Pub Date : 2025-02-18DOI: 10.1016/j.tet.2025.134543
Shuangping Chen , Tong Pan , Qi Jiang , Jia Li , Jinming Chen , Wenbing Sheng
Deep eutectic solvent-promoted substitution of aryl halides with N,N-dimethylformamide (DMF) has been developed in this report. The process was successful obtained a wide range of N,N-dimethylaniline compounds from different substrates in moderate to good yields (52 %–93 %) and exhibited specific regioselectivity in the para position. The possible mechanism to explain the regioselectivity was that the para halogen atom of electron-withdrawing group possessed a less spatial resistance, and the stability of the transition states forming ortho-substituted products was destructed due to the hydrogen bonds between deep eutectic solvent and aryl halides. This work was expected to provide a useful guidance for enhancing nucleophilic substitution reactivity of halogen atoms in the para-position of an electron-withdrawing group.
{"title":"Regioselectivity for nucleophilic substitutions of aryl halides with DMF in deep eutectic solvent","authors":"Shuangping Chen , Tong Pan , Qi Jiang , Jia Li , Jinming Chen , Wenbing Sheng","doi":"10.1016/j.tet.2025.134543","DOIUrl":"10.1016/j.tet.2025.134543","url":null,"abstract":"<div><div>Deep eutectic solvent-promoted substitution of aryl halides with <em>N</em>,<em>N</em>-dimethylformamide (DMF) has been developed in this report. The process was successful obtained a wide range of <em>N</em>,<em>N</em>-dimethylaniline compounds from different substrates in moderate to good yields (52 %–93 %) and exhibited specific regioselectivity in the <em>para</em> position. The possible mechanism to explain the regioselectivity was that the <em>para</em> halogen atom of electron-withdrawing group possessed a less spatial resistance, and the stability of the transition states forming <em>ortho</em>-substituted products was destructed due to the hydrogen bonds between deep eutectic solvent and aryl halides. This work was expected to provide a useful guidance for enhancing nucleophilic substitution reactivity of halogen atoms in the <em>para</em>-position of an electron-withdrawing group.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"176 ","pages":"Article 134543"},"PeriodicalIF":2.1,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454057","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}
Herein, we report the use of methanol, a renewable, cost-effective, and easily handled reagent, for the highly selective N-methylation of amides under mild conditions. The reaction is catalyzed by a well-defined Mn-PNP pincer complex and proceeds via the borrowing hydrogen strategy (BHS). This method exhibits broad functional group tolerance and utilizes methanol as a methylating agent, demonstrating exceptional monoselectivity for amides, which enhances its practical appeal. Additionally, a series of control experiments were conducted to provide deeper mechanistic insights into the transformation.
{"title":"Efficient N-methylation of primary amides using methanol under Mn(I)-catalysis","authors":"Reshma Babu , Smruti Rekha Padhy , Ekambaram Balaraman","doi":"10.1016/j.tet.2025.134535","DOIUrl":"10.1016/j.tet.2025.134535","url":null,"abstract":"<div><div>Herein, we report the use of methanol, a renewable, cost-effective, and easily handled reagent, for the highly selective <em>N</em>-methylation of amides under mild conditions. The reaction is catalyzed by a well-defined Mn-PNP pincer complex and proceeds <em>via</em> the borrowing hydrogen strategy (BHS). This method exhibits broad functional group tolerance and utilizes methanol as a methylating agent, demonstrating exceptional monoselectivity for amides, which enhances its practical appeal. Additionally, a series of control experiments were conducted to provide deeper mechanistic insights into the transformation.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"176 ","pages":"Article 134535"},"PeriodicalIF":2.1,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480405","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 : 2025-02-15DOI: 10.1016/j.tet.2025.134541
Yuanqiong Lin , Xiao Zhang , Xiaoshang Zhong , Chunlin Lu , Yinghua Lu , Xin Li , Song Tu
