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Heterocyclic chemistry

M A Rajora, J W H Lou, G Zheng
Porphyrins are organic heterocyclic macrocycles with photophysical properties well-suited for clinical phototherapy and cancer imaging. However, their wider application in the clinical management of disease is barred by poor aqueous solubility, bioavailability, tumour accumulation and skin phototoxicity. These limitations instigated the development of supramolecular platforms that improved porphyrin pharmacokinetics and tumour-homing. The supramolecular formulation of porphyrins also facilitates single agent-mediated deeper tissue photoactivation, extended imaging and theranostic multimodality, and synergistic application of multiple therapies...
October 19, 2017: Chemical Society Reviews
Zhijun Li, Kim A Munro, Mina Narouz, Bin Hao, Cathleen M Crudden, J Hugh Horton, Hongxia Hao
Surface chemistry is a key enabler for various biosensing applications. Surface plasmon resonance (SPR)-based biosensors routinely employ thiol-based chemistry for the linker layer between gold-coated support surfaces and functional biosensor surfaces. However, there is a growing awareness that such sensor surfaces are prone to oxidation/degradation problems in the presence of oxygen, and previous efforts to improve the stability have shown limited advancements. As an alternative, recent studies employing N-heterocyclic carbene (NHC) self assembled monolayers (SAMs) deposited on gold have shown significant promise in this area...
October 19, 2017: ACS Applied Materials & Interfaces
Linda Ă…kerbladh, Shiao Y Chow, Luke R Odell, Mats Larhed
Invited for this month's cover are researchers from the Division of Organic Pharmaceutical Chemistry, Department of Medicinal Chemistry, Uppsala University (Sweden). The research interests in the group span areas such as enzyme inhibitors, new antibiotics, angiotensin II AT2R ligands, PET tracers, palladium catalysis, heterocycle synthesis, and the development of novel multicomponent reactions. In particular, sequential carbonylation and cyclization appeal to us as a convenient and straightforward synthetic route for the synthesis of heterocycles...
October 2017: ChemistryOpen
Yangye Jiang, Kun Xu, Chengchu Zeng
The preparation and transformation of heterocyclic structures have always been of great interest in organic chemistry. Electrochemical technique provides a versatile and powerful approach to the assembly of various heterocyclic structures. In this review, we examine the advance in relation to the electrochemical construction of heterocyclic compounds published since 2000 via intra- and intermolecular cyclization reactions.
October 17, 2017: Chemical Reviews
Rita Morigi, Beatrice Vitali, Cecilia Prata, Rogers A A Palomino, Alessandra Graziadio, Alessandra Locatelli, Mirella Rambaldi, Alberto Leoni
BACKGROUND: Fused five-membered heterocyclic rings containing bridgehead nitrogen atom are particularly versatile in the field of medicinal chemistry because of their different biological activities. Among them, the imidazo[2,1-b]thiazole is an attractive fused heterocyclic core that has been extensively studied. OBJECTIVE: The aim of the current study was to study the therapeutic applications of imidazo[2,1-b]thiazole derivatives as antimicrobial agents for the treatment of genitourinary infections...
October 10, 2017: Medicinal Chemistry
Vijayendar Venepally, Ram Chandra Reddy Jala
Heterocyclic compounds are the interesting core structures for the development of new bioactive compounds. Fatty acids are derived from renewable raw materials and exhibit various biological activities. Several researchers are amalgamating these two bioactive components to yield bioactive hybrid molecules with some desirable features. Heterocyclic-fatty acid hybrid derivatives are a new class of heterocyclic compounds with a broad range of biological activities and significance in the field of medicinal chemistry...
October 3, 2017: European Journal of Medicinal Chemistry
Danylo Kaminskyy, Anna Kryshchyshyn, Roman Lesyk
Rhodanines, as one of the 4-thiazolidinones subtypes, are recognized as privileged heterocycles in medicinal chemistry. The main achievements include the development of drug-like molecules with numerous biological activities as well as approved drugs. Among rhodanines, 5-ene-rhodanines are of special interest, and are often claimed as pan assay interference compounds due to Michael acceptor functionality. Areas covered: Herein, the synthetic protocols for rhodanines and their transformation are reviewed. Biological activity is briefly discussed as well as biotargets, mode of actions and optimization directions...
