Pub Date : 2025-11-25DOI: 10.1016/j.tet.2025.135069
Wenxue Li , Zhenjie Qi , Zhenyu An , Yinjun Wei , Boyue Lin , Wenxin Chen , Yafeng Liu
An efficient electrochemical oxidation cyclization of 2-vinylanilines and isothiocyanates has been achieved for the synthesis of 2-aminoquinolines via NaI-mediated desulfurative cyclization. The protocol is further characterized by its high yield, broad substrate scope, and operational simplicity. Mechanistic studies reveal that the reaction involves the formation of a thiourea intermediate from 2-vinylanilines and isothiocyanates under electrochemical oxidation.
{"title":"Access to 2-aminoquinolines from 2-vinylanilines and isothiocyanates via electrochemically induced desulfurative cyclization","authors":"Wenxue Li , Zhenjie Qi , Zhenyu An , Yinjun Wei , Boyue Lin , Wenxin Chen , Yafeng Liu","doi":"10.1016/j.tet.2025.135069","DOIUrl":"10.1016/j.tet.2025.135069","url":null,"abstract":"<div><div>An efficient electrochemical oxidation cyclization of 2-vinylanilines and isothiocyanates has been achieved for the synthesis of 2-aminoquinolines <em>via</em> NaI-mediated desulfurative cyclization. The protocol is further characterized by its high yield, broad substrate scope, and operational simplicity. Mechanistic studies reveal that the reaction involves the formation of a thiourea intermediate from 2-vinylanilines and isothiocyanates under electrochemical oxidation.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"191 ","pages":"Article 135069"},"PeriodicalIF":2.2,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-24DOI: 10.1016/j.tet.2025.135070
Karishma Tiwari , Garima Pandey
Covalent organic frameworks (COFs) have rapidly emerged as a versatile class of highly crystalline porous polymers with tunable functionalities showing broad applications in the field of gas storage, catalysis, energy storage, sensing, drug delivery, and hydrogen evolution, etc. Fundamental to COF Chemistry is dynamic covalent chemistry (DCC), which allows error corrections during reversible bond formation to produce well-ordered frameworks. Several named reactions governed by DCC have been exploited for COF synthesis. This review provides a critical evaluation of fundamental reversible boronic acid condensation and key named reactions, including highly reversible Schiff base condensation, as well as reactions with low to moderate reversibility or irreversible nature, particularly Knoevenagel condensation, aldol condensation, Horner–Wadsworth–Emmons (HWE) condensation, Suzuki-type cross-coupling, Sonogashira coupling, and the aza-Diels–Alder reaction. Each of these reactions yields COFs with distinct structures and functionalities determined by the extent of their reaction reversibility. COFs synthesized through reversible condensation exhibit high crystallinity but limited stability, whereas frameworks produced by an irreversible approach show enhanced stability at the expense of crystallinity. Moreover, robustness in COFs can be improved by combining reversible and irreversible reactions or through post-synthetic modifications.
