
...  

: Heterocyclic compounds are the largest and most diverse family of organic compounds. Among them, aromatic heterocyclic compounds are the structural motifs found in many biologically active synthetic and natural compounds, agrochemicals, and medicines. Moreover, aromatic heterocyclic compounds are extensively utilized to form dyes and polymeric materials of great importance. In organic synthesis, there are several reports on the uses of aromatic heterocyclic compounds as intermediates. In this review article, we have focused on the synthesis of heterocycles using crown ethers.


2020 ◽  
Author(s):  
Rui Guo ◽  
Xiaotian Qi ◽  
Hengye Xiang ◽  
Paul Geaneoates ◽  
Ruihan Wang ◽  
...  

Vinyl fluorides play an important role in drug development as they serve as bioisosteres for peptide bonds and are found in a range of biologically active molecules. The discovery of safe, general and practical procedures to prepare vinyl fluorides remains an important goal and challenge for synthetic chemistry. Here we introduce an inexpensive and easily-handled reagent and report simple, scalable, and metal-free protocols for the regioselective and stereodivergent hydrofluorination of alkynes to access both the E and Z isomers of vinyl fluorides. These conditions were suitable for a diverse collection of alkynes, including several highly-functionalized pharmaceutical derivatives. Mechanistic and DFT studies support C–F bond formation through a vinyl cation intermediate, with the (E)- and (Z)-hydrofluorination products forming under kinetic and thermodynamic control, respectively.<br>


Author(s):  
Shukla PK ◽  
Singh MP ◽  
Patel R

Indole and its derivatives have engaged a unique place in the chemistry of nitrogen heterocyclic compounds. The recognition of the plant growthhormone, heteroauxin, the significant amino acids, tryptamine & tryptophan and anti-inflammatory drug, indomethacine are the imperativederivatives of indole which have added stimulus to this review work. Isatin (1H-indole-2,3-dione), an indole derivative of plant origin. Althoughit is a naturally occurring compound, but was synthesized by Erdmann and Laurent in 1840 before it was found in nature. Isatin is a versatileprecursor for many biologically active molecules and its diversified nature makes it a versatile substrate for further modifications. It is concernedin many pharmacological activities like anti-malarial, antiviral, anti-allergic, antimicrobial etc; isatin and its derivatives have been also found todemonstrate promising outcomes against various cancer cell lines. This review provides a brief overview on the recent advances and futureperspectives on chemistry and biological aspects of isatin and its derivatives reported in the recent past.


Author(s):  
Harish Rajak ◽  
Murli Dhar Kharya ◽  
Pradeep Mishra

There are vast numbers of pharmacologically active heterocyclic compounds in regular clinical use. The presence of heterocyclic structures in diverse types of compounds is strongly indicative of the profound effects such structure exerts on physiologic activity, and recognition of this is abundantly reflected in efforts to find useful synthetic drugs. The 1,3,4-oxadiazole nucleus has emerged as one of the potential pharmacophore responsible for diverse pharmacological properties. Medical Literature is flooded with reports of a variety of biological activities of 2,5-Disubstituted-1,3,4-oxadiazoles. The present work is an attempt to summarize and enlist the various reports published on biologically active 2,5-disubstituted-1,3,4-oxadiazoles.


2019 ◽  
Vol 26 (23) ◽  
pp. 4323-4354 ◽  
Author(s):  
Ana Cristina Lima Leite ◽  
José Wanderlan Pontes Espíndola ◽  
Marcos Veríssimo de Oliveira Cardoso ◽  
Gevanio Bezerra de Oliveira Filho

Background: Privileged motifs are recurring in a wide range of biologically active compounds that reach different pharmaceutical targets and pathways and could represent a suitable start point to access potential candidates in the neglected diseases field. The current therapies to treat these diseases are based in drugs that lack of the desired effectiveness, affordable methods of synthesis and allow a way to emergence of resistant strains. Due the lack of financial return, only few pharmaceutical companies have been investing in research for new therapeutics for neglected diseases (ND). Methods: Based on the literature search from 2002 to 2016, we discuss how six privileged motifs, focusing phthalimide, isatin, indole, thiosemicarbazone, thiazole, and thiazolidinone are particularly recurrent in compounds active against some of neglected diseases. Results: It was observed that attention was paid particularly for Chagas disease, malaria, tuberculosis, schistosomiasis, leishmaniasis, dengue, African sleeping sickness (Human African Trypanosomiasis - HAT) and toxoplasmosis. It was possible to verify that, among the ND, antitrypanosomal and antiplasmodial activities were between the most searched. Besides, thiosemicarbazone moiety seems to be the most versatile and frequently explored scaffold. As well, phthalimide, isatin, thiazole, and thiazolidone nucleus have been also explored in the ND field. Conclusion: Some described compounds, appear to be promising drug candidates, while others could represent a valuable inspiration in the research for new lead compounds.