Donor-Acceptor (D-A) type self-assembled molecules (SAMs) are regarded as star organic small molecules that can effectively alleviate the undesired NiOx/perovskite interface problem and demonstrate exceptional hole extraction and transport ability. However, the structure-performance relationships of donor units or anchoring groups of suitable D-A SAMs have not been unveiled. Here, we try to discuss such structure-performance relationships by designing and synthesizing a series of D-A type SAMs (TQB, DQB, DQC and DQP), which incorporate dibenzofurans-substituted bis(4-methoxyphenyl)amine or methoxy triphenylamine as donor unit, quinoxaline as acceptor unit, and phenylboronic acid or benzoic acid or phenylphosphinic acid as anchoring group. Among them, DQB, a dibenzofurans-substituted phenylboronic acid derivative, has unique advantages in terms of thermal stability, interface contact and hole extraction. For different donors, the relevant test and characterization results make clear that the donor with a larger rigid plane building block in SAMs not only enhances thermal stability and electron-donating capability of the SAMs, but also induces high-quality perovskite films. Furthermore, methoxy on the more electron-rich terminal group better passivates perovskite defects. As an anchoring group of D-A type SAMs, the mildly acidic boronic acid group can form the strongest B–O–Ni bond. It stands to reason that unacceptable interfacial reactions and recombination are suppressed. Consequently, the power conversion efficiency of 17.88 % generated by NiOx/DQB-based p-i-n flexible perovskite solar cells is superior to that of other devices. Our results offer a reference for the design of SAMs with better performance.
{"title":"Construction of novel Donor-Acceptor type self-assembled molecules together with NiOx for flexible perovskite solar cells","authors":"Yuanqiong Lin , Xiao Zhang , Xiaoshang Zhong , Chunlin Lu , Yinghua Lu , Xin Li , Song Tu","doi":"10.1016/j.tet.2025.134541","DOIUrl":"10.1016/j.tet.2025.134541","url":null,"abstract":"<div><div>Donor-Acceptor (D-A) type self-assembled molecules (SAMs) are regarded as star organic small molecules that can effectively alleviate the undesired NiO<sub>x</sub>/perovskite interface problem and demonstrate exceptional hole extraction and transport ability. However, the structure-performance relationships of donor units or anchoring groups of suitable D-A SAMs have not been unveiled. Here, we try to discuss such structure-performance relationships by designing and synthesizing a series of D-A type SAMs (<strong>TQB</strong>, <strong>DQB</strong>, <strong>DQC</strong> and <strong>DQP</strong>), which incorporate dibenzofurans-substituted bis(4-methoxyphenyl)amine or methoxy triphenylamine as donor unit, quinoxaline as acceptor unit, and phenylboronic acid or benzoic acid or phenylphosphinic acid as anchoring group. Among them, <strong>DQB</strong>, a dibenzofurans-substituted phenylboronic acid derivative, has unique advantages in terms of thermal stability, interface contact and hole extraction. For different donors, the relevant test and characterization results make clear that the donor with a larger rigid plane building block in SAMs not only enhances thermal stability and electron-donating capability of the SAMs, but also induces high-quality perovskite films. Furthermore, methoxy on the more electron-rich terminal group better passivates perovskite defects. As an anchoring group of D-A type SAMs, the mildly acidic boronic acid group can form the strongest B–<em>O</em>–Ni bond. It stands to reason that unacceptable interfacial reactions and recombination are suppressed. Consequently, the power conversion efficiency of 17.88 % generated by NiO<sub>x</sub>/<strong>DQB</strong>-based p-i-n flexible perovskite solar cells is superior to that of other devices. Our results offer a reference for the design of SAMs with better performance.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"176 ","pages":"Article 134541"},"PeriodicalIF":2.1,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480462","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 : 2025-02-14DOI: 10.1016/j.tet.2025.134538
