We report a telescopic two‐step synthetic strategy for efficiently constructing [1 H ]‐1,2,3‐triazol‐4‐yl modified phenylalanine conjugates. The method combines Sonogashira coupling and a one‐pot domino reaction involving desilylation, azidation, and click chemistry. This protocol enhances the potential for peptide modification and facilitates the synthesis of polyazide derivatives that can be suitable for dendrimeric cores. This reaction yields good results and provides a scalable route, successfully accommodating a wide range of aromatic and heteroaromatic methyl bromides, while achieving excellent chiral integrity and 100% 1,4‐regioselectivity. We also explored the application of a 1,4‐disubstituted [1 H ]‐1,2,3‐triazol‐4‐yl phenylalanine conjugate as a directing group for C(sp 2 )‐H di‐halogenation.
{"title":"Telescopic Synthesis of Triazol‐4‐yl Modified Phenylalanine Conjugates and Peptide Modification Using a Sonogashira Domino Strategy at Room Temperature","authors":"Karuna Thakare, Aman Singh Barahdia, Rahul Jain","doi":"10.1002/ejoc.202501066","DOIUrl":"https://doi.org/10.1002/ejoc.202501066","url":null,"abstract":"We report a telescopic two‐step synthetic strategy for efficiently constructing [1 <jats:italic>H</jats:italic> ]‐1,2,3‐triazol‐4‐yl modified phenylalanine conjugates. The method combines Sonogashira coupling and a one‐pot domino reaction involving desilylation, azidation, and click chemistry. This protocol enhances the potential for peptide modification and facilitates the synthesis of polyazide derivatives that can be suitable for dendrimeric cores. This reaction yields good results and provides a scalable route, successfully accommodating a wide range of aromatic and heteroaromatic methyl bromides, while achieving excellent chiral integrity and 100% 1,4‐regioselectivity. We also explored the application of a 1,4‐disubstituted [1 <jats:italic>H</jats:italic> ]‐1,2,3‐triazol‐4‐yl phenylalanine conjugate as a directing group for C(sp <jats:sup>2</jats:sup> )‐H di‐halogenation.","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":"117 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146070620","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}
Xifu Liang, Victor Friis, Karolina Agata Szlek, Asger Munk Koue, Jesper Bendix, Lars Skjolding, Sergey Kucheryavskiy, Marco Maschietti, Christian Marcus Pedersen
Michael acceptors derived from biomass resources, such as carbohydrates, have been synthesized and their H 2 S scavenging properties studied. The most promising candidates were compared with the commercial H 2 S scavenger MEA‐triazine by studying the aqueous phase scavenging reactions using in situ Raman spectroscopy and the gas–liquid reactions were evaluated in a flow setup. Based on cost and scavenging efficiency considerations, the industrially most promising candidates were submitted to ecotoxicity studies. We have found three families of Michael acceptors, which are readily available and can be tailor‐made to serve as sulfide scavengers under different conditions.
{"title":"Biomass‐Based H 2 S Scavengers: Michael Acceptors","authors":"Xifu Liang, Victor Friis, Karolina Agata Szlek, Asger Munk Koue, Jesper Bendix, Lars Skjolding, Sergey Kucheryavskiy, Marco Maschietti, Christian Marcus Pedersen","doi":"10.1002/ejoc.202501122","DOIUrl":"https://doi.org/10.1002/ejoc.202501122","url":null,"abstract":"Michael acceptors derived from biomass resources, such as carbohydrates, have been synthesized and their H <jats:sub>2</jats:sub> S scavenging properties studied. The most promising candidates were compared with the commercial H <jats:sub>2</jats:sub> S scavenger MEA‐triazine by studying the aqueous phase scavenging reactions using in situ Raman spectroscopy and the gas–liquid reactions were evaluated in a flow setup. Based on cost and scavenging efficiency considerations, the industrially most promising candidates were submitted to ecotoxicity studies. We have found three families of Michael acceptors, which are readily available and can be tailor‐made to serve as sulfide scavengers under different conditions.","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":"30 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146056030","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}
Lizeth Y. F. Haveman , Albert D. Windhorst , Danielle J. Vugts
The trifluoromethyl (CF3) group is a ubiquitous motif in drug discovery campaigns due to its ability to markedly improve the ADME properties of small molecules while maintaining potency. The isotopologue labeling of CF3‐bearing drugs with fluorine‐18 has gained attention for positron emission tomography (PET) imaging. However, their radiolabeling via conventional 18F‐trifluoromethylation methods relies almost completely on nucleophilic and radical [18F]CF3‐reagents, whereas there remains no general means to incorporate a formal [18F]CF3+ into PET tracer candidates. Herein, we disclose the realization of a novel electrophilic 18F‐labeled trifluoromethylating reagent based on the family of 10‐λ‐3 hypervalent iodines: [18F]Togni reagent I. The method uses nucleophilic ligand substitution at iodine by the [18F]Ruppert–Prakash reagent, providing [18F]Togni reagent I in a radiochemical yield of 4.3 ± 0.8% and a molar activity of 15 ± 9.6 GBq/μmol. Initial studies on the utility of this reagent demonstrate the direct, late‐stage formation of C(sp3)−[18F]CF3 bonds via metallaphotoredox‐mediated conversion of naturally abundant carboxylic acids. Hence, this work illustrates the potential of the novel electrophilic [18F]CF3‐reagent as a complementary approach leading to valuable 18F‐trifluoromethylated architectures in PET tracer development.
