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Journal articles on the topic 'Oxa-heterocycles'

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Published: 4 June 2025

Last updated: 1 August 2025

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1

Zhang, Liang, Neng-Jie Mou, Dong-Rong Xiao, et al. "Regioselective synthesis of fused oxa-heterocycles via iodine-mediated annulation of cyclic 1,3-dicarbonyl compounds with propargylic alcohols." Organic Chemistry Frontiers 8, no. 6 (2021): 1155–62. http://dx.doi.org/10.1039/d0qo01496f.

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2

M., M. DUTTA, and C. S. KATAKY J. "Studies on Biologically Active Heterocycles. Part-V1. Synthesis and Biological Activity of Heterocyclic Azadienes and Phosphate/Thiophosphate Derivatives of 1,3,4-Oxa- and Thiadiazoles." Journal of Indian Chemical Society Vol. 69, Sep 1992 (1992): 599–601. https://doi.org/10.5281/zenodo.6032446.

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Regional Research Laboratory. Jorhat-785 006 <em>Manuscript received 28 January 1991, revised 30 October 1991, accepted 3 July 1992</em> Studies on Biologically Active Heterocycles. Part-V<sup>1</sup>. Synthesis and Biological Activity of Heterocyclic Azadienes and Phosphate/Thiophosphate Derivatives of 1,3,4-Oxa- and Thiadiazoles.

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3

Khramtsova, Ekaterina E., Aleksandr D. Krainov, Maksim V. Dmitriev, and Andrey N. Maslivets. "Cycloaddition of 4-Acyl-1H-pyrrole-2,3-diones Fused at [e]-Side and Cyanamides: Divergent Approach to 4H-1,3-Oxazines." Molecules 27, no. 16 (2022): 5257. http://dx.doi.org/10.3390/molecules27165257.

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4-Acyl-1H-pyrrole-2,3-diones fused at [e]-side with a heterocyclic moiety are suitable platforms for the development of a hetero-Diels–Alder-reaction-based, diversity-oriented approaches to series of skeletally diverse heterocycles. These platforms are known to react as oxa-dienes with dienophiles to form angular 6/6/5/6-tetracyclic alkaloid-like heterocycles and are also prone to decarbonylation at high temperatures resulting in generation of acyl(imidoyl)ketenes, bidentate aza- and oxa-dienes, which can react with dienophiles to form skeletally diverse products (angular tricyclic products or

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4

Lystsova, Ekaterina A., Ekaterina E. Khramtsova, and Andrey N. Maslivets. "Acyl(imidoyl)ketenes: Reactive Bidentate Oxa/Aza-Dienes for Organic Synthesis." Symmetry 13, no. 8 (2021): 1509. http://dx.doi.org/10.3390/sym13081509.

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Polyfunctional building blocks are essential for the implementation of diversity-oriented synthetic strategies, highly demanded in small molecule libraries’ design for modern drug discovery. Acyl(imidoyl)ketenes are highly reactive organic compounds, bearing both oxa- and aza-diene moieties, conjugated symmetrically to the ketene fragment, enabling synthesis of various skeletally diverse heterocycles on their basis. The highlights of reactions utilizing acyl(imidoyl)ketenes are high yields, short reaction time (about several minutes), high selectivity, atom economy, and simple purification pro

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5

Aronica, Laura, and Gianluigi Albano. "Cyclization Reactions for the Synthesis of Phthalans and Isoindolines." Synthesis 50, no. 06 (2018): 1209–27. http://dx.doi.org/10.1055/s-0037-1609175.

