Journal articles: 'Heterocyclic'

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Luna, Isadora Silva, Rayssa Marques Duarte da Cruz, Ryldene Marques Duarte da Cruz, Rodrigo Santos Aquino de Araújo, and Francisco Jaime Bezerra Mendonça-Junior. "1,4-Dithiane-2,5-diol: A Versatile Synthon for the Synthesis of Sulfur-containing Heterocycles." Current Organic Synthesis 15, no. 8 (December 17, 2018): 1026–42. http://dx.doi.org/10.2174/1570179415666180821154551.

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Background: 1,4-Dithiane-2,5-diol (1,4-DTD) is the stable dimer of α-mercapto acetaldehyde. This commercially available ambidentade compound is characterized as having in its chemical structure one group that acts as an electrophile and another that acts as a nucleophile, this permits its use as versatile and efficient synthon in synthetic heterocycle procedures. Objective: The aim of this review is to present synthetic applications of 1,4-DTD in heterocyclic chemistry and their applicability to the synthesis of bioactive compounds. Conclusion: Gewald reactions to obtain C-4 and C-5 unsubstituted 2-amino-thiophene derivatives; sulfa- Michael/Henry and sulfa-Michael/aldol sequences to obtain polysubstituted tetrahydrothiophenes, and other heterocyclic reactions that allow synthesizing several functionalized sulfur-containing heterocycles such as thiazolidines, oxathiazinoles and thiazoles are presented and discussed. The use of such heterocyclics in subsequent reactions allows obtaining various bioactive compounds including the antiretroviral lamivudine which is one of the examples presented in this review.

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Winne, Johan, Jan Hullaert, Bram Denoo, Mien Christiaens, and Brenda Callebaut. "Heterocycles as Moderators of Allyl Cation Cycloaddition Reactivity." Synlett 28, no. 18 (July 27, 2017): 2345–52. http://dx.doi.org/10.1055/s-0036-1588511.

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For the rapid elaboration of polycarbocyclic scaffolds, prevalent in many important families of terpenoid natural products, allyl cations derived from simple heterocyclic alcohols can be used as versatile reaction partners in both (4+3) and (3+2) cycloaddition pathways. Our recent progress in this area is outlined, pointing towards the untapped potential of heterocycles to act as reagents in novel or known but challenging organic transformations.1 Heterocyclic Reagents2 Cycloadditions and Allyl Cations3 Furfuryl Cations in Cycloadditions4 Heterocycle-Substituted Cations in Cycloadditions5 Mechanistic Considerations6 Conclusions and Outlook

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Andres, C. J., Derek J. Denhart, Milind S. Deshpande, and Kevin W. Gillman. "Recent Advances in the Solid Phase Synthesis of Drug Heterocyclic Small Molecules." Combinatorial Chemistry & High Throughput Screening 2, no. 4 (August 1999): 191–210. http://dx.doi.org/10.2174/1386207302666220204193145.

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Abstract: Because of their synthetic challenge, broad range of physical I chemical properties, and diverse biological activities, heterocycles continue to be of interest to both the academic and industrial chemist. This review covers recent advances in the solid phase synthesis of drug-like heterocyclic small molecules. Syntheses which form the heterocycle on the solid phase are emphasized; syntheses in which a preformed heterocycle is functionalized on the solid support have been omitted. The majority of references are from publication year 1999. This review should be of interest to anyone involved in, or contemplating the solid phase synthesis of small molecule drug-like heterocycles, especially for combinatorial chemistry applications.

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Bhattacharya, Somenath, Soumallya Chakraborty, Rohan Pal, Sourav Saha, Bhaskar Ghosh, Chiranjit Mandal, Dr Amitava Roy, and Dr Arin Bhattacharjee. "A Comprehensive Review on Pyrazole and It’s Pharmacological Properties." International Journal for Research in Applied Science and Engineering Technology 10, no. 9 (September 30, 2022): 1769–74. http://dx.doi.org/10.22214/ijraset.2022.46924.

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Abstract: Heterocyclic chemistry is very important aspects in organic chemistry. Heterocyclic system consists of one or more heteroatoms like nitrogen, oxygen, sulphur, etc with hydrogen atoms. The system can be classified as saturated as well as non saturated system or hydrocarbons. Another classification of this ring system is divided in some categories like three-membered, four-membered, five-membered, six-memebered, seven-membered, fused heterocyclics etc. Some compounds under this cklassification are acidic or basic in nature. Examples of heterocyclic compounds are Pyrole, Furan, Thiophene, Pyridine, Quinoline, Isoquinoline, Indole, Purine, Pyrazole, etc. Pyrazole is very important under this heterocyclic ring sysyem. Pyrazole is five membered heterocyclics. Pyrazole is basic and unsaturated in nature due to presence of double bonds in their ring structure. When two nitrogen atoms are associated with five menbered heterocyclic ring in 1,2 positions called as Pyrazole structure. It is also known as 1,2-diazole. It is present in many drugs as well as organic compounds and Pharmaceutical compounds. The review study shown that the structure, physical and chemical properties, nomenclature, synthetic approaches, biological activities of Pyrazole heterocyclic ring structure

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Yadav, Shailendra, Sushma Singh, and Chitrasen Gupta. "A CONCISE OVERVIEW ON HETEROCYCLIC COMPOUNDS EXHIBITING PESTICIDAL ACTIVITIES." International Journal of Advanced Research 9, no. 08 (August 31, 2021): 989–1004. http://dx.doi.org/10.21474/ijar01/13352.

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Heterocyclic compounds are numerous and diverse group of organic compounds. Heterocycles are abundantly found in nature and express various physiological properties. Heterocycles are intricately linked to all aspects of life. There are many heterocyclic compounds currently known, and the number is constantly rising owing to extensive synthetic development and their applications. Heterocyclic compounds are used significantly in a number of areas, including biochemistry and medicinal chemistry, and some others. They are predominantly synthesized in agrochemical and pharmaceutical industries due to their potential biological activities. This review article focuses on recently synthesized heterocyclic compounds and their different pesticidal activities such as antifungal, antibacterial, antiviral, nematocidal, insecticidal, acaricidal, and herbicidal.

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Palaniappan, Saravana Priya. "Pharmacological Role of Heterocyclic Compounds in the Treatment of Alzheimer’s Disease: A Review." Journal of Phytopharmacology 11, no. 4 (August 15, 2022): 289–94. http://dx.doi.org/10.31254/phyto.2022.11412.