Honoka Hanashiro, Yuta Ito, Yasufumi Fuchi, Yoshiyuki Hari
Recently, we developed oligonucleotides (ONs) containing syn-constrained 8,1′-ethano-2′-deoxyadenosine. In this study, we further explored the synthesis of 8,1′-ethano-2′-deoxyguanosine (ethano-dG) and 8,1′-ethano-2′-deoxyinosine (ethano-dI). Although ethano-dG could not be synthesized, ethano-dI, in which the inosine (ethI) base was fixed in syn conformation, was successfully synthesized and incorporated into ONs. Subsequently, duplex-forming ability of ethano-dI-containing ONs was evaluated using ultraviolet (UV) melting experiments. Antiparallel Watson–Crick duplex containing the ethI:guanine base pair showed higher thermal stability than those containing other ethI:X base pairs (X = adenine, cytosine, or thymine) due to the formation of two Hoogsteen-type hydrogen bonds between ethI and guanine base at the Watson–Crick side. Although parallel Hoogsteen duplex formation generally requires acidic conditions, ethano-dI-containing ONs formed a parallel Hoogsteen duplex with the complementary DNA under neutral conditions, indicating that ethI stably recognized the cytosine base via two Watson–Crick-type hydrogen bonds. Overall, our findings suggest ethano-dI as a useful material to elucidate the biological functions of syn-oriented purine nucleosides in DNA.
{"title":"Synthesis of 8,1′-ethano-2′-deoxyinosine-containing oligonucleotides, and their antiparallel Watson–Crick and parallel Hoogsteen duplex-forming abilities","authors":"Honoka Hanashiro, Yuta Ito, Yasufumi Fuchi, Yoshiyuki Hari","doi":"10.1016/j.tet.2025.134538","DOIUrl":"10.1016/j.tet.2025.134538","url":null,"abstract":"<div><div>Recently, we developed oligonucleotides (ONs) containing <em>syn</em>-constrained 8,1′-ethano-2′-deoxyadenosine. In this study, we further explored the synthesis of 8,1′-ethano-2′-deoxyguanosine (ethano-dG) and 8,1′-ethano-2′-deoxyinosine (ethano-dI). Although ethano-dG could not be synthesized, ethano-dI, in which the inosine (<sup>eth</sup>I) base was fixed in <em>syn</em> conformation, was successfully synthesized and incorporated into ONs. Subsequently, duplex-forming ability of ethano-dI-containing ONs was evaluated using ultraviolet (UV) melting experiments. Antiparallel Watson–Crick duplex containing the <sup>eth</sup>I:guanine base pair showed higher thermal stability than those containing other <sup>eth</sup>I:X base pairs (X = adenine, cytosine, or thymine) due to the formation of two Hoogsteen-type hydrogen bonds between <sup>eth</sup>I and guanine base at the Watson–Crick side. Although parallel Hoogsteen duplex formation generally requires acidic conditions, ethano-dI-containing ONs formed a parallel Hoogsteen duplex with the complementary DNA under neutral conditions, indicating that <sup>eth</sup>I stably recognized the cytosine base via two Watson–Crick-type hydrogen bonds. Overall, our findings suggest ethano-dI as a useful material to elucidate the biological functions of <em>syn</em>-oriented purine nucleosides in DNA.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"175 ","pages":"Article 134538"},"PeriodicalIF":2.1,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437308","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 : 2025-02-14DOI: 10.1016/j.tet.2025.134540
Anushree Poddar , F. Christopher Pigge
Three palladium(II) complexes supported by new neutral η1-C-donor ligands derived from alkylidene dihydropyridine derivatives are reported. The ligand frameworks are easily constructed from simple 4-alkylpyridines. The ligands feature peripheral aryl sulfonyl groups that increase acidity of picolyl C–H bonds, facilitate subsequent generation of relatively stable alkylidene dihydropyridines, and provide sites for attachment of additional metal ligating groups. Sulfonyl-stabilized alkylidene dihydropyridines readily coordinate PdCl2 through the picolyl carbon in monodentate fashion or as C,N-chelating ligands when 2-pyridylsulfonyl groups are present. All complexes are air-stable and X-ray crystal structures of two complexes are reported. One Pd(II) complex was screened for catalytic activity and found to be moderately effective in mediating Suzuki cross-coupling reactions.