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Oxygen and nitrogen heterocycles are present in a vast number of natural substrates and biologically active molecules. In particular, phthalan and isoindoline subunits are found in many classes of products such as antibiotics, antioxidants, antimycotics, pigments, and fluorophores. Therefore several procedures dedicated to the construction of these heterocycles have been developed. In this review, a detailed analysis of the literature data regarding the synthesis of these nuclei via cyclization reactions is reported.1 Introduction2 Phthalans2.1 Oxa-Pictet–Spengler Reaction2.2 Garratt–Braverman

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6

Fernández-Pérez, Héctor, Pablo Etayo, José Luis Núñez-Rico, Bugga Balakrishna, and Anton Vidal-Ferran. "Ring-opening of enantiomerically pure oxa-containing heterocycles with phosphorus nucleophiles." RSC Adv. 4, no. 102 (2014): 58440–47. http://dx.doi.org/10.1039/c4ra10432c.

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7

Manna, Sibasish, Koushik Das, Sougata Santra, Emily V. Nosova, Grigory V. Zyryanov, and Sandipan Halder. "Structural and Synthetic Aspects of Small Ring Oxa- and Aza-Heterocyclic Ring Systems as Antiviral Activities." Viruses 15, no. 9 (2023): 1826. http://dx.doi.org/10.3390/v15091826.

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Antiviral properties of different oxa- and aza-heterocycles are identified and properly correlated with their structural features and discussed in this review article. The primary objective is to explore the activity of such ring systems as antiviral agents, as well as their synthetic routes and biological significance. Eventually, the structure–activity relationship (SAR) of the heterocyclic compounds, along with their salient characteristics are exhibited to build a suitable platform for medicinal chemists and biotechnologists. The synergistic conclusions are extremely important for the intr

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8

Lelyukh, M. I. "Biological activity of heterocyclic systems based on functionally substituted 1,3,4-thia(oxa)diazoles (a review)." Farmatsevtychnyi zhurnal, no. 6 (December 21, 2019): 43–53. http://dx.doi.org/10.32352/10.32352/0367-3057.6.19.05.

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1,3,4-Thiadiazole and oxadiazole hetetocycles are well-known pharmacophore scaffolds, which possess wide possibility for chemical modification and identified diverse pharmacological potential. Such essential and many-sided activities let to consider the mentioned heterocycles as ones of the crucial for expression of pharmacological activity, which confirm their importance for medicinal chemistry. Moreover, 1,3,4-oxadiazole cycle is a bioisostere for carboxylic, amide and ester groups, which mostly contribute to enhancement the pharmacological activity by participating in hydrogen bonding inter

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9

Kaufman, Teodoro S., and Enrique L. Larghi. "The Oxa-Pictet-Spengler Cyclization: Synthesis of Isochromans and Related Pyran-Type Heterocycles." Synthesis, no. 2 (2006): 187–220. http://dx.doi.org/10.1055/s-2005-918502.

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10

Majumdar, K. C., B. Chattopadhyay, and K. Ray. "Novel synthesis of medium-sized oxa-heterocycles by palladium-catalyzed intramolecular Heck reaction." Tetrahedron Letters 48, no. 43 (2007): 7633–36. http://dx.doi.org/10.1016/j.tetlet.2007.08.121.

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11

Gurubrahamam, Ramani, Koppanathi Nagaraju, and Kwunmin Chen. "Organocatalytic synthesis of densely functionalized oxa-bridged 2,6-epoxybenzo[b][1,5]oxazocine heterocycles." Chemical Communications 54, no. 47 (2018): 6048–51. http://dx.doi.org/10.1039/c8cc02565g.

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12

Yang, Wen, and Jianwei Sun. "Organocatalytic Enantioselective Synthesis of 1,4-Dioxanes and Other Oxa-Heterocycles by Oxetane Desymmetrization." Angewandte Chemie International Edition 55, no. 5 (2015): 1868–71. http://dx.doi.org/10.1002/anie.201509888.

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13

Fernandez-Perez, Hector, Pablo Etayo, Jose Luis Nunez-Rico, Bugga Balakrishna, and Anton Vidal-Ferran. "ChemInform Abstract: Ring-Opening of Enantiomerically Pure Oxa-Containing Heterocycles with Phosphorus Nucleophiles." ChemInform 46, no. 18 (2015): no. http://dx.doi.org/10.1002/chin.201518242.