October 11, 2017: Expert Opinion on Drug Discovery
Ponnam Devendar, Guang-Fu Yang
Modern agricultural chemistry has to support farmers by providing innovative agrochemicals. In this context, the introduction of sulfur atoms into an active ingredient is still an important tool in modulating the properties of new crop-protection compounds. More than 30% of today's agrochemicals contain at least one sulfur atom, mainly in fungicides, herbicides and insecticides. A number of recently developed sulfur-containing agrochemical candidates represent a novel class of chemical compounds with new modes of action, so we intend to highlight the emerging interest in commercially active sulfur-containing compounds...
October 9, 2017: Topics in Current Chemistry (Journal)
Dmitrii S Bolotin, Nadezhda A Bokach, Marina Ya Demakova, Vadim Yu Kukushkin
This review classifies and summarizes the past 10-15 years of advancements in the field of metal-involving (i.e., metal-mediated and metal-catalyzed) reactions of oximes. These reactions are diverse in nature and have been employed for syntheses of oxime-based metal complexes and cage-compounds, oxime functionalizations, and the preparation of new classes of organic species, in particular, a wide variety of heterocyclic systems spanning small 3-membered ring systems to macroheterocycles. This consideration gives a general outlook of reaction routes, mechanisms, and driving forces and underlines the potential of metal-involving conversions of oxime species for application in various fields of chemistry and draws attention to the emerging putative targets...
October 9, 2017: Chemical Reviews
A Matsumoto, A J Stephenson-Brown, T Khan, T Miyazawa, H Cabral, K Kataoka, Y Miyahara
Boronic acids are well known for their ability to reversibly interact with the diol groups found in sugars and glycoproteins. However, they are generally indiscriminate in their binding. Herein we describe the discovery of a group of heterocyclic boronic acids demonstrating unusually high affinity and selectivity for sialic acids (SAs or N-acetylneuraminic acid), which are sugar residues that are intimately linked with tumor growth and cancer progression. Remarkably, these interactions strengthen under the weakly acidic pH conditions associated with a hypoxic tumoral microenvironment...
September 1, 2017: Chemical Science
Danylo Kaminskyy, Anna Kryshchyshyn, Roman Lesyk
The presented review is an attempt to summarize a huge volume of data on 5-ene-4-thiazolidinones being a widely studied class of small molecules used in modern organic and medicinal chemistry. The manuscript covers approaches to the synthesis of 5-ene-4-thiazolidinone derivatives: modification of the C5 position of the basic core; synthesis of the target compounds in the one-pot or multistage reactions or transformation of other related heterocycles. The most prominent pharmacological profiles of 5-ene derivatives of different 4-thiazolidinone subtypes belonging to hit-, lead-compounds, drug-candidates and drugs as well as the most studied targets have been discussed...
September 20, 2017: European Journal of Medicinal Chemistry
Khurshed Bozorov, Li Fei Nie, Jiangyu Zhao, Haji A Aisa
2-Aminothiophenes are important five-membered heterocyclic building blocks in organic synthesis, and the chemistry of these small molecules is still developing based on the discovery of cyclization by Gewald. Another attractive feature of 2-aminothiophene scaffolds is their ability to act as synthons for the synthesis of biological active thiophene-containing heterocycles, conjugates and hybrids. Currently, the biological actions of 2-aminothiophenes or their 2-N-substituted analogues are still being investigated because of their various mechanisms of action (e...
September 21, 2017: European Journal of Medicinal Chemistry
Clementina M M Santos, Vera L M Silva, Artur M S Silva
Chromones, six-membered oxygen heterocycles, and pyrazoles, five-membered two-adjacent-nitrogen-containing heterocycles, represent two important classes of biologically active compounds. Certain derivatives of these scaffolds play an important role in medicinal chemistry and have been extensively used as versatile building blocks in organic synthesis. In this context, we will discuss the most relevant advances on the chemistry that involves both chromone and pyrazole rings. The methods reviewed include the synthesis of chromone-pyrazole dyads, synthesis of chromone-pyrazole-fused compounds, and chromones as starting materials in the synthesis of 3(5)-(2-hydroxyaryl)pyrazoles, among others...
October 5, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Naser Foroughifar, Somayeh Karimi Beromi, Hoda Pasdar, Masoumeh Shahi
Heterocyclic compounds containing a pyrimidine nucleus are of special interests thanks to their applications in medicinal chemistry as they are the basic skeleton of several bioactive compounds such as antifungal, antibacterial, antitumor and antitubercular. As a part of our research in the synthesis of pyrimidine derivatives containing biological activities, some new tetrahydropyrimidine derivatives (1-10) were synthesized via Biginelli reaction using HCl or DABCO as a catalyst with good yields. All structures of products were confirmed by IR, (1)H NMR and (13)C NMR spectroscopy...