{"title":"Synthesis and Application of [18F]Togni Reagent I: An Electrophilic 18F‐Labeled Trifluoromethylating Reagent for Positron Emission Tomography Tracer Synthesis","authors":"Lizeth Y. F. Haveman , Albert D. Windhorst , Danielle J. Vugts","doi":"10.1002/ejoc.202501181","DOIUrl":"10.1002/ejoc.202501181","url":null,"abstract":"<div><div>The trifluoromethyl (CF<sub>3</sub>) group is a ubiquitous motif in drug discovery campaigns due to its ability to markedly improve the ADME properties of small molecules while maintaining potency. The isotopologue labeling of CF<sub>3</sub>‐bearing drugs with fluorine‐18 has gained attention for positron emission tomography (PET) imaging. However, their radiolabeling via conventional <sup>18</sup>F‐trifluoromethylation methods relies almost completely on nucleophilic and radical [<sup>18</sup>F]CF<sub>3</sub>‐reagents, whereas there remains no general means to incorporate a formal [<sup>18</sup>F]CF<sub>3</sub><sup>+</sup> into PET tracer candidates. Herein, we disclose the realization of a novel electrophilic <sup>18</sup>F‐labeled trifluoromethylating reagent based on the family of 10‐λ‐3 hypervalent iodines: [<sup>18</sup>F]Togni reagent I. The method uses nucleophilic ligand substitution at iodine by the [<sup>18</sup>F]Ruppert–Prakash reagent, providing [<sup>18</sup>F]Togni reagent I in a radiochemical yield of 4.3 ± 0.8% and a molar activity of 15 ± 9.6 GBq/μmol. Initial studies on the utility of this reagent demonstrate the direct, late‐stage formation of C(sp<sup>3</sup>)−[<sup>18</sup>F]CF<sub>3</sub> bonds via metallaphotoredox‐mediated conversion of naturally abundant carboxylic acids. Hence, this work illustrates the potential of the novel electrophilic [<sup>18</sup>F]CF<sub>3</sub>‐reagent as a complementary approach leading to valuable <sup>18</sup>F‐trifluoromethylated architectures in PET tracer development.</div></div>","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":"29 4","pages":"Article e202501181"},"PeriodicalIF":2.7,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145796444","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}
We describe a hexafluoroisopropanol (HFIP)‐promoted epoxide ring‐opening cyclization of readily accessible 2‐[(2‐substituted‐1‐naphthyloxy)methyl]‐3‐aryloxiranes, proceeding via a regioselective 7‐endo cyclization at the peri (C8) position of the naphthalene ring. This transformation provides a new class of naphtho[1,8‐bc]oxepine derivatives with complete regio‐ and diastereoselectivity. The C2 substituent on the naphthalene framework, along with the π‐activating aryl group on the epoxide, plays a pivotal role in enabling the reaction. The method operates under mild conditions, tolerates a broad substrate scope, and is readily amenable to gram‐scale synthesis. Moreover, the versatility of this strategy is underscored by its successful extension to the diastereoselective synthesis of oxepino[4,3,2‐cd]indoles.