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14

Yang, Wen, and Jianwei Sun. "Organocatalytic Enantioselective Synthesis of 1,4-Dioxanes and Other Oxa-Heterocycles by Oxetane Desymmetrization." Angewandte Chemie 128, no. 5 (2015): 1900–1903. http://dx.doi.org/10.1002/ange.201509888.

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15

Ahmad, Tauqir, and Nisar Ullah. "The oxa-Michael reaction in the synthesis of 5- and 6-membered oxygen-containing heterocycles." Organic Chemistry Frontiers 8, no. 6 (2021): 1329–44. http://dx.doi.org/10.1039/d0qo01312a.

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In this review, we provide an updated account on the recent advances and applications of oxa-Michael reaction in the synthesis 5- and 6-membered monocyclic oxygen-containing heterocyclic compounds published in the literature since 2013 to date.

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16

Renslo, Adam R., Hongwu Gao, Priyadarshini Jaishankar, Revathy Venkatachalam, and Mikhail F. Gordeev. "Synthesis of Aza-, Oxa-, and Thiabicyclo[3.1.0]hexane Heterocycles from a Common Synthetic Intermediate." Organic Letters 7, no. 13 (2005): 2627–30. http://dx.doi.org/10.1021/ol050730h.

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17

Sánchez-Roselló, María, Carlos del Pozo, and Javier Miró. "Cross-Metathesis/Intramolecular (Hetero-)Michael Addition: A Convenient Sequence for the Generation of Carbo- and Heterocycles." Synthesis 49, no. 13 (2017): 2787–802. http://dx.doi.org/10.1055/s-0036-1589497.

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The high stability and functional group compatibility of ruthenium carbene complexes confer them a great ability to catalyze domino processes. For this reason, the combination of metathesis reactions with additional transformations in a domino fashion has been exploited extensively, with the result of expanding the utility of ruthenium carbene complexes beyond that of just olefin metathesis. Among those domino processes, it is worth mentioning the sequence of cross-metathesis/intramolecular Michael addition, which allows for the generation of a wide variety of carbo- and heterocycles in a very

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18

Joubert, Jacques, Natasha Strydom, Werner J. Geldenhuys, Yolande Greyling, Sandra V. Dyk, and Sarel F. Malan. "Hexacyclododecylamines with Sigma-1 Receptor Affinity and Calcium Channel Modulating Ability." Open Medicinal Chemistry Journal 13, no. 1 (2019): 29–39. http://dx.doi.org/10.2174/1874104501913010029.

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Introduction: Recent research points to the Sigma Receptor (σR) as a possible neuromodulatory system with multi-functional action and σ1Rs have been suggested as a drug target for a number of CNS conditions. Hexacyclododecylamines have shown σ1R activity and provide an advantageous scaffold for drug design that can improve the blood-brain barrier permeability of privileged structures. Methods and Materials: A series of oxa- and aza- hexaxcyclododecylamines were synthesised and evaluated for sigma-1 receptor activity and voltage-gated calcium channel blocking ability to determine the effect of

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19

Serbezeanu, Diana, Tachita Vlad-Bubulac, Elena Hamciuc, et al. "Study on Thermal and Flame Retardant Properties of Phosphorus-containing Polyimides." Revista de Chimie 72, no. 4 (2021): 13–21. http://dx.doi.org/10.37358/rc.21.4.8452.

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The present study aimed to design macromolecular architectures having imide core in the main chain and bearing two 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide heterocycles in the side chain of each structural units as a synergetic two components key factor to induce attractive flame retardant properties in the resulted materials. The synthesis pathway consisted in the classical polycondensation reaction strategy using a phosphorus-containing diamine synthesized in the laboratory and three commercial dianhydrides co-monomers. The chemical structure confirmation of the phosphorus-containing

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20

Riveira, Martín J., Agustina La-Venia, and Mirta P. Mischne. "Advances in bridged 1,2,4-trioxane-based chemistry. A divergent approach to oxa-heterocycles based on ambident reactivity." Tetrahedron Letters 51, no. 5 (2010): 804–7. http://dx.doi.org/10.1016/j.tetlet.2009.11.135.