{"title":"The named reaction toolbox for COF synthesis: controlling crystallinity, stability, and performance","authors":"Karishma Tiwari , Garima Pandey","doi":"10.1016/j.tet.2025.135070","DOIUrl":"10.1016/j.tet.2025.135070","url":null,"abstract":"<div><div>Covalent organic frameworks (COFs) have rapidly emerged as a versatile class of highly crystalline porous polymers with tunable functionalities showing broad applications in the field of gas storage, catalysis, energy storage, sensing, drug delivery, and hydrogen evolution, etc. Fundamental to COF Chemistry is dynamic covalent chemistry (DCC), which allows error corrections during reversible bond formation to produce well-ordered frameworks. Several named reactions governed by DCC have been exploited for COF synthesis. This review provides a critical evaluation of fundamental reversible boronic acid condensation and key named reactions, including highly reversible Schiff base condensation, as well as reactions with low to moderate reversibility or irreversible nature, particularly Knoevenagel condensation, aldol condensation, Horner–Wadsworth–Emmons (HWE) condensation, Suzuki-type cross-coupling, Sonogashira coupling, and the aza-Diels–Alder reaction. Each of these reactions yields COFs with distinct structures and functionalities determined by the extent of their reaction reversibility. COFs synthesized through reversible condensation exhibit high crystallinity but limited stability, whereas frameworks produced by an irreversible approach show enhanced stability at the expense of crystallinity. Moreover, robustness in COFs can be improved by combining reversible and irreversible reactions or through post-synthetic modifications.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"191 ","pages":"Article 135070"},"PeriodicalIF":2.2,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145622335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-22DOI: 10.1016/j.tet.2025.135068
Wen Yang , Ziyi Xu , Jiawei Bai , Hongyu Qiu , Zhongzhong Cao , Xin Min , Xuerui Yang , ChangChao Zhan , Qingchun Huang , Jiayan Pan , Zhongxin Li , Lidong Lai , Shaomin Ji
Combining N-iodosuccinimide (NIS) and trifluoroacetic acid (TFA) offers an efficient method for the iodination of a wide range of 3,5-disubstituted isothiazoles at room temperature, as demonstrated in this paper. The results indicate that when the C5 position of isothiazole ring is not the substituent of OCH3Ph, the corresponding C4-mono-iodoisothiazoles are obtained in high yields with excellent regioselectivity, while when the C5 position of isothiazole ring is the substituent of OCH3Ph, the corresponding diiodo and triiodoisothiazoles were synthesized. Additionally, both of bromination and chlorination of 3,5-disubstituted isothiazoles can also occur efficiently. Moreover, the versatility of the method is demonstrated by the iodination of isoxazoles and isoselenazoles.
{"title":"Mild and regioselective iodination of 3,5-disubstituted isothiazoles with N-iodosuccinimide and trifluoroacetic acid","authors":"Wen Yang , Ziyi Xu , Jiawei Bai , Hongyu Qiu , Zhongzhong Cao , Xin Min , Xuerui Yang , ChangChao Zhan , Qingchun Huang , Jiayan Pan , Zhongxin Li , Lidong Lai , Shaomin Ji","doi":"10.1016/j.tet.2025.135068","DOIUrl":"10.1016/j.tet.2025.135068","url":null,"abstract":"<div><div>Combining <em>N</em>-iodosuccinimide (NIS) and trifluoroacetic acid (TFA) offers an efficient method for the iodination of a wide range of 3,5-disubstituted isothiazoles at room temperature, as demonstrated in this paper. The results indicate that when the C5 position of isothiazole ring is not the substituent of OCH<sub>3</sub>Ph, the corresponding C4-mono-iodoisothiazoles are obtained in high yields with excellent regioselectivity, while when the C5 position of isothiazole ring is the substituent of OCH<sub>3</sub>Ph, the corresponding diiodo and triiodoisothiazoles were synthesized. Additionally, both of bromination and chlorination of 3,5-disubstituted isothiazoles can also occur efficiently. Moreover, the versatility of the method is demonstrated by the iodination of isoxazoles and isoselenazoles.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"191 ","pages":"Article 135068"},"PeriodicalIF":2.2,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In 2002, the ground-breaking concept, known as Click Chemistry, was independently presented by Sharpless and Meldal. The reaction involves the advent of Cu(I)-catalyzed Huisgen type 1,3-dipolar cycloaddition known as copper-catalyzed azide-alkyne cycloaddition (CuAAC) to yield the 1,4-disubstituted 1,2,3 triazoles in a regioselective manner. Later on, several other metals such as Ni, Rh, Ir, Zn, Ag etc. are used, and non-metal pathways like the electrochemical method and thermal method have also been developed for the azide-alkyne cycloaddition (AAC). Click chemistry promotes chemical reactions that enable the connection of two species in a simple and selective way, with few or no by-products under mild conditions. The extensive applications of this reaction in several industries have made it a booming research area. Due to the triazole linkage's characteristics as a peptide mimic, this chemistry also facilitates bioconjugation and peptide ligation. Herein, we have summarized all the emerging methodologies developed during 2016–2025 with an enduring description. This review will be very useful to synthetic/medicinal chemists, researchers of materials science, and in the catalysis domains.