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Alzheimer’s disease (AD) is a multifactorial neurological disease that mainly affects the old age people. Neuropathologically, AD is characterized by low level of acetylcholine, loss of synapses and neurons in certain brain regions, accumulation of extracellular amyloid beta peptide (Aβ) and phosphorylation of intracellular tau protein. Patients with AD are characterized by various symptoms such as memory deficits, depression, cognitive dysfunction and difficult to perform daily activities. Currently available drugs for the treatment of AD are used to treat symptomatic relief at an early stage, however the prolonged usage of the drugs may cause adverse side effects. To overcome this, development of drugs produced from natural products is considered as one of the promising alternatives for the treatment of AD. Among that heterocyclic compound play a major role in the development of therapeutic drugs against various disorders. An organic compound which is cyclic or non-cyclic consists of one or more atoms in their ring structure are known as heterocyclic compounds. These heterocyclic compounds occur both in natural and synthetic form and play a major role in the metabolism of all living cells. Most of the organic compounds used as drugs have a heterocyclic core in their skeleton. Nitrogenous bases such as purines and pyrimidines present in DNA, chlorophyll, vitamins contain heterocycle in their structure. Other compounds containing heterocycles are proline, morphine, furan, vinblastine, cephalosporin, penicillin etc. This review summarizes the nomenclature, classification, and the role of heterocyclic compounds in the treatment of Alzheimer's disease.

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Munzeiwa, Wisdom A., Bernard Omondi, and Vincent O. Nyamori. "Architecture and synthesis of P,N-heterocyclic phosphine ligands." Beilstein Journal of Organic Chemistry 16 (March 12, 2020): 362–83. http://dx.doi.org/10.3762/bjoc.16.35.

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Diverse P,N-phosphine ligands reported to date have performed exceptionally well as auxiliary ligands in organometallic catalysis. Phosphines bearing 2-pyridyl moieties prominently feature in literature as compared to phosphines with five-membered N-heterocycles. This discussion seeks to paint a broad picture and consolidate different synthetic protocols and techniques for N-heterocyclic phosphine motifs. The introduction provides an account of P,N-phosphine ligands, and their structural and coordination benefits from combining heteroatoms with different basicity in one ligand. The body discusses the synthetic protocols which focus on P–C, P–N-bond formation, substrate and nucleophile types and different N-heterocycle construction strategies. Selected references are given in relation to the applications of the ligands.

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Zhu, Yannan, and You Huang. "Organocatalyzed [3+3] Annulations for the Construction of Heterocycles." Synthesis 52, no. 08 (February 5, 2020): 1181–202. http://dx.doi.org/10.1055/s-0039-1690810.

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Six-membered heterocyclic systems are widely distributed in many natural products and pharmaceuticals, and the construction of highly functionalized six-membered heterocyclic compounds is an important topic in modern organic synthesis. Organocatalyzed [3+3] annulations represents an important method for assembling a substantial variety of six-membered cycles that contain one or more heteroatoms. This review describes the development of organocatalyzed [3+3] annulations for the synthesis of six-membered heterocycles, including organocatalysis using secondary amines, tertiary amines, phosphines, chiral phosphoric acids and N-heterocyclic carbenes.1 Introduction2 Secondary Amine Catalyzed [3+3] Annulations2.1 Synthesis of Nitrogen Heterocycles2.2 Synthesis of Oxygen Heterocycles2.3 Synthesis of Sulfur Heterocycles3 Tertiary Amine Catalyzed [3+3] Annulations3.1 Catalysis through Multiple Hydrogen-Bonding Interactions3.2 Catalysis of Tertiary Amines as Lewis Bases4 Phosphine-Catalyzed [3+3] Annulations4.1 Synthesis of Nitrogen Heterocycles4.2 Synthesis of Oxygen Heterocycles4.3 Synthesis of Heterocycles Containing Two or More Heteroatoms5 Chiral Phosphoric Acid Catalyzed [3+3] Annulations5.1 Synthesis of Nitrogen Heterocycles5.2 Synthesis of Heterocycles Containing Two or More Heteroatoms6 N-Heterocyclic Carbene Catalyzed [3+3] Annulations6.1 Synthesis of Nitrogen Heterocycles6.2 Synthesis of Oxygen Heterocycles6.3 Synthesis of Heterocycles Containing Two or More Heteroatoms7 Conclusion and Outlook

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Shaikh, Ansar R., Mazahar Farooqui, R. H. Satpute, and Syed Abed. "Overview on Nitrogen containing compounds and their assessment based on ‘International Regulatory Standards’." Journal of Drug Delivery and Therapeutics 8, no. 6-s (December 21, 2018): 424–28. http://dx.doi.org/10.22270/jddt.v8i6-s.2156.

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Heterocyclic compounds have a role in most fields of sciences such as medicinal chemistry, biochemistry also another area of sciences. More than 90% of new drugscontain heterocycles and the interface between chemistry and biology, at which so much new scientific insight, discovery and application is taking place is crossed by heterocyclic compounds. Compounds derived from heterocyclic rings in pharmacy, medicine, agriculture, plastic, polymer and other fields.Most active heterocycles that have shown considerable biological actions as antifungal, anti-inflammatory, antibacterial, anticonvulsant, antiallergic, herbicidal, anticancer activity. There is always a strong need for new and efficient processes in synthesizing of new Heterocycles.Alum have been used as a novel catalyst in the synthesis of Schiff’s bases. Synthesized Schiff’s bases are free from use of ICH class 1 and Class 2 solvents and also free from structural alerts genotoxic impurities. This review highlights on various aspects of heterocyclic compounds with its biological activity & regulatory assessment based on the ‘International Regulatory Standards’. Keywords: Heterocycles. Nitrogen containing compounds Biological activity, History, Regulatory assessment, International Regulatory Standards

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Ábrányi-Balogh, Péter, Aaron Keeley, György G. Ferenczy, László Petri, Tímea Imre, Katarina Grabrijan, Martina Hrast, et al. "Next-Generation Heterocyclic Electrophiles as Small-Molecule Covalent MurA Inhibitors." Pharmaceuticals 15, no. 12 (November 29, 2022): 1484. http://dx.doi.org/10.3390/ph15121484.

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Heterocyclic electrophiles as small covalent fragments showed promising inhibitory activity on the antibacterial target MurA (UDP-N-acetylglucosamine 1-carboxyvinyltransferase, EC:2.5.1.7). Here, we report the second generation of heterocyclic electrophiles: the quaternized analogue of the heterocyclic covalent fragment library with improved reactivity and MurA inhibitory potency. Quantum chemical reaction barrier calculations, GSH (L-glutathione) reactivity assay, and thrombin counter screen were also used to demonstrate and explain the improved reactivity and selectivity of the N-methylated heterocycles and to compare the two generations of heterocyclic electrophiles.

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Adak, Laksmikanta, and Tubai Ghosh. "Recent Progress in Iron-Catalyzed Reactions Towards the Synthesis of Bioactive Five- and Six-Membered Heterocycles." Current Organic Chemistry 24, no. 22 (December 18, 2020): 2634–64. http://dx.doi.org/10.2174/1385272824999200714102103.