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21

Zeng, Tianlong, Jingyang Kong, Hongkai Wang, Lingyan Liu, Weixing Chang, and Jing Li. "Substituent‐Controlled Divergent Cascade Cycloaddition Reactions of Chalcones and Arylalkynols: Access to Spiroketals and Oxa ‐Bridged Fused Heterocycles." Advanced Synthesis & Catalysis 363, no. 16 (2021): 4024–32. http://dx.doi.org/10.1002/adsc.202100523.

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22

Shinkevich, E. Yu, M. S. Novikov, A. F. Khlebnikov, R. R. Kostikov, J. Kopf, and J. Magull. "New type of transannular reactions in azirine-fused medium-size heterocycles: Selective transformations of azirino[2,1-e][1,6]benzoxazocines and -benzothiazocines into oxa(thia)zine and oxa(thia)zole derivatives." Russian Journal of Organic Chemistry 43, no. 7 (2007): 1065–79. http://dx.doi.org/10.1134/s1070428007070214.

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23

Praveen, Cherukupally, Javvaji Rama Rao, Padi Pratap Reddy, Kaga Mukkanti, and Gade Srinivas Reddy. "Facile synthesis of 6-aryl-5H-8-oxa-4b, 7-diaza-benzo[a]azulen-9-one derivatives, new tricyclic heterocycles." Journal of Heterocyclic Chemistry 45, no. 4 (2008): 1083–87. http://dx.doi.org/10.1002/jhet.5570450421.

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24

Quiroga, Diego, and Ericsson Coy-Barrera. "Synthesis of Antifungal Heterocycle-Containing Mannich Bases: A Comprehensive Review." Organics 4, no. 4 (2023): 503–23. http://dx.doi.org/10.3390/org4040035.

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Mannich bases are a class of organic compounds usually obtained by the condensation reaction between an amine, a compound with active hydrogens, and an aldehyde. They are versatile intermediates in organic synthesis, and those compounds containing this motif find applications in pharmaceutical, agrochemical, and even material fields since they are widely known for their wide range of biological activities, including antimicrobial properties. Thus, as part of our interest in antifungal agents, this narrative review aimed to gather information from the literature on the synthesis of various repr

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25

Majumdar, K., and B. Chattopadhyay. "Novel Synthesis of Nine-Membered Oxa-Heterocycles by Pd(0)-Catalyzed Intramolecular Heck Reaction via Unusual 9-endo-trig-Mode Cyclization." Synlett 2008, no. 07 (2008): 979–82. http://dx.doi.org/10.1055/s-2008-1072510.

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26

Das, Sajal Kumar, та Gautam Panda. "β-Hydroxy-α-tosyloxy esters as chiral building blocks for the enantioselective synthesis of benzo-annulated oxa-heterocycles: scope and limitations". Tetrahedron 64, № 19 (2008): 4162–73. http://dx.doi.org/10.1016/j.tet.2008.03.001.

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27

Buscemi, Silvestre, Andrea Pace, Ivana Pibiri, Nicolò Vivona, and Tullio Caronna. "Fluorinated heterocyclic compounds: an assay on the photochemistry of some fluorinated 1-oxa-2-azoles: an expedient route to fluorinated heterocycles." Journal of Fluorine Chemistry 125, no. 2 (2004): 165–73. http://dx.doi.org/10.1016/j.jfluchem.2003.07.006.

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28

Hossain, Jewel, Ramalingam Natarajan, Ashish K. Banerjee та Swapan Majumdar. "Synthesis of macrocyclic conjugated ψ-disacharides via nitrile oxide cycloaddition: Alkenyl chain length controlled unprecedented formation of di-oxa heterocycles from monosaccharides". Tetrahedron 73, № 22 (2017): 3139–46. http://dx.doi.org/10.1016/j.tet.2017.04.044.