{"title":"Metal-catalyzed azide-alkyne cycloaddition-click chemistry: an update (2016–2025)","authors":"Subhasis Samai , Sanghamitra Atta , Maya Shankar Singh","doi":"10.1016/j.tet.2025.135061","DOIUrl":"10.1016/j.tet.2025.135061","url":null,"abstract":"<div><div>In 2002, the ground-breaking concept, known as Click Chemistry, was independently presented by Sharpless and Meldal. The reaction involves the advent of Cu(I)-catalyzed Huisgen type 1,3-dipolar cycloaddition known as copper-catalyzed azide-alkyne cycloaddition (CuAAC) to yield the 1,4-disubstituted 1,2,3 triazoles in a regioselective manner. Later on, several other metals such as Ni, Rh, Ir, Zn, Ag etc. are used, and non-metal pathways like the electrochemical method and thermal method have also been developed for the azide-alkyne cycloaddition (AAC). Click chemistry promotes chemical reactions that enable the connection of two species in a simple and selective way, with few or no by-products under mild conditions. The extensive applications of this reaction in several industries have made it a booming research area. Due to the triazole linkage's characteristics as a peptide mimic, this chemistry also facilitates bioconjugation and peptide ligation. Herein, we have summarized all the emerging methodologies developed during 2016–2025 with an enduring description. This review will be very useful to synthetic/medicinal chemists, researchers of materials science, and in the catalysis domains.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"191 ","pages":"Article 135061"},"PeriodicalIF":2.2,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145622336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-19DOI: 10.1016/j.tet.2025.135056
Nagatoshi Nishiwaki
β-Formyl-β-nitroenamine (FNE), which possesses multiple functionalities, including formyl, amino, and nitro groups, in addition to a CC double bond with biased electron density, exhibits versatile reactivities. The two electrophilic sites react with dinucleophiles to afford nitro-substituted heterocycles. When the nucleophilic amino group and the electrophilic formyl group are reacted, polyfunctionalized pyridines are readily synthesized upon treatment with active methylene compounds. In addition, the biased electron density of the FNE molecule facilitates [4 + 2] or [4 + 4] cycloaddition. FNE is soluble in most organic solvents, is nonexplosive, and can be safely handled. Products with both electron-donating and electron-withdrawing groups are obtained; therefore, the push–pull property of FNE is transcribed to the product. These compounds play a crucial role in the development of optical and electronic materials, giving FNE exceptionally high synthetic utility.
{"title":"β-formyl-β-nitroenamine: A user-friendly synthetic tool with versatile reactivities","authors":"Nagatoshi Nishiwaki","doi":"10.1016/j.tet.2025.135056","DOIUrl":"10.1016/j.tet.2025.135056","url":null,"abstract":"<div><div>β-Formyl-β-nitroenamine (FNE), which possesses multiple functionalities, including formyl, amino, and nitro groups, in addition to a C<img>C double bond with biased electron density, exhibits versatile reactivities. The two electrophilic sites react with dinucleophiles to afford nitro-substituted heterocycles. When the nucleophilic amino group and the electrophilic formyl group are reacted, polyfunctionalized pyridines are readily synthesized upon treatment with active methylene compounds. In addition, the biased electron density of the FNE molecule facilitates [4 + 2] or [4 + 4] cycloaddition. FNE is soluble in most organic solvents, is nonexplosive, and can be safely handled. Products with both electron-donating and electron-withdrawing groups are obtained; therefore, the push–pull property of FNE is transcribed to the product. These compounds play a crucial role in the development of optical and electronic materials, giving FNE exceptionally high synthetic utility.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"191 ","pages":"Article 135056"},"PeriodicalIF":2.2,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145584570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-19DOI: 10.1016/j.tet.2025.135066
Mahesh Vasava , Riya Khandelwal , Chintan Parmar , Shital Thacker , Dhanji P. Rajani , Hitesh D. Patel
In the present study, a series of novel N'-(2-(2-phenyl-1H-benzo[d]imidazole-1-yl)acetyl)isonicotinohydrazide (5a-p) and N'-(2-(1H-benzo[d]imidazole-1-yl)acetyl)isonicotinohydrazide (5'a-d) compounds were synthesized and evaluated for their pharmacological activities, including antibacterial, antitubercular, MDR-TB, and antioxidant properties. The synthesis involved the condensation of ethyl 2-(1H-benzo[d]imidazole-1-yl)acetate (4a-p and 4'a-d) with nicotinic hydrazide. Comprehensive structural analyses, including 1H NMR, 13C NMR, IR, mass spectrometry, and CHN analyses, confirmed the formation of the newly synthesized compounds. The in vitro biological activity assessment revealed that certain compounds exhibited notable activity, as evidenced by their lowest MICs. Additionally, an in-silico computational study was conducted to evaluate the Absorption, Distribution, Metabolism, and Excretion (ADME) pharmacokinetic properties of the compounds. Molecular docking studies against the enoyl-ACP reductase enzyme, utilizing two different Protein Data Bank structures (PDBs: 4TZK and 4TZT), were performed. Moreover, a molecular dynamics study was undertaken to assess the stability of the ligand (5g)-receptor (4TZK) complex. Our findings suggested that these synthesized derivatives have the potential to serve as promising lead molecules for the development of effective antitubercular agents in the future.