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Heterocyclic compounds are the largely diverse organic molecules and find prevalent applications in the fine chemical industry, medicinal chemistry and agricultural science. They are also among the most commonly bearing frameworks in numerous drugs and pharmaceutical substances. Therefore, the development of convenient, efficient and environmentally benign methods to produce various types of heterocyclic compounds is an attractive area of research. For the synthesis and functionalization of heterocycles, enormous achievements have been attributed over the past decades. Recently, ironcatalyzed reactions have accomplished a noteworthy development in the synthesis of heterocycles. This review highlights some remarkable achievements in the iron-catalyzed synthesis of heterocyclic compounds published in the last five years.

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Lechel, Tilman, and Hans-Ulrich Reissig. "Synthesis of heterocycles via alkoxyallenes." Pure and Applied Chemistry 82, no. 9 (May 31, 2010): 1835–44. http://dx.doi.org/10.1351/pac-con-09-09-06.

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Lithiated alkoxyallenes are very versatile components for the synthesis of heterocycles such as furans, pyrroles, and 1,2-oxazines, easily allowing the preparation of natural products via these heterocyclic intermediates. A surprising three-component synthesis of N-acylated enaminones allowed the synthesis of highly functionalized 4-hydroxypyridines, 5-acetyloxazoles, and pyrimidines. All these heterocyclic products are ready for further functionalizations, in particular for palladium-catalyzed reactions, leading to libraries of new interesting heterocycles.

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Shekarkhand, Marzieh, Karim Zare, Majid Monajjemi, Elham Tazikeh-Lemeski, and Masoumeh Sayadian. "Computational study of heterocyclic anticancer compounds through nbo method." Nexo Revista Científica 35, no. 01 (April 6, 2022): 367–81. http://dx.doi.org/10.5377/nexo.v35i01.13982.

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In the present study NBO method contain the HOMO and the LUMO energies are calculated for 10 different heterocycles anticancer drug using B3LYP/6-31G(d,p). Frontier molecular orbitals (HOMO and LUMO) and Molecular Electrostatic Potential map of the compound was produced by using the π stacking of structures and anticancer activity of molecules. The NBO analysis was suggested that the molecular system contains π- π interaction, strong conjugative interactions and the molecule become more polarized owing to the movement of π-electron cloud from donor to acceptor. NBO, HOMO and LUMO energies, were investigated and Anticancer activity of Aromatic Heterocyclic compounds was investigated by NBO study and result was compared with our previous study about NICS and S-NICS of these 10 anticancer drug. the HOMO/LUMO gap of the heterocycle anticancer drug is significantly different from each other. The NBO method is used in both symmetric and asymmetric molecules and provides accurate information on the aromatics of the compound, especially the heterocyclic rings. It also provides accurate information in protected areas. Molecule 8 has the highest amount of HOMO and therefore aromaticity among the studied compounds which confirms the result of molecular orbital examination.

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Cui, Hai-Lei. "Recent Advances in DMSO-Based Direct Synthesis of Heterocycles." Molecules 27, no. 23 (December 2, 2022): 8480. http://dx.doi.org/10.3390/molecules27238480.

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Besides serving as a low-toxicity, inexpensive and easily accessible solvent, dimethyl sulfoxide (DMSO) has also been extensively used as a versatile reagent for the synthesis of functionalized molecules. Dimethyl sulfoxide can not only be utilized as a carbon source, a sulfur source and an oxygen source, but also be employed as a crucial oxidant enabling various transformations. The past decade has witnessed a large number of impressive achievements on the direct synthesis of heterocycles as well as modifications of heterocyclic compounds by applying DMSO as a reagent. This review summarized the DMSO-based direct heterocycle constructions from 2012 to 2022.

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Olšovská, Jana, Karel Štěrba, Martin Slabý, and Tomáš Vrzal. "Novel method for determination of heterocyclic compounds and their impact in brewing technology." KVASNY PRUMYSL 67, no. 2 (April 15, 2021): 417–27. http://dx.doi.org/10.18832/kp2021.67.417.

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A new simultaneous method for determination of 16 heterocyclic compounds using SPE sample preparation and GC-MS determination was developed regarding increasing interest of the role of sensory active compounds in beer. LiChrolut® EN SPE columns proved to be optimal for both, a mixture of analytes with a different polarity and such complicated matrix as beer. Recoveries of individual analytes are about 100% except for three compounds (2-methylpyridine about 30%, maltol and furaneol about 50%); repeatability, uncertainty and LOQ are satisfactory for the method application. The method was used for monitoring of heterocyclic compounds formation during roasting, mashing, hop boiling and fermentation. To summarize, during roasting of malt, the concentration of oxygen heterocycle compounds (OHC) increases more rapidly in comparison with nitrogen heterocycles compounds (NHC) till a critical point where OHC starts to decrease and NHC starts to be formed sharper (with the exception of 2-acetylpyrrole which is similar to OHC). Finally, the total concentration of NHC during fermentation rapidly decreases whilst the OHC concentration is influenced by many factors, e.g., fermentation conditions and yeast strain.

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Ābele, E., R. Ābele, Ļ. Golomba, J. Višņevska, T. Beresņeva, and K. Rubina. "Oximes of Seven-Membered Heterocyclic Compounds Containing One Heteroatom." Latvian Journal of Chemistry 50, no. 3-4 (January 1, 2011): 205–22. http://dx.doi.org/10.2478/v10161-011-0071-7.

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Oximes of Seven-Membered Heterocyclic Compounds Containing One Heteroatom Literature data on the synthesis and structure of azepane, oxepane and thiepane oximes were reviewed. Synthesis of novel heterocycles from oximes of seven-membered heterocycles containing one heteroatom were described. Biological activity of oximes of seven-membered heterocycles with one heteroatom was also reviewed.

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Ābele, E. "Oximes of Seven-Membered Heterocyclic Compounds Containing Two Heteroatoms." Latvian Journal of Chemistry 51, no. 1-2 (January 1, 2012): 83–92. http://dx.doi.org/10.2478/v10161-012-0005-z.

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Oximes of Seven-Membered Heterocyclic Compounds Containing Two Heteroatoms Literature data concerning the synthesis and structure of diazepane, oxazepane and thiazepane oximes were reviewed. Synthesis of novel heterocycles from the oximes of seven-membered heterocycles containing two heteroatoms was described. Biological activity of oximes of seven-membered heterocycles with two heteroatoms was also reviewed.

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Hoffman, Gavin R., and Allen M. Schoffstall. "Syntheses and Applications of 1,2,3-Triazole-Fused Pyrazines and Pyridazines." Molecules 27, no. 15 (July 22, 2022): 4681. http://dx.doi.org/10.3390/molecules27154681.

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Pyrazines and pyridazines fused to 1,2,3-triazoles comprise a set of heterocycles obtained through a variety of synthetic routes. Two typical modes of constructing these heterocyclic ring systems are cyclizing a heterocyclic diamine with a nitrite or reacting hydrazine hydrate with dicarbonyl 1,2,3-triazoles. Several unique methods are known, particularly for the synthesis of 1,2,3-triazolo[1,5-a]pyrazines and their benzo-fused quinoxaline and quinoxalinone-containing analogs. Recent applications detail the use of these heterocycles in medicinal chemistry (c-Met inhibition or GABAA modulating activity) as fluorescent probes and as structural units of polymers.