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29

M, Heravi; Majid, M. Malmir, and R. Moradi. "Recent advances in the applications of the intramolecular suzuki cross-coupling reaction in cyclization and heterocyclization: An update." Current Organic Chemistry 23, no. 22 (2019): 2469–88. https://doi.org/10.2174/1385272823666191023115842.

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The palladium-catalyzed reaction of aryl halide and boronic acid for the formation of C–C bonds so-called Suzuki–Miyaura cross-coupling reaction has many applications in Modern Synthetic Organic Chemistry. In 2013, we emphasized the applications of the intramolecular Suzuki cross-coupling reaction in cyclization and heterocyclization. Due to a plethora relevant papers appeared in the chemical literature, herein, we wish to cover by updating our previous review, the applications of the intramolecular Suzuki cross-coupling reaction in cyclization and heterocyclization leading to vari

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30

GOGOI, P. C., M. M. DUTTA, and J. C. S. KATAKY. "ChemInform Abstract: Bridgehead Nitrogen Heterocycles. Part 5. Synthesis of Some 1,3,4-Oxa/ Thiadiazolo(3,2-a)pyrimidin-5-ones, 1,3,4-Oxa/Thiadiazolo(3,2-a)(1,3,5) triazin-7-thiones, 1,3,4-Thiadiazolo(3,2-a)(1,3,5)triazine-5(6H,7H)- thiones, 1,2,4-Triazol." ChemInform 23, no. 4 (2010): no. http://dx.doi.org/10.1002/chin.199204076.

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31

Yong-Yue, Lin, Liang Xiao-Guang Hiu-Kuang Leung та Chan Yuk-Yee. "Ring-size effect in the reaction of α,ω-dibromoalkanes with ethyl acetoacetate and its application to the synthesis of some disubstituted oxa- and aza-heterocycles". Chinese Journal of Chemistry 8, № 2 (1990): 153–59. http://dx.doi.org/10.1002/cjoc.19900080211.

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32

DUITA, M. M., and J. C. S. KATAKY. "ChemInform Abstract: Studies on Biologically Active Heterocycles. Part 5. Synthesis and Biological Activity of Heterocyclic Azadienes and Phosphate/ Thiophosphate Derivatives of 1,3,4-Oxa- and Thiadiazoles (III), (V)." ChemInform 24, no. 51 (2010): no. http://dx.doi.org/10.1002/chin.199351170.

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33

Klärner, Frank-Gerrit, Salih Yaslak, Rolf Drewes, Christoph Gesenberg, and Michael Peter. "Reactivity of cyclopentenyl anion analogous heterocycles: 1,5-electrocyclization of 2-oxa-, 2-thia-, 2-aza- and 2-phosphabicyclo[3.2.0]hept-3-ene. A sigmatropic [1,3] carbon shift." Liebigs Annalen 1995, no. 2 (1995): 203–10. http://dx.doi.org/10.1002/jlac.199519950229.

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34

C. S. Kataky, Jibon, Probin Chandra Gogoi, Mantu Moni Dutta, and Jiban Chandra Sarmah Kataky. "Bridgehead Nitrogen Heterocycles. Part V. Synthesis of Some 1,3,4-Oxa/Thiadiazolo[3,2-a]pyrimidin-5-ones, 1,3,4-Oxa/Thiadiazolo[3,2-a][1,3,5]triazin-7-thiones, 1,3,4-Thiadiazolo[3,2-a][1,3,5]triazine-5(6H,7H)-thiones, 1,2,4-Triazolo[3,4-b][1,3,4]thiadiazine and Thiadiazoles Derivatives." HETEROCYCLES 32, no. 10 (1991): 1897. http://dx.doi.org/10.3987/com-91-5672.