{"title":"Design, synthesis, and pharmacological profiling of benzimidazole-based isoniazid analogues: A comprehensive investigation into antitubercular activity, molecular characterization, and computational study","authors":"Mahesh Vasava , Riya Khandelwal , Chintan Parmar , Shital Thacker , Dhanji P. Rajani , Hitesh D. Patel","doi":"10.1016/j.tet.2025.135066","DOIUrl":"10.1016/j.tet.2025.135066","url":null,"abstract":"<div><div>In the present study, a series of novel N'-(2-(2-phenyl-1H-benzo[<em>d</em>]imidazole-1-yl)acetyl)isonicotinohydrazide (<strong>5a-p)</strong> and N'-(2-(1H-benzo[<em>d</em>]imidazole-1-yl)acetyl)isonicotinohydrazide <strong>(5'a-d)</strong> compounds were synthesized and evaluated for their pharmacological activities, including antibacterial, antitubercular, MDR-TB, and antioxidant properties. The synthesis involved the condensation of ethyl 2-(1<em>H</em>-benzo[<em>d</em>]imidazole-1-yl)acetate (<strong>4a-p</strong> and <strong>4'a-d</strong>) with nicotinic hydrazide. Comprehensive structural analyses, including <sup>1</sup>H NMR, <sup>13</sup>C NMR, IR, mass spectrometry, and CHN analyses, confirmed the formation of the newly synthesized compounds. The <em>in vitro</em> biological activity assessment revealed that certain compounds exhibited notable activity, as evidenced by their lowest MICs. Additionally, an <em>in-silico</em> computational study was conducted to evaluate the Absorption, Distribution, Metabolism, and Excretion (ADME) pharmacokinetic properties of the compounds. Molecular docking studies against the enoyl-ACP reductase enzyme, utilizing two different Protein Data Bank structures (<strong>PDBs</strong>: 4TZK and 4TZT), were performed. Moreover, a molecular dynamics study was undertaken to assess the stability of the ligand <strong>(5g)</strong>-receptor (4TZK) complex. Our findings suggested that these synthesized derivatives have the potential to serve as promising lead molecules for the development of effective antitubercular agents in the future.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"190 ","pages":"Article 135066"},"PeriodicalIF":2.2,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-15DOI: 10.1016/j.tet.2025.135065
Aniket Majhi, Samim Sahaji, Anup Kumar Misra
A straightforward synthetic strategy has been developed for the synthesis of the tetrasaccharide containing a β-d-mannose moiety corresponding to the O-specific polysaccharide of Salmonella cerro (S. cerro) O:18 strain. The synthetic strategy involves 1,2-cis glycosylation of a d-mannose unit by H-bond mediated aglycone delivery using judiciously functionalized d-mannose thioglycoside donor. The glycosylation steps were high yielding with satisfactory stereochemistry at the glycosyl linkages.