{"title":"Synthesis of Naphtho[1,8‐bc]oxepines Through an HFIP‐Promoted Peri‐Selective Arene–Epoxide Cyclization","authors":"Jahnabi Das , Abhijit Gogoi , Sajal Kumar Das","doi":"10.1002/ejoc.202501042","DOIUrl":"10.1002/ejoc.202501042","url":null,"abstract":"<div><div>We describe a hexafluoroisopropanol (HFIP)‐promoted epoxide ring‐opening cyclization of readily accessible 2‐[(2‐substituted‐1‐naphthyloxy)methyl]‐3‐aryloxiranes, proceeding via a regioselective 7‐<em>endo</em> cyclization at the <em>peri</em> (C8) position of the naphthalene ring. This transformation provides a new class of naphtho[1,8‐<em>bc</em>]oxepine derivatives with complete regio‐ and diastereoselectivity. The C2 substituent on the naphthalene framework, along with the <em>π</em>‐activating aryl group on the epoxide, plays a pivotal role in enabling the reaction. The method operates under mild conditions, tolerates a broad substrate scope, and is readily amenable to gram‐scale synthesis. Moreover, the versatility of this strategy is underscored by its successful extension to the diastereoselective synthesis of oxepino[4,3,2‐<em>cd</em>]indoles.</div></div>","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":"29 4","pages":"Article e202501042"},"PeriodicalIF":2.7,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145711394","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}
Facile synthetic routes for the conversion of a series of N‐aryl propargylamines to thiazolidin‐2‐imines and formamides are described. A cross‐linked chitosan‐supported copper(II) biocomposite (CS‐PDB@Cu(NO3)2) was employed as a heterogeneous catalyst in a one‐pot multicomponent reaction involving primary amines, formaldehyde, terminal alkynes, and isothiocyanates in toluene, yielding thiazolidin‐2‐imines in moderate to good yields (25%–70%) via N‐aryl propargylamine intermediates. Additionally, N‐formylation of N‐aryl propargylamines using the Vilsmeier reagent afforded formamides in high yields (70%–88%). A total of 20 thiazolidin‐2‐imine derivatives and 22 formamide derivatives were successfully isolated. All isolated products were characterized by 1H and 13C {1H} NMR and HRMS spectroscopy. The CS‐PDB@Cu(NO3)2 biocomposite catalyst was recyclable for up to three catalytic cycles through simple filtration. Reaction intermediates for both transformations were identified by LC‐MS analysis. Furthermore, the structures of two thiazolidin‐2‐imine compounds, 4h and 4t, were unambiguously confirmed by single‐crystal X‐ray crystallography.
{"title":"Copper(II)‐Catalyzed One‐Pot Synthesis of Thiazolidin‐2‐imines and Formamides Using Vilsmeier Reagent","authors":"Jyoti Prabha Kujur , Pritish Rajkumar Moon , Rakesh Ganguly , Devendra Deo Pathak","doi":"10.1002/ejoc.202500917","DOIUrl":"10.1002/ejoc.202500917","url":null,"abstract":"<div><div>Facile synthetic routes for the conversion of a series of <em>N</em>‐aryl propargylamines to thiazolidin‐2‐imines and formamides are described. A cross‐linked chitosan‐supported copper(II) biocomposite (CS‐PDB@Cu(NO<sub>3</sub>)<sub>2</sub>) was employed as a heterogeneous catalyst in a one‐pot multicomponent reaction involving primary amines, formaldehyde, terminal alkynes, and isothiocyanates in toluene, yielding thiazolidin‐2‐imines in moderate to good yields (25%–70%) <em>via N</em>‐aryl propargylamine intermediates. Additionally, <em>N</em>‐formylation of <em>N</em>‐aryl propargylamines using the Vilsmeier reagent afforded formamides in high yields (70%–88%). A total of 20 thiazolidin‐2‐imine derivatives and 22 formamide derivatives were successfully isolated. All isolated products were characterized by <sup>1</sup>H and <sup>13</sup>C {<sup>1</sup>H} NMR and HRMS spectroscopy. The CS‐PDB@Cu(NO<sub>3</sub>)<sub>2</sub> biocomposite catalyst was recyclable for up to three catalytic cycles through simple filtration. Reaction intermediates for both transformations were identified by LC‐MS analysis. Furthermore, the structures of two thiazolidin‐2‐imine compounds, <strong>4h</strong> and <strong>4t</strong>, were unambiguously confirmed by single‐crystal X‐ray crystallography.</div></div>","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":"29 4","pages":"Article e202500917"},"PeriodicalIF":2.7,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731882","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}
A TFA‐catalyzed reaction of fluorene propargylic alcohol with 1,3‐dicarbonyls as nucleophiles, resulting in highly functionalized conjugated diene‐diones appended and propargyl‐substituted 1,3‐dicarbonyl derivatives of fluorenone, has been developed. A plausible mechanism for forming title compounds via allene and propargyl carbocation intermediates has been proposed. On the other hand, the reaction under Lewis acid conditions (BF3OEt2) afforded an unusual spirocyclic product, and a plausible mechanism is provided. The scope and synthetic utility of the synthesized products by reduction and base‐promoted cyclization have also been investigated. Spectroscopic data and single‐crystal XRD of the compounds have been utilized to determine the structure of the products.