2017: Iranian Journal of Pharmaceutical Research: IJPR
Shasha Zhang, Dangdang Li, Zehua Song, Chuanli Zang, Lu Zhang, Xiushi Song, Shengkun Li
With structural diversity and versatile biological properties, drimane meroterpenoids have drawn remarkable attention in drug development. The stagnant progress made in the structure optimization and SAR study of this kind of natural product for agrochemicals was mainly a result of inefficient construction. Compared with the reported challenging coupling reaction ("1 + 1" tactic), "carbon assimilation" was conceived and used for the rapid construction of drimanyl meroterpenoid mimics, in which the newly formed covalent bond was directly from the old one of the drimanyl subunit ("2 + 0" tactic), which features atom economy, step economy, and facile preparation...
October 5, 2017: Journal of Agricultural and Food Chemistry
Marco T Sabatini, Lee T Boulton, Tom D Sheppard
Chemical reactions for the formation of amide bonds are among the most commonly used transformations in organic chemistry, yet they are often highly inefficient. A novel protocol for amidation using a simple borate ester catalyst is reported. The process presents significant improvements over other catalytic amidation methods in terms of efficiency and safety, with an unprecedented substrate scope including functionalized heterocycles and even unprotected amino acids. The method was used to access a wide range of functionalized amide derivatives, including pharmaceutically relevant targets, important synthetic intermediates, a catalyst, and a natural product...
September 2017: Science Advances
Hujun Xie, Yang Li, Lihong Wang, Jian Kuang, Qunfang Lei, Wenjun Fang
Quantum chemistry calculations have been employed to study the mechanisms of nickel-catalyzed Suzuki-Miyaura cross-coupling reactions of benzylic carbamates with arylboronic esters, and the energy profiles have been computed to evaluate possible origins for the generation of different stereochemistry products. It has been demonstrated that the mechanism can be divided into three steps: oxidative addition, transmetallation and reduction elimination. Transmetallation is the rate-limiting step for the whole reaction cycle, and oxidative addition controls the stereoselectivity of the resulting products...
September 22, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Taotao Lu, Chu-Fan Yang, Li-Yi Zhang, Fan Fei, Xue-Tai Chen, Zi-Ling Xue
A hexadentate macrocyclic N-heterocyclic carbene (NHC) ligand precursor (H4L)(PF6)4 containing four benzimidazolium and two secondary amine groups, has been synthesized and characterized. Coordination chemistry of this new macrocyclic diamine-tetracarbene ligand has been studied by the synthesis of its Ag(I), Au(I), Ni(II), and Pd(II) complexes. Reactions of (H4L)(PF6)4 with different equiv of Ag2O result in Ag(I) complexes [Ag(H2L)](PF6)3 (1) and [Ag2(H2L)](PF6)4 (2). A mononuclear Au(I) complex [Au(H2L)](PF6)3 (3) and a trinuclear Au(I) complex [Au3(H2L)(Cl)2](PF6) (4) are obtained by transmetalation of 1 and 2 with AuCl(SMe2), respectively...
October 2, 2017: Inorganic Chemistry
Xiaolong Yu, Kehao Chen, Shan Guo, Pengfei Shi, Chao Song, Jin Zhu
Cobaltacycle synthesis via C-H activation has been achieved for the first time, providing key mechanistic insight into cobalt catalytic chemistry. N-Chloroamides are used as a directing synthon for cobalt-catalyzed room-temperature C-H activation and construction of heterocycles. Alkynes as coupling partners allow convenient access to isoquinolones, a class of synthetically and pharmaceutically important compounds. The broad substrate scope enables a diverse range of substitution patterns to be incorporated into the heterocyclic scaffold...
October 6, 2017: Organic Letters
Hiroaki Iwamoto, Yu Ozawa, Koji Kubota, Hajime Ito
The copper(I)-catalyzed regio- and stereoselective intramolecular alkylation of propargyl ethers and amines bearing an alkyl electrophilic moiety has been developed. The reaction showed high functional group tolerance and gave highly functionalized alkenylboronates bearing heterocyclic rings, which are versatile synthetic intermediates in organic chemistry. The borylation products can be transformed into multisubstituted alkenes through stereospecific transformations. Mechanistic studies showed that the chemo- and stereoselectivity of copper(I)-catalyzed borylation depends on the type of leaving group...
September 26, 2017: Journal of Organic Chemistry
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