{"title":"Sulfonyl-stabilized 4-alkylidene dihydropyridines as C-donor ligands in organotransition metal catalysis: Synthesis of palladium complexes","authors":"Anushree Poddar , F. Christopher Pigge","doi":"10.1016/j.tet.2025.134540","DOIUrl":"10.1016/j.tet.2025.134540","url":null,"abstract":"<div><div>Three palladium(II) complexes supported by new neutral η<sup>1</sup>-C-donor ligands derived from alkylidene dihydropyridine derivatives are reported. The ligand frameworks are easily constructed from simple 4-alkylpyridines. The ligands feature peripheral aryl sulfonyl groups that increase acidity of picolyl C–H bonds, facilitate subsequent generation of relatively stable alkylidene dihydropyridines, and provide sites for attachment of additional metal ligating groups. Sulfonyl-stabilized alkylidene dihydropyridines readily coordinate PdCl<sub>2</sub> through the picolyl carbon in monodentate fashion or as C,N-chelating ligands when 2-pyridylsulfonyl groups are present. All complexes are air-stable and X-ray crystal structures of two complexes are reported. One Pd(II) complex was screened for catalytic activity and found to be moderately effective in mediating Suzuki cross-coupling reactions.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"175 ","pages":"Article 134540"},"PeriodicalIF":2.1,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437309","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 : 2025-02-13DOI: 10.1016/j.tet.2025.134536
Zhengjia Shen , Jiani Wei , Xue Hu , Zimu Gu , Qiqi Shao , Xuan Chen , Mingming Wang , Dongliang Zhang
A novel ligand-to-metal charge transfer (LMCT)-based synthetic methodology is presented for the decarboxylative hydrogenation of aromatic carboxylic acids. This approach features mild reaction conditions, economical copper-mediated catalysis, and exceptional functional group tolerance. The study addresses significant challenges in aromatic carboxylic acid transformations and underscores the potential of photochemical copper catalysis in contemporary organic synthesis.
{"title":"Photoinduced ligand-to-copper charge transfer for decarboxylative hydrogenation of aromatic carboxylic acids","authors":"Zhengjia Shen , Jiani Wei , Xue Hu , Zimu Gu , Qiqi Shao , Xuan Chen , Mingming Wang , Dongliang Zhang","doi":"10.1016/j.tet.2025.134536","DOIUrl":"10.1016/j.tet.2025.134536","url":null,"abstract":"<div><div>A novel ligand-to-metal charge transfer (LMCT)-based synthetic methodology is presented for the decarboxylative hydrogenation of aromatic carboxylic acids. This approach features mild reaction conditions, economical copper-mediated catalysis, and exceptional functional group tolerance. The study addresses significant challenges in aromatic carboxylic acid transformations and underscores the potential of photochemical copper catalysis in contemporary organic synthesis.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"175 ","pages":"Article 134536"},"PeriodicalIF":2.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437269","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 : 2025-02-13DOI: 10.1016/j.tet.2025.134537
Samim Sahaji, Abhijit Rana, Anup Kumar Misra
Synthesis of the pentasaccharide corresponding to the K116 capsular polysaccharide of Acinetobacter baumannii (A. baumannii) has been achieved using a concise [3 + 2] stereoselective block synthetic strategy. A trisaccharide acceptor was synthesized by sequential stereoselective glycosylations of judiciously functionalized monosaccharide intermediates and a disaccharide was prepared using a thioglycoside derivative as glycosyl acceptor. Beta-linked glycosylations were achieved using thioglycoside as glycosyl donor and a combination of N-iodosuccinimide (NIS) and trifluoromethanesulfonic acid (TfOH) as thiophilic activator. Alpha linked glycosyl linkage was achieved using thioglycoside as donor in the presence of a combination of copper(II) bromide and tetra-n-butylammonium bromide (TBAB) in a mixture of 1,2-dichloroethane and dimethyl formamide (DMF). The yields of the glycosylation reactions were very good with satisfactory stereochemistry at the glycosyl linkages.