{"title":"Diverse Reactivity of 9‐Fluorene Propargylic Alcohol and 1,3‐Dicarbonyls with Bronsted and Lewis Acid Catalysts: Synthesis of Spiro, Conjugated, and 9‐Ethynyl Fluorene Derivatives","authors":"Aravamudhan Subhashini , Ponnusamy Shanmugam","doi":"10.1002/ejoc.202500783","DOIUrl":"10.1002/ejoc.202500783","url":null,"abstract":"<div><div>A TFA‐catalyzed reaction of fluorene propargylic alcohol with 1,3‐dicarbonyls as nucleophiles, resulting in highly functionalized conjugated diene‐diones appended and propargyl‐substituted 1,3‐dicarbonyl derivatives of fluorenone, has been developed. A plausible mechanism for forming title compounds via allene and propargyl carbocation intermediates has been proposed. On the other hand, the reaction under Lewis acid conditions (BF<sub>3</sub>OEt<sub>2</sub>) afforded an unusual spirocyclic product, and a plausible mechanism is provided. The scope and synthetic utility of the synthesized products by reduction and base‐promoted cyclization have also been investigated. Spectroscopic data and single‐crystal XRD of the compounds have been utilized to determine the structure of the products.</div></div>","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":"29 4","pages":"Article e202500783"},"PeriodicalIF":2.7,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731880","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}
Rhodium(III)‐catalyzed C–H activation/annulation reactions of glycal derivatives with alkynes have been developed, providing an efficient approach to structurally diverse pyridone‐ and pyranone‐fused sugar frameworks. The catalytic system of [Cp*RhCl2]2/Ag2CO3 in 1,2‐dichloroethane effectively promoted the annulation to give the pyridone‐fused product. The methodology was applicable to a wide range of glycal‐derived primary and secondary amides as well as carboxylic acids, affording the corresponding annulated sugars in moderate to excellent yields. Remarkably, the carboxylic acid‐based annulation proceeded under mild conditions (40°C–80°C) to give pyranone‐fused derivatives in high yields. The annulated products underwent smooth acidic deprotection to furnish the corresponding triols without decomposition, demonstrating the robustness of the fused heterocyclic frameworks.