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Sparr, Christof, and Christian Fischer. "Configurationally Stable Atropisomeric Acridinium Fluorophores." Synlett 29, no. 16 (August 3, 2018): 2176–80. http://dx.doi.org/10.1055/s-0037-1610233.

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Arylated heterocyclic fluorophores are particularly useful scaffolds for numerous applications, such as bioimaging or synthetic photochemistry. While variation of the substitution pattern at the heterocycle and aryl groups allows dye modulation, the bond rotational barriers are also strongly affected. Unsymmetrically substituted ring systems of rotationally restricted arylated heterocycles therefore lead to configurationally stable atropisomeric fluorophores. Herein, we describe these characteristics by determining the properties and configurational stability of atropisomeric, tri-ortho-substituted naphthyl-acridinium fluorophores. A significant barrier to rotation of >120 kJ mol–1 was measured, which renders these dyes and related compounds distinct atropisomers with stereoisomer-specific properties over a broad temperature range.

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Gorbulenko, Natalia, Tetyana Shokol, and Volodymyr Khilya. "Isoflavonoids Modified with Azole Heterocycles with Three Heteroatoms." French-Ukrainian Journal of Chemistry 10, no. 1 (2022): 101–27. http://dx.doi.org/10.17721/fujcv10i1p101-127.

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Heterocycle modified chromones are attracting increasing attention as novel potential therapeutic agents due to their effective bioactivities and low toxicity. This review describes all strategies and versatile synthons that have been developed for the synthesis of isoflavone heterocyclic analogs containing isolated 5-member heterocyclic rings with three identical or different heteroatoms. Their biological activity is also presented.

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Mohareb, Rafat, and Hanaa Hana. "Synthesis of progesterone heterocyclic derivatives of potential antimicrobial activity." Acta Pharmaceutica 58, no. 1 (March 1, 2008): 29–42. http://dx.doi.org/10.2478/v10007-007-0043-3.

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Synthesis of progesterone heterocyclic derivatives of potential antimicrobial activityThe aim of this work was to synthesize steroidal heterocycles and to elucidate the potential role of these compounds as antimicrobial agents. The synthesis of steroidal heterocycles containing the pyrazole, isoxazole, thiazole, pyrane, pyridine, pyridazine, or benzopyrane ring attached to the pregnene nucleus is reported. Progesterone (1) reacts with dimethyl formamide dimethyl acetal to form enamine2. Heterocyclization of2with hydrazines, hydroxylamine, glycine, ethyl acetoacetate or cyanomethylene afforded novel steroidal heterocyclic derivatives. Thein vitroantimicrobial evaluation showed that all synthesized compounds show activity against the used strains of Gram positive bacteria and fungi.

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Georghiou, Paris E. "Preface." Pure and Applied Chemistry 82, no. 9 (January 1, 2010): iv. http://dx.doi.org/10.1351/pac20108209iv.

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The 22nd International Congress on Heterocyclic Chemistry (ICHC-22) was held 2-7 August 2009 in St. John's, Newfoundland and Labrador, Canada. St. John's, the capital of Canada's youngest Province, Newfoundland and Labrador, is also Canada’s oldest and North America’s most easterly city. The Conference was chaired by Prof. Mohsen Daneshtalab (School of Pharmacy, Memorial University of Newfoundland) and was organized by the School of Pharmacy and the Chemistry Department at Memorial University of Newfoundland.Approximately 260 participants from over 30 different countries attended. The scientific program consisted of 10 plenary lectures, 19 invited lectures, 52 short communications, and 115 posters. Prof. Samuel Danishefsky (Sloan-Kettering Institute for Cancer Research, Columbia University) was honored with the 2009 ISHC Senior Award in Heterocyclic Chemistry, and Prof. John Wood (Colorado State University) was the 2009 Katritzky Junior Award winner. A special symposium entitled "Focus on heterocycles in organic synthesis today and tomorrow" was held during the Congress as a tribute to Prof. Victor Snieckus (Queen's University, Kingston) for his research accomplishments and long-time contribution to the International Society of Heterocyclic Chemistry (ISHC).The five Congress themes were:- New Methods in Heterocyclic Chemistry- Biologically Active Heterocycles (Pharmaceuticals/Agrochemicals)- Heterocyclic Natural Products and their Analogues- Applications of Heterocycles in Organic Synthesis- Heterocycles in Materials ScienceBesides the collection of 9 papers that are based on the plenary and invited lectures included in this issue of Pure and Applied Chemistry, the ICHC-22 Book of Abstracts is available online and can be downloaded for free from http://www.ichc2009.ca/abstract_book.pdf in pdf format.ICHC-23 will be held in Glasgow, Scotland, 31 July to 5 August 2011 with the following five main themes of heterocyclic chemistry: synthetic methodology, natural products and complex molecule synthesis, materials, medicinal chemistry, and nanochemistry. The conference will be chaired by Prof. Colin Suckling (University of Strathclyde).The organizers are grateful to all who contributed to a successful scientific program, especially to the speakers and to our public and private sponsors: City of St. John's, Memorial University of Newfoundland, IUPAC, Thieme, Wiley-Blackwell, Elsevier, Taiho Pharmaceutical Co., ChemRoutres Corporation, and American Diagnostica, Inc.Paris E. GeorghiouConference Editor

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Li, Chongyang, Yongli Huang, Chang Q. Sun, and Lei Zhang. "Acidic Stabilization of the Dual-Aromatic Heterocyclic Anions." Catalysts 11, no. 7 (June 24, 2021): 766. http://dx.doi.org/10.3390/catal11070766.

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Recently, we discovered that the delocalization of nitrogen lone-pair electrons (NLPEs) in five-membered nitrogen heterocycles created a second σ-aromaticity in addition to the prototypical π-aromaticity. Such dual-aromatic compounds, such as the pentazole anion, were proved to have distinct chemistry in comparison to traditional π-aromatics, such as benzene, and were surprisingly unstable, susceptible to electrophilic attack, and relatively difficult to obtain. The dual-aromatics are basic in nature, but prefer not to be protonated when confronting more than three hydronium/ammonium ions, which violates common sense understanding of acid−base neutralization for a reason that is unclear. Here, we carried out 63 test simulations to explore the stability and reactivity of three basic heterocycle anions (pentazole anion N5¯, tetrazole anion N4C1H1¯, and 1,2,4-triazole anion N3C2H2¯) in four types of solvents (acidic ions, H3O+ and NH4+, polar organics, THF, and neutral organics, benzene) with different acidities and concentrations. By quantum mechanical calculations of the electron density, atomistic structure, interatomic interactions, molecular orbital, magnetic shielding, and energetics, we confirmed the presence of dual aromaticity in the heterocyclic anions, and discovered their reactivity to be a competition between their basicity and dual aromaticity. Interestingly, when the acidic ions H3O+/NH4+ are three times more in number than the basic heterocyclic anions, the anions turn to violate acid−base neutralization and remain unprotonated, and the surrounding acidic ions start to show a significant stabilization effect on the studied heterocyclic anions. This work brings new knowledge to nitrogen aromatics and the finding is expected to be adaptable for other pnictogen five-membered ring systems.

