A highly enantioselective N‐heterocyclic carbene (NHC) catalyzed formal 3+2 annulation of α,β‐unsaturated aldehydes with azaaurones or aurone generating spiro‐heterocycles has been developed. The ...protocol represents a unique NHC‐activation‐based approach to access spiro‐heterocyclic derivatives bearing a quaternary stereogenic center with high optical purity (up to 95 % ee).
Ring, ring: A highly enantioselective formal 3+2 annulation of α,β‐unsaturated aldehydes with azaaurones or aurone is catalyzed by an N‐heterocyclic carbene (NHC) and generates spiro‐heterocycles. The protocol represents a unique NHC activation‐based approach to access spiro‐heterocyclic derivatives bearing a quaternary stereogenic center with high optical purity.
The present review article offers a detailed account of the design strategies employed for the synthesis of nitrogen-containing anticancer agents. The results of different studies describe the ...N-heterocyclic ring system is a core structure in many synthetic compounds exhibiting a broad range of biological activities. Benzimidazole, benzothiazole, indole, acridine, oxadiazole, imidazole, isoxazole, pyrazole, triazoles, quinolines and quinazolines including others drugs containing pyridazine, pyridine and pyrimidines are covered. The following studies of these compounds suggested that these compounds showed their antitumor activities through multiple mechanisms including inhibiting protein kinase (CDK, MK-2, PLK1, kinesin-like protein Eg5 and IKK), topoisomerase I and II, microtubule inhibition, and many others. Our concise representation exploits the design and anticancer potency of these compounds. The direct comparison of anticancer activities with the standard enables a systematic analysis of the structure-activity relationship among the series.
Display omitted
•The roles of various new N-heterocyclic moieties against different human cancer cell lines are discussed.•The SAR of the newly synthesized derivative are illustrated in figures.•Novel fused heterocyclic moieties and new complexes showing significant anticancer properties are also presented.•Interactions of some newly synthesized compounds with the receptors is confirmed by docking studies.
C3‐Functionalization of Imidazo[1,2‐a]pyridines Tashrifi, Zahra; Mohammadi‐Khanaposhtani, Mohammad; Larijani, Bagher ...
European journal of organic chemistry,
January 23, 2020, Letnik:
2020, Številka:
3
Journal Article
Recenzirano
Among nitrogen‐containing organic compounds, imidazo1,2‐apyridines, and especially C3‐functionalized imidazo1,2‐apyridines, have a wide range of industrial applications in the fields of optics, ...material science, and organometallics. This scaffolds also have various medicinal uses due to their antiviral, cytotoxic, antibacterial, fungicidal, and antiinflammatory activities as they are found in many commercially available drugs such as Alpidem, Miroprofen, and Zolimidine. In this review, we summarized and classified the latest synthetic methods for the preparation of C3‐functionalized imidazo1,2‐apyridines based on the type of the substituents on the 3‐position of imidazo1,2‐apyridine including C3‐alkylation, C3‐arylation, C3‐carbonylation, C3‐sulfenylation, C3‐selenation, C3‐N‐Substitution, C3‐phosphonation, and C3‐halogenation.
In this review, the synthetic methods of C3‐functionalized imidazo1,2‐apyridines were described based on the type of substituents on the 3‐position of imidazo1,2‐apyridine moiety were categorized as follows: C3‐alkylation, C3‐arylation, C3‐carbonylation, C3‐sulfenylation, C3‐selenation, C3‐N‐Substitution, C3‐phosphonation, and C3‐halogenation.
Heterocycles constitute a very important class of compounds in organic chemistry. The heterocyclic frameworks represent the main structural subunits of various natural products and biologically ...active compounds. The formation of higher-membered heterocyclic compounds has been a center of focus for a very long time and has attracted great attention for the development of improved synthetic approaches toward milder, clean, and high yielding strategies. Several classical approaches involve carbon-heteroatom bond-forming reactions like dipolar cycloaddition for ring closure, reductive amination, or nucleophilic substitution in the synthesis of these compounds. This review article is focused on the synthesis of several higher-membered heterocyclic compounds.