采用一种简单的合成策略，合成了含有β-d-甘露糖片段的四糖，该四糖片段与沙门氏菌cerro (S. cerro) O:18菌株的O特异性多糖相对应。该合成策略包括利用合理功能化的d-甘露糖硫苷供体，通过氢键介导的苷元传递，将d-甘露糖单元1,2-顺式糖基化。糖基化步骤产率高，在糖基键上具有令人满意的立体化学性质。
{"title":"Synthesis of the β-d-mannose containing tetrasaccharide repeating unit corresponding to the O-specific polysaccharide of Salmonella cerro O:18","authors":"Aniket Majhi, Samim Sahaji, Anup Kumar Misra","doi":"10.1016/j.tet.2025.135065","DOIUrl":"10.1016/j.tet.2025.135065","url":null,"abstract":"<div><div>A straightforward synthetic strategy has been developed for the synthesis of the tetrasaccharide containing a β-<span>d</span>-mannose moiety corresponding to the <em>O</em>-specific polysaccharide of <em>Salmonella cerro</em> (<em>S. cerro</em>) O:18 strain. The synthetic strategy involves 1,2-<em>cis</em> glycosylation of a <span>d</span>-mannose unit by <em>H</em>-bond mediated aglycone delivery using judiciously functionalized <span>d</span>-mannose thioglycoside donor. The glycosylation steps were high yielding with satisfactory stereochemistry at the glycosyl linkages.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"190 ","pages":"Article 135065"},"PeriodicalIF":2.2,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-14DOI: 10.1016/j.tet.2025.135060
Yuanfang Liu , Ruiying Pan , Xinni Xie , Jun Liu , Yuguo Du
A series of novel petrosiol E derivatives were synthesized by divergent strategies starting from readily available d-xylose as the chiral template. The pro-differentiating capacities of these derivatives were evaluated using a differentiation model of rat neuron-like PC12 cells and several derivatives exhibited moderate to significant pro-differentiating capacities. Our study demonstrated that the pro-differentiating capacities of these derivatives were very sensitive to modifications in the side chains, suggesting that the conjugated diyne skeleton and terminal alkyl residue might play important roles in the neuronal differentiation.
{"title":"Design, synthesis, and evaluation of petrosiol E derivatives on neuronal progenitors differentiation","authors":"Yuanfang Liu , Ruiying Pan , Xinni Xie , Jun Liu , Yuguo Du","doi":"10.1016/j.tet.2025.135060","DOIUrl":"10.1016/j.tet.2025.135060","url":null,"abstract":"<div><div>A series of novel petrosiol E derivatives were synthesized by divergent strategies starting from readily available <span>d</span>-xylose as the chiral template. The pro-differentiating capacities of these derivatives were evaluated using a differentiation model of rat neuron-like PC12 cells and several derivatives exhibited moderate to significant pro-differentiating capacities. Our study demonstrated that the pro-differentiating capacities of these derivatives were very sensitive to modifications in the side chains, suggesting that the conjugated diyne skeleton and terminal alkyl residue might play important roles in the neuronal differentiation.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"190 ","pages":"Article 135060"},"PeriodicalIF":2.2,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-14DOI: 10.1016/j.tet.2025.135064
Boris V. Lichitsky, Tatiana A. Kudryavtseva, Ekaterina N. Kudryavtseva
In the present communication we describe the construction of imidazo[4,5-b]indeno[2,1-e]pyridin-9(3H)-one system. The considered method is based on previously unknown multicomponent condensation of 5-aminoimidazoles with diverse aldehydes and 1,3-indandione. Sodium salts of 5-aminoimidazole-4-carboxylic acids were employed as convenient precursors for generation of unstable 5-aminoimidazoles in the reaction mixture. The application of easily available aromatic and heterocyclic aldehydes allowed us to obtain the array of target substituted imidazo[4,5-b]indeno[2,1-e]pyridin-9(3H)-ones. Atom economy, mild experimental conditions and simple isolation of the final products are the advantages of the method. X-ray analysis was utilized for confirmation of structure of one of the prepared imidazo[4,5-b]indeno[2,1-e]pyridin-9(3H)-ones.