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Hershberger, John C. "Recent Advances in Palladium-Catalyzed Oxidative Cyclizations." Current Organic Chemistry 23, no. 9 (July 31, 2019): 1019–44. http://dx.doi.org/10.2174/1385272823666190429155004.

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Heterocycles are very common substructures in a number of pharmaceuticals. Over the past several years, the use of palladium-catalyzed oxidative cyclization for heterocyclic synthesis has become much more prevalent. This review collects recent reports using palladium catalysis to synthesize a wide variety of heterocyclic scaffolds. Many of these reactions use oxygen as the terminal oxidant. Some salient mechanistic features are discussed.

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Zhu, Daqian, Zhouming Wu, Liyun Liang, Yameng Sun, Bingling Luo, Peng Huang, and Shijun Wen. "Heterocyclic iodoniums as versatile synthons to approach diversified polycyclic heteroarenes." RSC Advances 9, no. 57 (2019): 33170–79. http://dx.doi.org/10.1039/c9ra07288h.

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Soni, Vatsala, Meenakshi Sharma, Vandana Singh, Vaishali Soni, and Kishore D. "Comprehensive Study of Biological Aspects of Heteroring Annelated Benzothiazoles." International Journal of Science, Engineering and Management 9, no. 6 (June 13, 2022): 1–6. http://dx.doi.org/10.36647/ijsem/09.06.a001.

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Heterocyclic chemicals are chemical structures which include at least a single carbon molecule plus at least one other element, such as sulphur, oxygen, or nitrogen, within the ring structure. Benzothiazoles are discussed in terms of synthesis methodologies, structural changes, chemical reactivity, and possible pharmaceutical effectiveness. This research relied upon secondary data obtained from the sources. The qualitative method was used to provide a section of such an evaluation which looked flawless and accurate. A handy methodology strategy is used in inquiry research. Heterocyclic compounds have been widely exploited in bioorganic and medical research for medication development. Scientists are interested in such compounds because of their various physicochemical and pharmacological properties. Recognizing heterocycles is advantageous in both industrial and biological processes. Benzothiazole, a molecular heterocyclic structure, is being studied as a candidate for such creation of larger, often medicinal chemicals. It is highly durable due to its aromatic components; however, it has reactive services that offer the synthesis method. The benzothiazole ring becomes an important framework for the production of colours used throughout the identification of lanthanide metal cations in aqueous environments. This identical basic N, S heterocycle, benzothiazoles, seems to be abundant; for example, it is required essential thiamine action (vitamin B1). Thiazole compounds could also be discovered in medications such as Nosiheptide. This chemistry group is used for about simply for antibacterial purposes; its distinctive heteroring linked derivatives have attracted the curiosity of scientists due to their various biological or indeed medicinal properties.

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Huang, Pengfei, Pan Wang, Shengchun Wang, Shan Tang, and Aiwen Lei. "Electrochemical oxidative [4 + 2] annulation of tertiary anilines and alkenes for the synthesis of tetrahydroquinolines." Green Chemistry 20, no. 21 (2018): 4870–74. http://dx.doi.org/10.1039/c8gc02463d.

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Geisenberger, Josef, Jürgen Erbe, Jürgen Heidrich, Ulrich Nagela, and Wolfgang Beck. "Pseudohalogenometallverbindungen, LXV [1] Synthese von Tetrazolen und Triazolen über die 1,3-dipolare Cycloaddition an die Azid-Liganden von polymeren Cobalt(III)-und Palladium(II)-Komplexen. Darstellung und Struktur von 5-TrichlormethyItetrazol / Pseudohalogeno Metal Compounds, LXV [1] Synthesis of Tetrazoles and Triazoles via 1,3-Dipolar Cycloaddition to the Azido Ligands of Polymerie Cobalt(III) and Palladium(II) Complexes. Synthesis and Structure of 5-Trichloromethyltetrazole." Zeitschrift für Naturforschung B 42, no. 1 (January 1, 1987): 55–64. http://dx.doi.org/10.1515/znb-1987-0112.

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Abstract The cycloaddition of nitriles and of dimethylacetylenedicarboxylate to the azide ligand of polymeric Schiff Base cobalt(III) and phosphine palladium(II) complexes gives the corresponding tetrazolate and triazolate complexes from which the heterocycles could be cleaved by hydrogen chloride. Usually the yields are low; if the heterocycle is soluble in ether or sublimable, yields up to 30% have been obtained. Using this method the hitherto unknown 5-trichlormethyltetrazole could be prepared which was characterized by an X-ray structural analysis. Similarly, the cyclo-addition of azido(tetraphenylporphinato)cobalt(III) with nitriles, cyclohexylisocyanide and MeO2CC≡CCO2 Me affords the corresponding complexes with heterocyclic ligands. The prepa-ration of tetraphenylporphyrinato(tricyanmethanido)cobalt(III), (TPP)CoN=CC(CN)2 , is reported.

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29

Gaonkar, Santosh L., Vignesh U. Nagaraj, and Swarnagowri Nayak. "A Review on Current Synthetic Strategies of Oxazines." Mini-Reviews in Organic Chemistry 16, no. 1 (November 19, 2018): 43–58. http://dx.doi.org/10.2174/1570193x15666180531092843.

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In the past three decades, the heterocyclic oxazine cores have been intensely concerned. Oxazine derivatives are promising vital heterocyclic motifs. They are eminent for their synthetic potential and extensive biological properties. Oxazines are versatile intermediates for the synthesis of a variety of heterocycles and bifunctional compounds. Researchers have reported several synthetic approaches for the preparation of oxazines. This review emphasises the recent approaches for the synthesis of oxazine derivatives.

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Boelke, Andreas, Soleicha Sadat, Enno Lork, and Boris J. Nachtsheim. "Pseudocyclic bis-N-heterocycle-stabilized iodanes – synthesis, characterization and applications." Chemical Communications 57, no. 60 (2021): 7434–37. http://dx.doi.org/10.1039/d1cc03097c.

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Stephens, David E., Johant Lakey-Beitia, Jessica E. Burch, Hadi D. Arman, and Oleg V. Larionov. "Mechanistic insights into the potassium tert-butoxide-mediated synthesis of N-heterobiaryls." Chemical Communications 52, no. 64 (2016): 9945–48. http://dx.doi.org/10.1039/c6cc04816a.

