Chemistry of heterocyclic compounds at the Institute of Organic Synthesis, Latvian Academy of Sciences

1991 ◽  
Vol 27 (12) ◽  
pp. 1269-1271
Author(s):  
�. Lukevits
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.


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.


1987 ◽  
Vol 35 (5) ◽  
pp. 761-768 ◽  
Author(s):  
Gaston Vernin ◽  
Cyril Parkanyi ◽  
Rene Barone ◽  
Michel Chanon ◽  
Jacques Metzger

2020 ◽  
pp. 176-189
Author(s):  
Jelena Korolova ◽  
Oksana Kovzele ◽  
Ilze Kacane

The paper presents a comparative analysis of some selected Latvian and Russian paremias, the bulk of which has been collected in the time period since the 1970s till nowadays in the south-eastern part of Latvia – Latgale, and studied in the context of Latvian proverbs included in folklore collections and phraseological dictionaries, as well as the archival materials of the Latvian Academy of Sciences and works by Latvian folklorists. The aim of the study is to analyse prototypical paremias from the Holy Scripture and trace the history of their existence and further development among the Latvians and the Russians in the Latgale region based on the qualitative data analysis. The conducted research allows concluding that similar worldview patterns of the Latvians and the Russians are to be searched for in Christianity. The analysed proverbs testify to the fact that culture is a unifying factor for different ethnic groups living in the same region.


Synthesis ◽  
2018 ◽  
Vol 50 (06) ◽  
pp. 1175-1198 ◽  
Author(s):  
Laurent Commeiras ◽  
Muhammad Idham Darussalam Mardjan ◽  
Jean-Luc Parrain

α,β-Unsaturated γ-hydroxy-γ-butyrolactams are of a great interest due to their presence in designed pharmaceutical molecules and numerous natural products displaying a broad spectrum of biological activities. In addition, these five-membered heterocyclic compounds are also relevant and versatile building blocks in organic synthesis. In this context, strategies for the construction of these scaffolds has triggered considerable attention and this review highlights the progress in the formation of α,β-unsaturated γ-hydroxy-γ-butyrolactams (5-hydroxy-1,5-dihydro-2H-pyrrol-2-ones).1 Introduction2 Intramolecular Routes3 Intermolecular Routes4 Oxidation of Heterocyclic Compounds5 Miscellaneous6 Conclusion


Author(s):  
Oluwaseyi Bukky Ovonramwen ◽  
Bodunde Joseph Owolabi ◽  
Amowie Philip Oviawe

Chalcones are useful intermediates in the synthesis of heterocyclic compound and the unique reagents in organic synthesis. The usual approach to obtain chalcones is through Claisen-Schmidt condensation. Several novel heterocyclic chalcone analogs have emerged. Chalcones are multifunctional molecules that possess promising pharmacological activities. Chalcones are known for anti-cancer, antioxidant, anti-inflammatory, anti-microbial, anti-tubercular, antileishmanial, antimalarial, anthelmintic, osteogenic activities. This review article focuses on recent applications of Claisen-Schmidt condensation reaction employed in the synthesis of chalcone, its transformation to heterocyclic compounds and pharmacological activities.


2019 ◽  
Vol 23 (18) ◽  
pp. 1945-1983
Author(s):  
Ankita Chaudhary

Arylglyoxals are important synthons that have been used in the construction of a diverse spectrum of compounds. The use of multicomponent approaches in organic synthesis due to its environmentally friendly nature is a step forward towards sustainability. This review will offer the reader insightful perspectives on the use of arylglyoxals for the synthesis of various heterocyclic compounds like pyrroles, pyrazoles, furans, imidazoles, indoles, oxazoles, pyridines, quinazolines, pyrans, etc using multicomponent approach.


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