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35

KLAERNER, F. G., S. YASLAK, R. DREWES, C. GESENBERG, and M. PETER. "ChemInform Abstract: Reactivity of Cyclopentenyl Anion Analogous Heterocycles: 1,5- Electrocyclization of 2-Oxa-, 2-Thia-, 2-Aza- and 2-Phosphabicyclo(3.2. 0)hept-3-ene. A Sigmatropic (1,3) Carbon Shift." ChemInform 26, no. 25 (2010): no. http://dx.doi.org/10.1002/chin.199525053.

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36

Qian, Zhiwei, Anjiang Yang, Weiteng An, et al. "An efficient synthesis of novel dibenzoxdiazepine-fused heterocycles through a multicomponent reaction." RSC Adv. 4, no. 92 (2014): 50947–49. http://dx.doi.org/10.1039/c4ra09196e.

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37

Hazarika, J., and J. C. S. Kataky. "ChemInform Abstract: Biologically Active Heterocycles. Part 10. Synthesis of 2-Amino-4- [5-(2-chlorophenyl)-1,3,4-oxa/thiadiazol-2-yl]-6-aryl/substituted aryl-7-oxo-6,7-dihydrothiazolo[4,5-d]pyrimidine-5(H)-thiones as Probable Bioactive Compounds." ChemInform 32, no. 26 (2010): no. http://dx.doi.org/10.1002/chin.200126152.

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38

Bürger, Hans, Thomas Hagen, and Gottfried Pawelke. "Oxa-azonia-boratacyclopentanes by Insertion of Dimethylaminobis(trifluoromethyl)borane into Epoxides." Zeitschrift für Naturforschung B 48, no. 7 (1993): 935–39. http://dx.doi.org/10.1515/znb-1993-0714.

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Dimethylaminobis(trifluoromethyl)borane, (CF3)2BNMe2 (A), reacts with epoxides of the general formula to yield five-membered heterocycles(CF3)2, R = Me (1), CH,F (2), CF3 (3), Et (4), Bz (5). With R = Ph a 1:2 mixture of the isomers (CF3)2O (6a) and (CF3)2 (6b) is obtained. To the contrary, and A form the borane-dimethylamine adduct (H2C=CMe—CH2-O)(CF3)2B • NHMe2 (7). The compounds have been characterized by elemental analyses, multinuclear NMR, IR and mass spectra.

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39

Nagireddy, Jaipal R., Emily Carlson, and William Tam. "1,3-Dipolar cycloadditions of nitrile oxides with 7-oxa- and 7-azabenzonorbornadienes." Canadian Journal of Chemistry 92, no. 7 (2014): 635–39. http://dx.doi.org/10.1139/cjc-2014-0140.

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Dipolar cycloaddition reactions allow for the efficient construction of five-membered heterocycles, often with diverse medicinal applications. We examined the 1,3-dipolar cycloaddition of 7-oxabenzonorbornadienes and 7-azabenzonorbornadienes with acetonitrile oxide and benzonitrile oxide, achieving an assortment of heterobicycle-fused isoxazolines with good to excellent yields. All isoxazolines were consistently directed to the exo face of the bicyclic framework with complete stereoselectivity. Preliminary biological testing of the adducts also showed positive anti-cancer activity, suggesting

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40

Čmelík, Richard, Michal Čajan, Jaromír Marek та Pavel Pazdera. "Syntheses and Structure Study on 3,3aλ4,4-Trithia-1-azapentalenes and Their 3-Oxa Analogues". Collection of Czechoslovak Chemical Communications 68, № 7 (2003): 1243–63. http://dx.doi.org/10.1135/cccc20031243.

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Reactions of nitrile, amide or ester of 5-amino-3-thioxo-3H-1,2-dithiole-4-carboxylic acid 1 with alkylation and acylation agents were studied. "Ionic" 1,2-dithiole amides 6 were formed in several ways. Treatment with phosphorus pentasulfide afforded the corresponding 3,3aλ4,4-trithia-1-azapentalenes 7. Structures of the synthesized heterocycles were studied using a combination of X-ray analysis, IR spectroscopy, and HF and DFT quantum-chemical calculations.