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Talbi, Soumaya, Mustapha Dib, Latifa Bouissane, Hafid Abderrafia, Souad Rabi, and Mostafa Khouili. "Recent Progress in the Synthesis of Heterocycles based on 1,3-diketones." Current Organic Synthesis 19, no. 2 (March 2022): 220–45. http://dx.doi.org/10.2174/1570179418666211011141428.

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: N,O-heterocycles containing the dicarbonyl ring play a significant role in heterocyclic and therapeutic chemistry. Since the discovery of 1,3-diketones, numerous research works have been achieved regarding the synthesis and its chemical reactivity. In this review, we have described the most relevant publications involving β-diketone compounds published during the period between 2018 to date. In addition, we include the 1,3-diketones-based heterocyclic compounds prepared by various synthetic methodologies.

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Sharma, Praveen Kumar, Andleeb Amin, and M. Kumar. "Synthetic Methods of Medicinally Important Heterocycles-thiazines: A Review." Open Medicinal Chemistry Journal 14, no. 1 (September 14, 2020): 71–82. http://dx.doi.org/10.2174/1874104502014010071.

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Heterocyclic compounds containing N and S atoms have unique properties so that they can be used as potential reactive materials in pharmacokinetic systems. In medicinal chemistry, the therapeutic applications of nitrogen sulphur heterocycles are well known. Especially, Thiazines attract the attention of chemists due to their great bioactive behavior. The present study is a review of the work carried out by the research community for the synthesis of novel, effective, medicinally important heterocyclic compounds-thiazines.

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Zhang, Ming, Qiuhong Wang, Yiyuan Peng, Zhiyuan Chen, Changfeng Wan, Junmin Chen, Yongli Zhao, Rongli Zhang, and Ai Qin Zhang. "Transition metal-catalyzed sp3 C–H activation and intramolecular C–N coupling to construct nitrogen heterocyclic scaffolds." Chemical Communications 55, no. 87 (2019): 13048–65. http://dx.doi.org/10.1039/c9cc06609h.

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35

Slivka, Mikhailo, and Mikhailo Onysko. "The Use of Electrophilic Cyclization for the Preparation of Condensed Heterocycles." Synthesis 53, no. 19 (May 19, 2021): 3497–512. http://dx.doi.org/10.1055/s-0040-1706036.

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AbstractCondensed heterocycles are well-known for their excellent biological effects and they are undeniably important compounds in organic chemistry. Electrophilic cyclization reactions are widely used for the synthesis of mono-heterocyclic compounds. This review highlights the utility of electrophilic cyclization reactions as an effective generic tool for the synthesis of various condensed heterocycles containing functional groups that are able to undergo further chemical transformations, such as nucleophilic substitution, elimination, re-cyclization, cleavage, etc. This review describes the reactions of unsaturated derivatives of different heterocycles with various electrophilic agents (halogens, arylsulfanyl chlorides, mineral acids) resulting in annulation of an additional partially saturated heterocycle. The electrophilic reaction conditions, plausible mechanisms and the use of such transformations in organic synthesis are also discussed. The review mainly focuses on research published since 2002 in order to establish the current state of the art in this area. 1 Introduction2 Electrophilic Cyclization Pathways Involving a Nitrogen Nucleophilic Center3 Electrophilic Cyclization Pathways Involving a Chalcogen Nucleophilic Center3.1 Sulfur Centers3.2 Oxygen Centers3.3 Selenium Centers4 Strategies and Mechanisms5 Conclusion

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Kerru, Nagaraju, Lalitha Gummidi, Suresh Maddila, Kranthi Kumar Gangu, and Sreekantha B. Jonnalagadda. "A Review on Recent Advances in Nitrogen-Containing Molecules and Their Biological Applications." Molecules 25, no. 8 (April 20, 2020): 1909. http://dx.doi.org/10.3390/molecules25081909.

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The analogs of nitrogen-based heterocycles occupy an exclusive position as a valuable source of therapeutic agents in medicinal chemistry. More than 75% of drugs approved by the FDA and currently available in the market are nitrogen-containing heterocyclic moieties. In the forthcoming decade, a much greater share of new nitrogen-based pharmaceuticals is anticipated. Many new nitrogen-based heterocycles have been designed. The number of novel N-heterocyclic moieties with significant physiological properties and promising applications in medicinal chemistry is ever-growing. In this review, we consolidate the recent advances on novel nitrogen-containing heterocycles and their distinct biological activities, reported over the past one year (2019 to early 2020). This review highlights the trends in the use of nitrogen-based moieties in drug design and the development of different potent and competent candidates against various diseases.

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Kumar, Adarsh, Ankit Kumar Singh, Harshwardhan Singh, Veena Vijayan, Deepak Kumar, Jashwanth Naik, Suresh Thareja, et al. "Nitrogen Containing Heterocycles as Anticancer Agents: A Medicinal Chemistry Perspective." Pharmaceuticals 16, no. 2 (February 14, 2023): 299. http://dx.doi.org/10.3390/ph16020299.

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Cancer is one of the major healthcare challenges across the globe. Several anticancer drugs are available on the market but they either lack specificity or have poor safety, severe side effects, and suffer from resistance. So, there is a dire need to develop safer and target-specific anticancer drugs. More than 85% of all physiologically active pharmaceuticals are heterocycles or contain at least one heteroatom. Nitrogen heterocycles constituting the most common heterocyclic framework. In this study, we have compiled the FDA approved heterocyclic drugs with nitrogen atoms and their pharmacological properties. Moreover, we have reported nitrogen containing heterocycles, including pyrimidine, quinolone, carbazole, pyridine, imidazole, benzimidazole, triazole, β-lactam, indole, pyrazole, quinazoline, quinoxaline, isatin, pyrrolo-benzodiazepines, and pyrido[2,3-d]pyrimidines, which are used in the treatment of different types of cancer, concurrently covering the biochemical mechanisms of action and cellular targets.

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Francke, Robert. "Recent advances in the electrochemical construction of heterocycles." Beilstein Journal of Organic Chemistry 10 (December 3, 2014): 2858–73. http://dx.doi.org/10.3762/bjoc.10.303.

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Due to the fact that the major portion of pharmaceuticals and agrochemicals contains heterocyclic units and since the overall number of commercially used heterocyclic compounds is steadily growing, heterocyclic chemistry remains in the focus of the synthetic community. Enormous efforts have been made in the last decades in order to render the production of such compounds more selective and efficient. However, most of the conventional methods for the construction of heterocyclic cores still involve the use of strong acids or bases, the operation at elevated temperatures and/or the use of expensive catalysts and reagents. In this regard, electrosynthesis can provide a milder and more environmentally benign alternative. In fact, numerous examples for the electrochemical construction of heterocycles have been reported in recent years. These cases demonstrate that ring formation can be achieved efficiently under ambient conditions without the use of additional reagents. In order to account for the recent developments in this field, a selection of representative reactions is presented and discussed in this review.