Display omitted
•The first oxo- and carboindirubin-N-glycosides were prepared.•The oxo-compounds were formed as separable mixtures of E/Z-isomers.•The carbo-compounds were formed as single ...geometrical isomers.
A series of hitherto unknown oxo- and carboindirubin-N-glycosides were prepared by reaction of isatin-N-glycosides with coumaran-3-one and indan-1-one, respectively. 2009 Elsevier Ltd. All rights reserved.
The visible‐light‐promoted decarboxylation of α‐imino‐oxy propionic acids for the generation of iminyl radicals has been accomplished through the use of Ir(dFCF3ppy)2(dtbbpy)PF6 as a photoredox ...catalyst. Different from visible‐light‐promoted homolysis and single‐electron reduction of oxime derivatives, this strategy provides a novel catalytic cycle for alkene carboimination through a sequence comprising N‐radical generation, iminyl radical cyclization, intermolecular conjugate addition to a Michael acceptor, and single‐electron reduction to afford various pyrroline derivatives in an overall redox‐neutral process. The indolizidine alkaloid skeleton could be easily constructed from a pyrroline derivative prepared by this synthetic method.
Radical closure: A redox‐neutral radical reaction cascade of α‐imino‐oxy propionic acids with various Michael acceptors, using iridium‐photoredox catalysis, delivers valuable pyrrolines. These reaction cascades comprise oxidative iminyl radical generation, carboimination cyclization, and subsequent intermolecular radical conjugate addition.
Heterocyclic chemistry constitutes an essential branch of organic chemistry and heterocycles are widely known to display an array of biological properties. Pyrazoles represent key structural motifs ...in heterocyclic chemistry and are present in a large number of biologically active molecules relevant to the pharmaceutical and agrochemical industries. Compounds incorporating the pyrazolyl structural unit are being developed in a wide variety of therapeutic areas including CNS, metabolic diseases, and oncology. The current review summarizes recent advances in the synthesis of tetrasubstituted pyrazoles. The contents are discussed in five sections: (a) 1,3-dipolar cycloadditions, (b) related 1,3-dipolar cycloadditions, (c) condensations, (d) allenylphosphonates, and (e) synthesis of fused pyrazole containing heterocycles.
Display omitted
▸ Heterocycles display an array of biological properties. ▸ Pyrazole structural motif is present in a wide variety of bioactive compounds. ▸ Several FDA approved drugs incorporate pyrazole unit in their core structure. ▸ The current review highlights on synthesis of the tetrasubstituted pyrazoles.
Since a variety of benzo-fused nitrogen- and oxygen-based bioactive heterocyclic moieties are present in the form of benzoxazinones, spirooxindole-based heterocyclic compounds, coumarinfused ...heterocyclic compounds, and 2H-indazoles, this review article briefly describes some of the major advancements and developments in the area of 1,4-benzoxazine-3-ones, 1,4-benzoxazin-2- ones, spiropyrrolidine and spiropyrrolizine-based ring compounds, coumarin-fused compounds, benzopyran- fused coumarins and a 2H-indazoles class of bioheterocycles. Thus, keeping in view the medicinal importance of these bioactive benzo-fused heterocycles, special attention has been given to their synthesis as well as medicinal/pharmaceutical properties in detail.
Herein, we develop a new approach to directly access architecturally complex polycyclic indolines from readily available indoles and bicyclo1.1.0butanes (BCBs) through formal cycloaddition promoted ...by commercially available Lewis acids. The reaction proceeded through a stepwise pathway involving a nucleophilic addition of indoles to BCBs followed by an intramolecular Mannich reaction to form rigid indoline‐fused polycyclic structures, which resemble polycyclic indole alkaloids. This new reaction tolerated a wide range of indoles and BCBs, thereby allowing the one‐step construction of various rigid indoline polycycles containing up to four contiguous quaternary carbon centers.
An intermolecular formal cycloaddition of indoles with bicyclo1.1.0butanes promoted by commercially available Lewis acids has been disclosed, allowing one‐step rapid construction of rigid indoline polycyclic structures via a cascade nucleophilic addition and Mannich reaction process.