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41

Albano, Gianluigi, and Laura Antonella Aronica. "From Alkynes to Heterocycles through Metal-Promoted Silylformylation and Silylcarbocyclization Reactions." Catalysts 10, no. 9 (2020): 1012. http://dx.doi.org/10.3390/catal10091012.

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Oxygen and nitrogen heterocyclic systems are present in a large number of natural and synthetic compounds. In particular, oxa- and aza-silacyclane, tetrahydrofuran, benzofuran, cycloheptadifuranone, cycloheptadipyrrolone, pyrrolidine, lactone, lactam, phthalan, isochromanone, tetrahydroisoquinolinone, benzoindolizidinone, indoline and indolizidine scaffolds are present in many classes of biologically active molecules. Most of these contain a C=O moiety which can be easily introduced using carbonylative reaction conditions. In this field, intramolecular silylformylation and silylcarbocyclizatio

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42

Deforth, T., M. Kaschke, H. Stock, H. Pritzkow, and W. Siebert. "Synthesis of C2B3 X-Heterocycles (X = C, N, P, O, S) from 1,3,5-Triborapentanes." Zeitschrift für Naturforschung B 52, no. 7 (1997): 823–30. http://dx.doi.org/10.1515/znb-1997-0711.

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Abstract The hydroboration of acetylene with HBCl2 yields the products (Cl2B)2CHMe (1a), (Cl2BCHMe)2BCl (2a), (Cl2BCHMeBCl)2CHMe (3a), and (ClBCHMe)3 (4a). The crystal structure of 4a as well as of the pentaiodo derivative 2b were determined. A mechanism for the formation of the different hydroboration products is proposed. The 1,3,5-triborapentane 2a serves as precursor for the synthesis of derivatives of 1,3,5-triboracyclohexanes, 1,3,5-tribora-2-aza-cyclohexanes, 1,3,5-tribora-2-phospha-cyclo-hexanes, and 1,3,5-tribora-2-thia-cyclohexanes. Their constitutions have been derived from spectros

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43

Racheva, N. L., Z. G. Aliev та A. N. Maslivets. "Five-membered 2,3-dioxo heterocycles: LXI. Reaction of 3-aroyl-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones with α-enamino esters. Crystalline and molecular structure of methyl 11-benzoyl-2-o-hydroxyphenyl-3,4,10-trioxo-6,9-diphenyl-7-oxa-2,9-diazatricyclo[6.2.1.01,5]undec-5-ene-8-carboxylate". Russian Journal of Organic Chemistry 44, № 8 (2008): 1184–88. http://dx.doi.org/10.1134/s1070428008080137.

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Syrota, Natalia O., Sergiy V. Kemskiy, Lesya M. Saliyeva, and Mykhailo V. Vovk. "1,2,3-Triazole-4(5)-amines – Convenient Synthetic Blocks for the Construction of Triazolo-Annulated Heterocycles." Journal of Organic and Pharmaceutical Chemistry 20, no. 2 (2022): 27–51. http://dx.doi.org/10.24959/ophcj.22.258512.

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Aim. To analyze and summarize the synthetic potential of 1,2,3-triazole-4(5)-amines as efficient building blocks in the synthesis of triazolo-annulated pyridine, azine and azepine systems.Results and discussion. Original literature sources revealing the synthetic potential of 4(5)-amino functionalized 1,2,3-triazoles as convenient and available building blocks for the preparation of triazolo-annulated pyridines, azines and azepines were analyzed and systematized. Condensation of 1,2,3-triazole-4(5)-amines with methylene active compounds was shown to be a powerful tool for the synthesis of vers

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Dhameliya, Tejas M., Disha D. Shah, Aayushi C. Shah, et al. "Synthesis of Nitrogen- and Oxygen-Containing Heterocycles Catalysed by Metal Nanoparticles Reported in 2022." Synlett, January 3, 2024. http://dx.doi.org/10.1055/s-0042-1751533.