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Liu, Jia-Chun, Suresh Narva, Kang Zhou, and Wen Zhang. "A Review on the Antitumor Activity of Various Nitrogenous-based Heterocyclic Compounds as NSCLC Inhibitors." Mini-Reviews in Medicinal Chemistry 19, no. 18 (November 29, 2019): 1517–30. http://dx.doi.org/10.2174/1389557519666190312152358.

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At present, cancers have been causing deadly fears to humans and previously unpredictable losses to health. Especially, lung cancer is one of the most common causes of cancer-related mortality accounting for approximately 15% of all cancer cases worldwide. While Non-Small Cell Lung Carcinomas (NSCLCs) makes up to 80% of lung cancer cases. The patient compliance has been weakening because of serious drug resistance and adverse drug effects. Therefore, there is an urgent need for the development of novel structural agents to inhibit NSCLCs. Nitrogen-containing heterocyclic compounds exhibit wide range of biological properties, especially antitumor activity. We reviewed some deadly defects of clinical medicines for the lung cancer therapy and importance of nitrogen based heterocyclic derivatives against NSCLCs. Nitrogen heterocycles exhibit significant antitumor activity against NSCLCs. Nitrogen heterocyclic hybrids could be developed as multi-target-directed NSCLC inhibitors and it is believed that the review is significant for rational designs and new ideas in the development of nitrogen heterocyclic-based drugs.

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Ludwig, Miroslav, Iva Bednářová, and Patrik Pařík. "Effect of Medium on Acid-Catalyzed Decomposition of N-(Phenylazo)-Substituted Nitrogen Heterocycles." Collection of Czechoslovak Chemical Communications 64, no. 10 (1999): 1654–72. http://dx.doi.org/10.1135/cccc19991654.

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Four N-(phenylazo)-substituted saturated nitrogen heterocyclics were synthesized and their structure was confirmed by 1H and 13C NMR spectroscopy. The kinetics of their acid-catalyzed decomposition were studied at various concentrations of the catalyst (pivalic acid) in 40, 30, and 20% (v/v) aqueous ethanol at 25 °C. The values obtained for the observed rate constants were processed by the non-linear regression method according to the suggested kinetic models and by the method of principal component analysis (PCA). The interpretation of the results has shown that the acid-catalyzed decomposition of the heterocyclics under the conditions used proceeds by the mechanism of general acid catalysis, the proton being the dominant catalyst particle of the rate-limiting step. The decrease in the observed rate constant at higher concentrations of the catalyst was explained by the formation of a non-reactive complex composed of the undissociated acid and the respective N-(phenylazo)heterocycle. The effect of medium and steric effect of the heterocyclic moiety on the values of catalytic rate constant are discussed.

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Lakó, Ágnes, László Poppe, and Ricardo Mendonça. "Efficient Synthesis of Pharmaceutically Relevant Prochiral Heterocyclic Aminoketones." Periodica Polytechnica Chemical Engineering 65, no. 2 (January 18, 2021): 177–82. http://dx.doi.org/10.3311/ppch.16489.

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In this work, we report a practical method for alkylation of saturated heterocycles with chloroacetone yielding prochiral heterocyclic ketones, including previously not described molecules. The desired building blocks were obtained with high yields in hydrochloric salt forms, without the need for chromatographic purification.

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42

Wang, Min, Zi-Qiang Rong, and Yu Zhao. "Stereoselective synthesis of ε-lactones or spiro-heterocycles through NHC-catalyzed annulation: divergent reactivity by catalyst control." Chem. Commun. 50, no. 97 (2014): 15309–12. http://dx.doi.org/10.1039/c4cc07788a.

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NHC-catalyzed divergent annulation of enals with heterocyclic enones was developed to produce benzofuran/indole-containing ε-lactones or spiro-heterocycles in a highly diastereo- and enantioselective fashion.

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43

Su, Biyun, Yifan Hou, Li Wang, Xiaoteng Li, Dandan Pan, Tingyu Yan, Ao Zhang, Faida Paison, and Liqing Ding. "The Syntheses, Characterization and Crystal Structures of a Series of Heterocyclic β-Diketones and Their Isoxazole Compounds." Current Organic Synthesis 16, no. 8 (January 20, 2020): 1174–84. http://dx.doi.org/10.2174/1570179416666191022113022.

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Background: In the field of coordination chemistry, the introduction of heterocyclic substituents into the structure of β-diketone enables ligand to produce multiple coordination sites. The adoption of small steric oxime group into the structure of heterocyclic β-diketone by Schiff-base condensation will further increase coordination sites and facilitate the generation of polynuclear structures. Objective: A series of β-diketones (2a-2c) containing different heterocycles such as pyridine, thiophene and furan and their corresponding isoxazole compounds (3a-3c) were synthesized. Materials and Methods: The Claisen condensations were investigated in a solvent-free rheological phase system at room temperature to obtain heterocyclic β-diketones 2a-2c, which further reacted with hydroxylamine hydrochloride to obtain heterocyclic isoxazoles 3a-3c. All these compounds were well characterized by EA, IR, 1H NMR and X-ray crystal diffraction to confirm the structures. Synthetic mechanisms of compounds and the effects of different heterocycles on reactivity were discussed deeply. Result: 1H NMR indicated that these β-diketones do not exist as a total diketonic form but an equilibration between diketone and enol forms in CDCl3 solvent, in which the enol form accounts for 98.0% in 2a, 94.3% in 2b, 95.5% in 2c. While the crystal structures of 2a-2c showed that the reaction allows to isolate diketones in solid state. Crystal structures of 3a-3c showed that the neutral β-ketone oximes resonate and cyclize to form the target heterocyclic isoxazoles. Conclusion: SN1 nucleophilic substitution mechanism of Claisen ketoester condensation was proposed for the syntheses of 2a-2c, and SN1 single molecule nucleophilic substitution reaction mechanism was put forward for 3a-3c.

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Wu, Wenchao, Shuangli Xu, Yan Zhang, Xiu Wang, Ruotong Li, Fang Sun, Chenxia Yu, Tuanjie Li, Donghui Wei, and Changsheng Yao. "NHC-catalyzed β-specific addition of N-based nucleophiles to allenoates." Organic Chemistry Frontiers 7, no. 13 (2020): 1593–99. http://dx.doi.org/10.1039/d0qo00189a.

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N-heterocyclic carbene (NHC) catalyzed reactions of nitrogenous heterocycles or trifluoromethylated acylhydrazone with allenoates gave regiospecific β-adducts. DFT calculations rationalized the origination of regio- and E/Z selectivities.

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Abdel Hafez, Ali A. "Synthesis of Some Heterocyclic Sulfones Related to Quinolinol." Collection of Czechoslovak Chemical Communications 58, no. 9 (1993): 2222–26. http://dx.doi.org/10.1135/cccc19932222.