{"title":"Rhodium‐Catalyzed Annulation of Glycals With Alkynes via C–H Activation: Synthesis of Pyridone‐ and Pyranone‐Fused Sugar Derivatives","authors":"Takumu Kajimoto , Ryota Yabe , Takahiro Nishimura","doi":"10.1002/ejoc.202501104","DOIUrl":"10.1002/ejoc.202501104","url":null,"abstract":"<div><div>Rhodium(III)‐catalyzed C–H activation/annulation reactions of glycal derivatives with alkynes have been developed, providing an efficient approach to structurally diverse pyridone‐ and pyranone‐fused sugar frameworks. The catalytic system of [Cp*RhCl<sub>2</sub>]<sub>2</sub>/Ag<sub>2</sub>CO<sub>3</sub> in 1,2‐dichloroethane effectively promoted the annulation to give the pyridone‐fused product. The methodology was applicable to a wide range of glycal‐derived primary and secondary amides as well as carboxylic acids, affording the corresponding annulated sugars in moderate to excellent yields. Remarkably, the carboxylic acid‐based annulation proceeded under mild conditions (40°C–80°C) to give pyranone‐fused derivatives in high yields. The annulated products underwent smooth acidic deprotection to furnish the corresponding triols without decomposition, demonstrating the robustness of the fused heterocyclic frameworks.</div></div>","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":"29 4","pages":"Article e202501104"},"PeriodicalIF":2.7,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145759542","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}
The synthesis of disaccharide mimics of Campylobacter jejuni HS:4c capsular polysaccharide, a major pathogen associated with campylobacteriosis, is challenged by the presence of a 1,2‐cis‐β‐linked 6‐deoxy‐d‐ido‐heptopyranoside. Herein, the development of a synthetic route to orthogonally protected d‐ido‐hexo‐ and 6‐deoxy‐d‐ido‐heptopyranosyl donors is reported bearing diverse anomeric leaving groups, which represents, to the best of knowledge, the second direct access to 6‐deoxy‐d‐ido‐heptopyranosides from ido‐configured precursors. These donors were evaluated in intramolecular aglycon delivery (IAD) and intermolecular glycosylation protocols. While IAD enabled complete β‐stereoselectivity with hexosyl donors, it failed with the heptosyl analog. Intermolecular glycosylation provided mixtures of anomers, but the use of a 7‐O‐acetyl‐protected heptosyl donor allowed access to the disaccharide in good yield, with chromatographic separation of the α‐ and β‐anomers. Structural analysis revealed unexpected conformational behavior, with the α‐disaccharide adopting the 1C4 chair conformation. This work establishes a foundation for the synthesis of C. jejuni HS:4c disaccharides and represents a step toward well‐defined sugar‐based vaccines candidates against campylobacteriosis.
空肠弯曲杆菌HS:4c荚膜多糖是一种与弯曲菌病相关的主要病原体，其双糖模拟物的合成受到1,2‐cis‐β‐连接的6‐脱氧‐d‐ido‐heptopyranoside存在的挑战。本文报道了一种具有正交保护的d - ido -己基和6 -脱氧- d - ido -庚基供体的合成途径的发展，这些供体具有不同的端粒离去基，据我们所知，这代表了从ido -构型前体中直接获得6 -脱氧- d - ido -庚基苷的第二种途径。这些供体在分子内糖基传递（IAD）和分子间糖基化方案中进行评估。虽然IAD对己糖基供体具有完全的β -立体选择性，但对庚糖基类似物不起作用。分子间糖基化提供了异头化合物的混合物，但使用7‐O‐乙酰基保护的庚基供体可以通过色谱分离α‐和β‐异头化合物，从而获得高产量的双糖。结构分析揭示了意想不到的构象行为，α‐双糖采用1 c4椅构象。这项工作为空肠梭菌HS:4c双糖的合成奠定了基础，并代表着朝着明确定义的以糖为基础的抗弯曲杆菌病候选疫苗迈出了一步。
{"title":"Intra‐ and Intermolecular Glycosylation of d‐Idopyranosyl and 6‐Deoxy‐d‐ido‐heptopyranosyl Donors: Toward the Repeating Unit of Campylobacter jejuni HS:4c Capsular Polysaccharide","authors":"Maude Cloutier , Nitish Verma , Ilona Douchez , Charles Gauthier","doi":"10.1002/ejoc.202500894","DOIUrl":"10.1002/ejoc.202500894","url":null,"abstract":"<div><div>The synthesis of disaccharide mimics of <em>Campylobacter jejuni</em> HS:4c capsular polysaccharide, a major pathogen associated with campylobacteriosis, is challenged by the presence of a 1,2‐<em>cis</em>‐β‐linked 6‐deoxy‐<span>d</span>‐<em>ido</em>‐heptopyranoside. Herein, the development of a synthetic route to orthogonally protected <span>d</span>‐<em>ido</em>‐hexo‐ and 6‐deoxy‐<span>d</span>‐<em>ido</em>‐heptopyranosyl donors is reported bearing diverse anomeric leaving groups, which represents, to the best of knowledge, the second direct access to 6‐deoxy‐<span>d</span>‐<em>ido</em>‐heptopyranosides from <em>ido</em>‐configured precursors. These donors were evaluated in intramolecular aglycon