{"title":"Convergent synthesis of the pentasaccharide repeating unit of the cell wall K116 capsular polysaccharide of Acinetobacter baumannii","authors":"Samim Sahaji, Abhijit Rana, Anup Kumar Misra","doi":"10.1016/j.tet.2025.134537","DOIUrl":"10.1016/j.tet.2025.134537","url":null,"abstract":"<div><div>Synthesis of the pentasaccharide corresponding to the K116 capsular polysaccharide of <em>Acinetobacter baumannii</em> (<em>A. baumannii</em>) has been achieved using a concise [3 + 2] stereoselective block synthetic strategy. A trisaccharide acceptor was synthesized by sequential stereoselective glycosylations of judiciously functionalized monosaccharide intermediates and a disaccharide was prepared using a thioglycoside derivative as glycosyl acceptor. Beta-linked glycosylations were achieved using thioglycoside as glycosyl donor and a combination of <em>N</em>-iodosuccinimide (NIS) and trifluoromethanesulfonic acid (TfOH) as thiophilic activator. Alpha linked glycosyl linkage was achieved using thioglycoside as donor in the presence of a combination of copper(II) bromide and tetra-<em>n</em>-butylammonium bromide (TBAB) in a mixture of 1,2-dichloroethane and dimethyl formamide (DMF). The yields of the glycosylation reactions were very good with satisfactory stereochemistry at the glycosyl linkages.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"176 ","pages":"Article 134537"},"PeriodicalIF":2.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454058","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 : 2025-02-11DOI: 10.1016/j.tet.2025.134471
Víctor Manuel Pérez-Piña , Rubén Oswaldo Argüello-Velasco , Mario Ordoñez , Ivan Romero-Estudillo
Herein, we report the synthesis of novel 2-alkyl and 2-aryl substituted 4-phosphorylated oxazolines. The synthesis involves a one-pot cyclization reaction between dimethyl (±)-phosphoserinate and several imidate derivatives, prepared under Pinner reaction conditions. This approach produced 2-phenyl and 2-(p-methoxyphenyl) phosphorylated oxazolines and 2-alkyl substituted oxazolines, including a cyclopropyl derivative in good yields. Oxidation of the 2-phenyl phosphorylated oxazoline using DDQ led to the formation of the corresponding phosphorylated oxazole. This method can be easily extended to a wide variety of imidates with different substituents and also offers a practical and versatile approach for advancing research in azaheterocyclic phosphonates.
{"title":"Synthesis of novel 2-alkyl and 2-aryl 4-phosphorylated oxazolines from dimethyl (±)-phosphoserinate","authors":"Víctor Manuel Pérez-Piña , Rubén Oswaldo Argüello-Velasco , Mario Ordoñez , Ivan Romero-Estudillo","doi":"10.1016/j.tet.2025.134471","DOIUrl":"10.1016/j.tet.2025.134471","url":null,"abstract":"<div><div>Herein, we report the synthesis of novel 2-alkyl and 2-aryl substituted 4-phosphorylated oxazolines. The synthesis involves a one-pot cyclization reaction between dimethyl (±)-phosphoserinate and several imidate derivatives, prepared under Pinner reaction conditions. This approach produced 2-phenyl and 2-(<em>p</em>-methoxyphenyl) phosphorylated oxazolines and 2-alkyl substituted oxazolines, including a cyclopropyl derivative in good yields. Oxidation of the 2-phenyl phosphorylated oxazoline using DDQ led to the formation of the corresponding phosphorylated oxazole. This method can be easily extended to a wide variety of imidates with different substituents and also offers a practical and versatile approach for advancing research in azaheterocyclic phosphonates.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"176 ","pages":"Article 134471"},"PeriodicalIF":2.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474021","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 : 2025-02-11DOI: 10.1016/j.tet.2025.134532
Al-Shimaa Badran, Magdy A. Ibrahim, Mai A. Mostafa
Reaction of 4-hydroxy-6-methyl-3-nitro-2H-pyrano[3,2-c]quinoline-2,5(6H)-dione (1) with some primary amines namely methylamine, ethylamine, propylamine, n-butylamine, benzylamine and furfurylamine in molar ratio 1:2, in boiling DMF afforded the unexpected 1-methyl-4-substitutedamino-2-oxo-1,2-dihydroquinoline-3-carboxylic acids. The suggested mechanism was typically described. Structures of the synthesized were clearly confirmed using spectroscopic and elemental analysis.