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It is well known that pyrazolone derivatives possess antifungal and antibacterial activities. Pyrazole and isoxazole derivatives are widely used in medicinal chemistry. In continuation of our work on the synthesis of heterocycles containing the quinoline moiety we synthesized different heterocyclic sulfones related to quinolinol.

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46

Gandhi, Shikha. "Catalytic enantioselective cross dehydrogenative coupling of sp3 C–H of heterocycles." Organic & Biomolecular Chemistry 17, no. 45 (2019): 9683–92. http://dx.doi.org/10.1039/c9ob02113b.

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The recent developments in the asymmetric functionalization of heterocycles via the catalytic enantioselective cross dehydrogenative coupling reactions of heterocyclic sp³ C–H bonds are highlighted in this review.

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Kumar, Suresh, Bhavna Saroha, Gourav Kumar, Ekta Lathwal, Sanjeev Kumar, Badri Parshad, Meena Kumari, Naveen Kumar, Mabel M. Mphahlele-Makgwane, and Peter R. Makgwane. "Recent Developments in Nanocatalyzed Green Synthetic Protocols of Biologically Potent Diverse O-Heterocycles—A Review." Catalysts 12, no. 6 (June 15, 2022): 657. http://dx.doi.org/10.3390/catal12060657.

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The dynamic growth in green organic synthetic methodologies for diverse heterocyclic scaffolds has substantially contributed to the field of medicinal chemistry over the last few decades. The use of hybrid metal nanocatalysts (NCs) is one such benign strategy for ensuring the advancement of modern synthetic chemistry by adhering to the principles of green chemistry, which call for a sustainable catalytic system that converts reacting species into profitable chemicals at a faster rate and tends to reduce waste generation. The metal nanoparticles (NPs) enhance the exposed surface area of the catalytic active sites, thereby making it easier for reactants and metal NCs to have an effective interaction. Several review articles have been published on the preparation of metal NCs and their uses for various catalytic heterocyclic transformations. This review will summarize different metal NCs for the efficient green synthesis of various O-heterocycles. Furthermore, the review will provide a concise overview of the role of metal NCs in the synthesis of O-heterocycles and will be extremely useful to researchers working on developing novel green and simple synthetic pathways to various O-heterocyclic-derived molecules.

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Stepanenko, Sergey A., Danil M. Shivtsov, Anton P. Koskin, Igor P. Koskin, Roman G. Kukushkin, Petr M. Yeletsky, and Vadim A. Yakovlev. "N-Heterocyclic Molecules as Potential Liquid Organic Hydrogen Carriers: Reaction Routes and Dehydrogenation Efficacy." Catalysts 12, no. 10 (October 17, 2022): 1260. http://dx.doi.org/10.3390/catal12101260.

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This study is focused on the development of liquid organic hydrogen carriers (LOHC) based on N-heterocyclic compounds. These LOHC-substrates are attractive for their lower hydrogen extraction temperature compared to cycloalkanes, which is caused by the low enthalpy of the dehydrogenation reaction of the N-heterocyclic compounds. The low hydrogen extraction temperature, as well as the low volatility of the heterocycles, provide high purity hydrogen from the reaction. Under similar reaction conditions, the comparison of the efficacy of three promising heterocycles (1-methyl-octahydroindole (8HMI), tetradecahydrophenazine and decahydroquinoline) was carried out in the presence of palladium-containing catalysts. As a result, the advantages of using catalysts supported by alumina, and the high perspectivity of the 8MHI application as a LOHC-substrate, were shown. The dehydrogenation of 8HMI in the presence of 1 wt.% Pd/Al2O3 allowed for reaching a 100% yield in hydrogen under the conditions of the standard catalytic test (1 h, 240 °C). In order to study the high reactivity of 8HMI, thermodynamic dehydrogenation reaction profiles were computationally evaluated, which showed that 8HMI was the most energetically preferred in the field of hydrogen storage from the studied heterocyclic compounds.

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Das, Tamal Kanti, and Akkattu T. Biju. "Imines as acceptors and donors in N-heterocyclic carbene (NHC) organocatalysis." Chemical Communications 56, no. 61 (2020): 8537–52. http://dx.doi.org/10.1039/d0cc03290e.

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The application of imines as electrophiles (acceptors) or as a source of nucleophiles (donors) in N-heterocyclic carbene (NHC) catalysis for the synthesis of various nitrogen heterocycles and functionalized amines is presented.

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Nehra, Bhupender, Bijo Mathew, and Pooja A. Chawla. "A Medicinal Chemist’s Perspective Towards Structure Activity Relationship of Heterocycle Based Anticancer Agents." Current Topics in Medicinal Chemistry 22, no. 6 (March 2022): 493–528. http://dx.doi.org/10.2174/1568026622666220111142617.

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Aim: This paper aims to describe the structure activity relationship of heterocyclic deriva-tives with multi-targeted anticancer activity. Objectives: With the following goals in mind, this review tries to describe significant recent advances in the medicinal chemistry of heterocycle-based compounds: (1) To shed light on recent literature focused on heterocyclic derivatives' anticancer potential; (2) To discuss recent advances in the medic-inal chemistry of heterocyclic derivatives, as well as their biological implications for cancer eradica-tion; (3) To summarise the comprehensive correlation of structure activity relationship (SAR) with pharmacological outcomes in cancer therapy. Background: Cancer remains one of the major serious health issues in the world today. Cancer is a complex disease in which improperly altered cells proliferate at an uncontrolled, rapid, and severe rate. Variables such as poor dietary habits, high stress, age, and smoking, can all contribute to the development of cancer. Cancer can affect almost any organ or tissue, although the brain, breast, liver, and colon are the most frequently affected organs. For several years, surgical operations and irradia-tion have been in use along with chemotherapy as a primary treatment of cancer, but still, effective treatment of cancer remains a huge challenge. Chemotherapy is now considered one of the most ef-fective strategies to eradicate cancer, although it has been shown to have a number of cytotoxic and unfavourable effects on normal cells. Despite all of these cancer treatments, there are several other targets for anticancer drugs. Cancer can be effectively eradicated by focusing on these targets, includ-ing cell-specific and receptor-specific targets such as tyrosine kinase receptors (TKIs). Heterocyclic scaffolds also have a variety of applications in drug development and are a common moiety in the pharmaceutical, agrochemical, and textile industries. Methods: The association between structural activity relationship data of many powerful compounds and their anticancer potential in vitro and in vivo has been studied. SAR of powerful heterocyclic compounds can also be generated using molecular docking simulations, as reported in literature. Conclusions: Heterocycles have a wide range of applications, from natural compounds to synthesised derivatives with powerful anticancer properties. To avoid cytotoxicity or unfavourable effects on normal mammalian cells due to a lack of selectivity towards the target site, as well as to reduce the occurrence of drug resistance, safer anticancer lead compounds with higher potency and lower cyto-toxicity are needed. This review emphasizes on design and development of heterocyclic lead com-pounds with promising anticancer potential.

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Journal articles on the topic 'Heterocyclic'

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