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AbstractThe versatility of aza- and oxa-heterocyclic compounds has garnered significant attention in recent times. A large number of currently approved pharmaceutical products include nitrogen- and oxygen-containing heterocycles. Recent nanotechnological developments have propelled an upsurge in the applications of nanocatalysis for heterocyclic synthesis. Metal nanoparticles (MNPs) have emerged as promising catalysts for the synthesis of aza- and oxa-heterocycles owing to their unique physicochemical properties. Various MNPs including gold, silver, nickel and palladium have been evaluated for

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Dhameliya, Tejas M., Rutvi J. Patel, Rajvi H. Amin, Dipen K. Sureja, and Kunjan B. Bodiwala. "Comprehensive Review on Metal Nanoparticles Catalyzed Synthesis of Aza- and Oxa-Heterocycles Reported in 2021." Mini-Reviews in Organic Chemistry 19 (August 23, 2022). http://dx.doi.org/10.2174/1570193x19666220823101118.

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Abstract: Among the several heterocyclic compounds, nitrogen and oxygen are predominant heterocycles due to their abundant biological importance. The nanoparticles have demonstrated the excellent catalytic activity under optimum conditions with higher reusability or recyclability and higher yields of synthetic heterocyclic targets. Previously we reviewed the synthesis of aza- and oxa-heterocycles catalyzed by metal nanoparticles (MNPs) in 2009-2019 and published an update of such reports of 2020 on the same subject. With anticipations to the next, the present comprehensive work highlights the

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Hu, Fangzhi, Liang Wang, Peng Wang, et al. "Switchable construction of oxa-heterocycles with diverse ring sizes via chemoselective cyclization controlled by dibrominated compounds." Organic Chemistry Frontiers, 2022. http://dx.doi.org/10.1039/d2qo01273a.

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Gataullin, Rail Rafkatovich, and Nargiza Rustamovna Yamaletdinova. "Advances in the synthesis of heterocycles with two and three heteroatoms using hydrazonoyl halides." Helvetica Chimica Acta, April 30, 2024. http://dx.doi.org/10.1002/hlca.202400058.

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The review covers the results of studies published in the literature on the use of hydrazonoyl halides in the synthesis of five‐ (pyrazoles, thiazoles, triazoles, oxa‐ and thiadiazoles), six‐ (oxa‐ and thiadiazines, indazoles, pyridazines, pyrazines, tetrazines) or seven‐membered (benzotriazepine) heterocycles. In the formation of these heterocycles, the main intermediate stage of the reaction is the in situ generation of nitrilimine, which enters into a cycloaddition reaction with substituted acetylenes (including in situ generated benzynes, naphthynes), allenes, activated olefins, anthranili

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Wang, Fangyuan, Ting Wu, Bin Lu, et al. "Facile and practical access to chiral benzofused oxa-heterocycles via asymmetric hydrogenation and intramolecular SNAr cascade." Organic Chemistry Frontiers, 2024. http://dx.doi.org/10.1039/d3qo01665j.

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Development of efficient protocols for the synthesis of chiral benzofused oxa-heterocycles has attracted tremendous interest due to the ubiquitous presence of these structural motives in numerous bioactive compounds and antibiotics....

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Wagner, Lisa, Jörg Stang, Sebastian Derra, Tim Hollmann, and Frank Hahn. "Towards Understanding Oxygen Heterocycle-Forming Biocatalysts: A Selectivity Study of The Pyran Synthase PedPS7." Organic & Biomolecular Chemistry, 2022. http://dx.doi.org/10.1039/d2ob02064e.

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Intramolecular oxa-Michael addition-catalysing cyclases are widespread in polyketide biosynthetic pathways. Although they have significant potential in biotechnology and chemoenzymatic synthesis of chiral heterocycles, they have only scarcely been studied. Here,...

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