{"title":"Unusual transformation of 4-hydroxy-6-methyl-3-nitro-2H-pyrano[3,2-c]quinoline-2,5(6H)-dione into 1-methyl-4-substituted amino-2-oxo-1,2-dihydroquinoline-3-carboxylic acids","authors":"Al-Shimaa Badran, Magdy A. Ibrahim, Mai A. Mostafa","doi":"10.1016/j.tet.2025.134532","DOIUrl":"10.1016/j.tet.2025.134532","url":null,"abstract":"<div><div>Reaction of 4-hydroxy-6-methyl-3-nitro-2<em>H</em>-pyrano[3,2-<em>c</em>]quinoline-2,5(6<em>H</em>)-dione (<strong>1</strong>) with some primary amines namely methylamine, ethylamine, propylamine, <em>n</em>-butylamine, benzylamine and furfurylamine in molar ratio 1:2, in boiling DMF afforded the unexpected 1-methyl-4-substitutedamino-2-oxo-1,2-dihydroquinoline-3-carboxylic acids. The suggested mechanism was typically described. Structures of the synthesized were clearly confirmed using spectroscopic and elemental analysis.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"175 ","pages":"Article 134532"},"PeriodicalIF":2.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143396261","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 : 2025-02-10DOI: 10.1016/j.tet.2025.134524
Arina Y. Obydennik, Alexander A. Titov, Anna V. Listratova, Alexey V. Varlamov
Five-, six- and seven-membered carbo- and heterocycles are widespread in nature, and their tricyclic combinations can form a broad spectrum of complex molecules exhibiting unique properties. In the present review we have covered the known synthetic approaches towards tricyclic pyrrolobenzazepine derivatives with a nodal nitrogen atom and described some of their biological activities. Herein, we present systematized information on four skeletally isomeric scaffolds: pyrrolo[2,1-b][3]benzazepines, pyrrolo[1,2-b][2]benzazepines, pyrrolo[2,1-a][2]benzazepines, and pyrrolo[1,2-a][1]benzazepines.
{"title":"Chemical diversity of pyrrolobenzazepine derivatives with a nodal nitrogen atom","authors":"Arina Y. Obydennik, Alexander A. Titov, Anna V. Listratova, Alexey V. Varlamov","doi":"10.1016/j.tet.2025.134524","DOIUrl":"10.1016/j.tet.2025.134524","url":null,"abstract":"<div><div>Five-, six- and seven-membered carbo- and heterocycles are widespread in nature, and their tricyclic combinations can form a broad spectrum of complex molecules exhibiting unique properties. In the present review we have covered the known synthetic approaches towards tricyclic pyrrolobenzazepine derivatives with a nodal nitrogen atom and described some of their biological activities. Herein, we present systematized information on four skeletally isomeric scaffolds: pyrrolo[2,1-<em>b</em>][3]benzazepines, pyrrolo[1,2-<em>b</em>][2]benzazepines, pyrrolo[2,1-<em>a</em>][2]benzazepines, and pyrrolo[1,2-<em>a</em>][1]benzazepines.</div></div>","PeriodicalId":437,"journal":{"name":"Tetrahedron","volume":"176 ","pages":"Article 134524"},"PeriodicalIF":2.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465105","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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