Novel Synthetic Methodologies. Part 139. A Rapid, High-Yielding, and Efficient Friedlander Synthesis of Quinolines Catalyzed by 2,4,6-Trichloro-1,3,5-triazine.

ChemInform ◽  
2007 ◽  
Vol 38 (45) ◽  
Author(s):  
Biswanath Das ◽  
Kongara Damodar ◽  
Nikhil Chowdhury ◽  
Kanaparthy Suneel
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.


Author(s):  
Maryam Aisyah Abdullah ◽  
Siti Munirah Mohd Faudzi ◽  
Nadiah Mad Nasir

Abstract:: Medicinal chemists have continuously shown interest in new curcuminoid derivatives, the diarylpentadienones, owing to their enhanced stability feature and easy preparation using a one-pot synthesis. Thus far, methods such as Claisen-Schmidt condensation and Julia-Kocienski olefination have been utilised for the synthesis of these compounds. Diarylpentadienones possess a high potential as a chemical source for designing and developing new and effective drugs for the treatment of diseases, including inflammation, cancer, and malaria. In brief, this review article focuses on the broad pharmacological applications and the summary of the structure-activity relationship of molecules which can be employed to further explore the structure of diarylpentadienone. The current methodological developments towards the synthesis of diarylpentadienones are also discussed.


2018 ◽  
Vol 15 (8) ◽  
pp. 1109-1123
Author(s):  
Jonas da Silva Santos ◽  
Joel Jones Junior ◽  
Flavia M. da Silva

Background: We present here the synthesis of 1,3-thiazolidin-4-one (1) and its functionalised analogues, such as the classical isosteres, glitazone (1,3-thiazolidine-2,4-dione) (2), rhodanine (2-thioxo-1,3- thiazolidin-4-one) (3) and pseudothiohydantoin (2-imino-1,3-thiazolidin-4-one) (4) started in the midnineteenth century to the present day (1865-2018). Objective: The review focuses on the differences in the representation of the molecular structures discussed here over time since the first discussions about the structural theory by Kekulé, Couper and Butlerov. Moreover, advanced synthesis methodologies have been developed for obtaining these functional group, including green chemistry. We discuss about its structure and stability and we show the great biological potential. Conclusion: The 1,3-thiazolidin-4-one nucleus and functionalised analogues such as glitazones (1,3- thiazolidine-2,4-diones), rhodanines (2-thioxo-1,3-thiazolidin-4-ones) and pseudothiohydantoins (2-imino-1,3- thiazolidine-2-4-ones) have great pharmacological importance, and they are already found in commercial pharmaceuticals. Studies indicate a promising future in the area of medicinal chemistry with potential activities against different diseases. The synthesis of these nuclei started in the mid-nineteenth century (1865), with the first discussions about the structural theory by Kekulé, Couper and Butlerov. The present study has demonstrated the differences in the representations of the molecular structures discussed here over time. Since then, various synthetic methodologies have been developed for obtaining these nuclei, and several studies on their structural and biological properties have been performed. Different studies with regards to the green synthesis of these compounds were also presented here. This is the result of the process of environmental awareness. Additionally, the planet Earth is already showing clear signs of depletion, which is currently decreasing the quality of life.


2018 ◽  
Vol 15 (7) ◽  
pp. 940-971 ◽  
Author(s):  
Navjeet Kaur

Background: Due to significant biological activity associated with N-, O- and S-heterocycles, a number of reports for their synthesis have appeared in recent decades. Traditional approaches require expensive or highly specialized equipment or would be of limited use to the synthetic organic chemist due to their highly inconvenient approaches. This review summarizes the applications of copper catalysts with the emphasis on their synthetic applications for nitrogen bearing polyheterocylces. In summary, this review article describes the synthesis of a number of five-membered poly heterocyclic rings. Objective: Nowadays new approaches that employ atom-economical and efficient pathway have been developed. The researchers are following natural models to design and synthesize heterocycles. The transition metal catalyzed protocols have attracted the attention as compared to other synthetic methodologies because they use easily available substrates to build multiple substituted complicated molecules directly under mild conditions. In organic synthesis, constituted by transition metal catalyzed coupling transformations are one of the most powerful and useful protocols. The N-heterocycles are synthesized by this convenient and useful tool. Conclusion: The efficient and chemoselective synthesis of heterocycles by this technique has appeared as an important tool. This review shows a highly dynamic research field and the employment of copper catalysts in organic synthesis. Several strategies have been pointed out in the past few years, to meet more sustainable, efficient and environmentally benign chemical products and procedures. The catalytic strategies have been the focus of intense research because they avoid the use of toxic reagents. Among these catalytic strategies, highly rewarding and an important method in heterocycles synthesis is metal catalyzed synthesis.


2017 ◽  
Vol 14 (6) ◽  
pp. 883-903 ◽  
Author(s):  
Boppudi Hari Babu ◽  
Gandavaram Syam Prasad ◽  
Chamarthi Naga Raju ◽  
Mandava Venkata Basaveswara Rao

Background: Michaelis–Arbuzov reaction has played a key role for the synthesis of dialkyl or diaryl phosphonates by reacting various alkyl or aryl halides with trialkyl or triaryl phosphite. This reaction is very versatile in the formation of P-C bond from the reaction of aliphatic halides with phosphinites or phosphites to yield phosphonates, phosphinates, phosphine oxides. The Arbuzov reaction developed some methodologies, possible mechanistic pathways, selectivity, potential applications and biologically active various phosphonates. Objective: The synthesis of phosphonates via Michaelis–Arbuzov reaction with many new and fascinating methodologies were developed and disclosed in the literature, and these are explored in this review. Conclusion: This review has discussed past developments and vast potential applications of Arbuzov reaction in the synthesis of organophosphonates. As presented in this review, various synthetic methodologies were developed to prepare a large variety of phosphonates. Improvements in the reaction conditions of Lewis-acid mediated Arbuzov rearrangement as well as the development of MW-assisted Arbuzov rearrangement were discussed. Finally, to achieve high selectivities and yields, fine-tuning of reaction conditions including solvent type, temperature, and optimal reaction times to be considered.


2020 ◽  
Vol 17 (8) ◽  
pp. 922-945
Author(s):  
Andrés-Felipe Villamizar-Mogotocoro ◽  
Andrés-Felipe León-Rojas ◽  
Juan-Manuel Urbina-González

The five-membered oxacyclic system of furan-2(5H)-ones, commonly named as γ- butenolides or appropriately as Δα,β-butenolides, is of high interest since many studies have proven its bioactivity. During the past few years, Δα,β-butenolides have been important synthetic targets, with several reports of new procedures for their construction. A short compendium of the main different synthetic methodologies focused on the Δα,β-butenolide ring formation, along with selected examples of compounds with relevant biological activities of these promising pharmaceutical entities is presented.


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