{"title":"Straightforward synthesis of imidazo[4,5-b]indeno[2,1-e]pyridin-9(3H)-one framework via multicomponent reaction of 5-aminoimidazoles with aldehydes and 1,3-indandione","authors":"Boris V. Lichitsky, Tatiana A. Kudryavtseva, Ekaterina N. Kudryavtseva","doi":"10.1016/j.tet.2025.135064","DOIUrl":"10.1016/j.tet.2025.135064","url":null,"abstract":"<div><div>In the present communication we describe the construction of imidazo[4,5-<em>b</em>]indeno[2,1-<em>e</em>]pyridin-9(<em>3H)-</em>one system. The considered method is based on previously unknown multicomponent condensation of 5-aminoimidazoles with diverse aldehydes and 1,3-indandione. Sodium salts of 5-aminoimidazole-4-carboxylic acids were employed as convenient precursors for generation of unstable 5-aminoimidazoles in the reaction mixture. The application of easily available aromatic and heterocyclic aldehydes allowed us to obtain the array of target substituted imidazo[4,5-<em>b</em>]indeno[2,1-<em>e</em>]pyridin-9(<em>3H</em>)-ones. Atom economy, mild experimental conditions and simple isolation of the final products are the advantages of the method. X-ray analysis was utilized for confirmation of structure of one of the prepared imidazo[4,5-<em>b</em>]indeno[2,1-<em>e</em>]pyridin-9(<em>3H</em>)-ones.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"190 ","pages":"Article 135064"},"PeriodicalIF":2.2,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-13DOI: 10.1016/j.tet.2025.135063
João Pedro de Albuquerque Souza , Giuliana Pavaneli , Sandra Radžiutė , Caroline Da Ros Montes D'Oca , Vincas Būda , Paulo Henrique Gorgatti Zarbin
The chemical ecology of crane flies (Diptera: Tipulidae) has only recently begun to be elucidated, creating a pressing need for enantiomerically pure standards to support structural identification and functional studies. In a previous investigation, the cuticular hydrocarbons (R)- and (S)-3-methylheneicosane were identified as male-specific components of Tipula autumnalis, with synthetic samples enabling both confirmation of their stereostructures and assessment of biological activity. Laboratory bioassays revealed that the (R)-enantiomer elicited an excitatory response in males, whereas the (S)-enantiomer acted as a repellent. In the present work, we detail the total enantiospecific synthesis of these compounds from methyl (S)-3-hydroxy-2-methylpropionate precursor. The route employs orthogonal protection, Wittig coupling with a C17 fragment, hydrogenation, and terminal one-carbon homologation, providing efficient access to long-chain methyl-branched hydrocarbons with full stereochemical control. This work establishes a robust and generalizable strategy for the synthesis of enantioenriched methyl-branched hydrocarbons and provides sufficient material to support all future chemical and behavioral studies in this species, paving the way for the development of targeted insect management strategies.
{"title":"Enantiospecific syntheses of (R)- and (S)-3-methylheneicosane, male-specific cuticular hydrocarbon of the crane fly Tipula autumnalis (Diptera: Tipulidae)","authors":"João Pedro de Albuquerque Souza , Giuliana Pavaneli , Sandra Radžiutė , Caroline Da Ros Montes D'Oca , Vincas Būda , Paulo Henrique Gorgatti Zarbin","doi":"10.1016/j.tet.2025.135063","DOIUrl":"10.1016/j.tet.2025.135063","url":null,"abstract":"<div><div>The chemical ecology of crane flies (Diptera: Tipulidae) has only recently begun to be elucidated, creating a pressing need for enantiomerically pure standards to support structural identification and functional studies. In a previous investigation, the cuticular hydrocarbons (<em>R</em>)- and (<em>S</em>)-3-methylheneicosane were identified as male-specific components of <em>Tipula autumnalis</em>, with synthetic samples enabling both confirmation of their stereostructures and assessment of biological activity. Laboratory bioassays revealed that the (<em>R</em>)-enantiomer elicited an excitatory response in males, whereas the (<em>S</em>)-enantiomer acted as a repellent. In the present work, we detail the total enantiospecific synthesis of these compounds from methyl (<em>S</em>)-3-hydroxy-2-methylpropionate precursor. The route employs orthogonal protection, Wittig coupling with a C17 fragment, hydrogenation, and terminal one-carbon homologation, providing efficient access to long-chain methyl-branched hydrocarbons with full stereochemical control. This work establishes a robust and generalizable strategy for the synthesis of enantioenriched methyl-branched hydrocarbons and provides sufficient material to support all future chemical and behavioral studies in this species, paving the way for the development of targeted insect management strategies.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"190 ","pages":"Article 135063"},"PeriodicalIF":2.2,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145527168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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