2020 ◽  
Vol 26 (41) ◽  
pp. 7337-7371 ◽  
Author(s):  
Maria A. Chiacchio ◽  
Giuseppe Lanza ◽  
Ugo Chiacchio ◽  
Salvatore V. Giofrè ◽  
Roberto Romeo ◽  
...  

: Heterocyclic compounds represent a significant target for anti-cancer research and drug discovery, due to their structural and chemical diversity. Oxazoles, with oxygen and nitrogen atoms present in the core structure, enable various types of interactions with different enzymes and receptors, favoring the discovery of new drugs. Aim of this review is to describe the most recent reports on the use of oxazole-based compounds in anticancer research, with reference to the newly discovered iso/oxazole-based drugs, to their synthesis and to the evaluation of the most biologically active derivatives. The corresponding dehydrogenated derivatives, i.e. iso/oxazolines and iso/oxazolidines, are also reported.


2019 ◽  
Vol 23 (11) ◽  
pp. 1214-1238 ◽  
Author(s):  
Navjeet Kaur ◽  
Pranshu Bhardwaj ◽  
Meenu Devi ◽  
Yamini Verma ◽  
Neha Ahlawat ◽  
...  

Due to special properties of ILs (Ionic Liquids) like their wide liquid range, good solvating ability, negligible vapour pressure, non-inflammability, environment friendly medium, high thermal stability, easy recycling and rate promoters etc. they are used in organic synthesis. The investigation for the replacement of organic solvents in organic synthesis is a growing area of interest due to increasing environmental issues. Therefore, ionic liquids have attracted the attention of chemists and act as a catalyst and reaction medium in organic reaction with high activity. There is no doubt that ionic liquids have become a major subject of study for modern chemistry. In comparison to traditional processes the use of ionic liquids resulted in improved, complimentary or alternative selectivities in organic synthesis. The present manuscript reported the synthesis of multiple nitrogen containing five-membered heterocyclic compounds using ionic liquids. This review covered interesting discoveries in the past few years.


2018 ◽  
Vol 15 (2) ◽  
pp. 208-220 ◽  
Author(s):  
Vaibhav Mishra ◽  
Tejpal Singh Chundawat

Background: Substituted piperazine heterocycles are among the most significant structural components of pharmaceuticals. N1/N4 substituted piperazine containing drugs and biological targets are ranked 3rd in the top most frequent nitrogen heterocycles in U.S. FDA approved drugs. The high demand of N1/N4 substituted piperazine containing biologically active compounds and U.S. FDA approved drugs, has prompted the development of Pd catalyzed C-N bond formation reactions for their synthesis. Buchwald-Hartwig reaction is the key tool for the synthesis of these compounds. Objective: This review provides strategies for Pd catalyzed C-N bond formation at N1/N4 of piperazine in the synthesis of drugs and biological targets with diverse use of catalyst-ligand system and reaction parameters. Conclusion: It is clear from the review that a vast amount of work has been done in the synthesis of N1/N4 substituted piperazine containing targets under the Pd catalyzed Buchwald-Hartwig amination of aryl halides by using different catalyst-ligand systems. These methods have become increasingly versatile as a result of innovation in catalyst design and improvements in reaction conditions. This review gives an overview of recent utilization of Buchwald-Hartwig amination reaction in drug/target synthesis.


2014 ◽  
Vol 11 (4) ◽  
pp. 592-604 ◽  
Author(s):  
Natalia Lukasik ◽  
Ewa Wagner-Wysiecka

2019 ◽  
Vol 16 (6) ◽  
pp. 527-543 ◽  
Author(s):  
Pedro M.E. Mancini ◽  
Carla M. Ormachea ◽  
María N. Kneeteman

During the last twenty years, our research group has been working with aromatic nitrosubstituted compounds acting as electrophiles in Polar Diels-Alder (P-DA) reactions with different dienes of diverse nucleophilicity. In this type of reaction, after the cycloaddition reaction, the nitrated compounds obtained as the [4+2] cycloadducts suffer cis-extrusion with the loss of nitrous acid and a subsequent aromatization. In this form, the reaction results are irreversible. On the other hand, the microwave-assisted controlled heating become a powerful tool in organic synthesis as it makes the reaction mixture undergo heating by a combination of thermal effects, dipolar polarization and ionic conduction. As the Diels-Alder (D-A) reaction is one of the most important process in organic synthesis, the microwave (MW) irradiation was applied instead of conventional heating, and this resulted in better yields and shorter reaction times. Several substituted heterocyclic compounds were used as electrophiles and different dienes as nucleophiles. Two experimental situations are involved: one in the presence of Protic Ionic Liquids (PILs) as solvent and the other under solvent-free conditions. The analysis is based on experimental data and theoretical calculations.


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