delivery (IAD) and intermolecular glycosylation protocols. While IAD enabled complete β‐stereoselectivity with hexosyl donors, it failed with the heptosyl analog. Intermolecular glycosylation provided mixtures of anomers, but the use of a 7‐<em>O</em>‐acetyl‐protected heptosyl donor allowed access to the disaccharide in good yield, with chromatographic separation of the α‐ and β‐anomers. Structural analysis revealed unexpected conformational behavior, with the α‐disaccharide adopting the <sup>1</sup><em>C</em><sub>4</sub> chair conformation. This work establishes a foundation for the synthesis of <em>C. jejuni</em> HS:4c disaccharides and represents a step toward well‐defined sugar‐based vaccines candidates against campylobacteriosis.</div></div>","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":"29 4","pages":"Article e202500894"},"PeriodicalIF":2.7,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145718392","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 this review, we explore recent advancements in synthesizingextended aromatic quinoliziniumderivatives via intramolecular aromatic nucleophilic substitution (SNAr) or oxidative 6π‐electrocyclization mechanisms. We first explore their historical synthesis through standard thermal activation and then focus on their synthesis using more efficient and greener activation methods, such as electrosynthesis or photochemical processes. We compare the efficiency of these methods and rationalize through a mechanistic point of view how the choice of leaving groups and substituents on the aromatic backbone affects synthesis outcomes and reaction scope. Finally, we give an overview of the readily accessible quinolizinium skeletons prepared through this intramolecular reaction and explore the current challenges that remain to be addressed to expand their synthetic toolbox.
本文综述了通过分子内亲核取代（S N Ar）或氧化6 π -电环化机制合成扩展芳香喹啉衍生物的最新进展。我们首先通过标准的热活化探索它们的历史合成，然后关注它们的合成使用更有效和更环保的活化方法，如电合成或光化学过程。我们比较了这些方法的效率，并从机理的角度解释了芳香主链上离去基和取代基的选择对合成结果和反应范围的影响。最后，我们概述了通过这种分子内反应制备的易于获取的喹诺嗪骨架，并探讨了当前需要解决的挑战，以扩大其合成工具箱。
{"title":"π‐Expanded Nitrogen‐Cation (N+)‐Doped Polycyclic Aromatic Hydrocarbons: A Review of Intramolecular Cyclization Routes to Benzo[c]Quinolizinium, Triazinium, Pyridoquinazolinium, and Pyridoquinoxalinium Frameworks","authors":"Marine Labro , Cyrille Monnereau , Laure Guy","doi":"10.1002/ejoc.202500429","DOIUrl":"10.1002/ejoc.202500429","url":null,"abstract":"<div><div>In this review, we explore recent advancements in synthesizingextended aromatic quinoliziniumderivatives via intramolecular aromatic nucleophilic substitution (S<sub><em>N</em></sub>Ar) or oxidative 6<em>π</em>‐electrocyclization mechanisms. We first explore their historical synthesis through standard thermal activation and then focus on their synthesis using more efficient and greener activation methods, such as electrosynthesis or photochemical processes. We compare the efficiency of these methods and rationalize through a mechanistic point of view how the choice of leaving groups and substituents on the aromatic backbone affects synthesis outcomes and reaction scope. Finally, we give an overview of the readily accessible quinolizinium skeletons prepared through this intramolecular reaction and explore the current challenges that remain to be addressed to expand their synthetic toolbox.</div></div>","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":"29 4","pages":"Article e202500429"},"PeriodicalIF":2.7,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731879","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}
Wei Zhao , Sining Wang , Haixing Xu , Kun Zhao , Tao Shu
Herein, we described an efficient gold(I)‐catalyzed redox cycloisomerization/[3+2] dipolar cycloaddition domino reaction of o‐(alkynyl)nitrobenzenes. The domino process involves the in situ generation of α‐oxo gold carbenes via intramolecular redox reactions of alkynes and nitro functional groups, followed by the formation of nitrones and subsequent intramolecular [3+2] dipolar cycloaddition reaction to furnish a diverse array of complex isoxazolidine‐containing polycyclic scaffolds in moderate to good yields, with up to excellent diastereoselectivities.
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