{"title":"Annulation Methods toward the Total Synthesis of Thermorubin: Construction of the AB and BCD Ring Systems.","authors":"Zachary A Kohanov, Andrew N Lowell","doi":"10.1021/acs.joc.5c01129","DOIUrl":"https://doi.org/10.1021/acs.joc.5c01129","url":null,"abstract":"<p><p>New antibiotics are desperately needed to fight the growing threat of antimicrobial resistance. Thermorubin, a forgotten natural product, is one such candidate, as it binds to a novel site on the ribosome and uniquely disrupts both elongation and termination during protein synthesis. In this study, we report the synthesis of the AB and BCD ring portions of thermorubin in a 10% yield over six steps and an 8.9% yield over seven steps, respectively. The key disconnection for both systems involved identification of a symmetric nucleophilic donor synthon suitable for annulation with Michael acceptors within the core tetracycle─an unusual planar aromatic system. An activated form of this symmetric intermediate enabled a formal [4 + 2] cycloaddition with a 6-carboxy pyrone as well as traditional α-β-unsaturated ketones. Beyond advancing the total synthesis of thermorubin, these strategies offer broader utility for the construction of other complex heterocycles.</p>","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144726042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexander I Wright, Chenxi Zhang, Jing Cao, Yuji Nakano, Lucia Sánchez-Jiménez, Julia DeBono, Sankeert Kapatkar, Gregory L Challis, David W Lupton
{"title":"Phosphine-Mediated (3 + 2) Cycloaddition of Electron-Poor Terminal Alkynes: A Concise Route to Premethylenomycin C Lactone.","authors":"Alexander I Wright, Chenxi Zhang, Jing Cao, Yuji Nakano, Lucia Sánchez-Jiménez, Julia DeBono, Sankeert Kapatkar, Gregory L Challis, David W Lupton","doi":"10.1021/acs.joc.5c01179","DOIUrl":"https://doi.org/10.1021/acs.joc.5c01179","url":null,"abstract":"<p><p>Herein, we report a (3 + 2) cycloaddition to deliver an array of cyclopentenes. Typically, the reaction involves electron-poor terminal alkynes and ketomalonate partners; however, numerous structural modifications to the coupling partners have been accommodated to enable 45 examples of the reaction to be completed. Mechanistic studies highlight the role of slow alkyne addition to avoid undesired alkyne deprotonation. Application to the synthesis of premethylenomycin C lactone, an intermediate in methylenomycin biosynthesis with potent activity against Gram-positive bacteria, demonstrates the robust nature and good scalability of the reaction.</p>","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144726043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhouting Zeng,Peng Huang,Weishuang Li,Huaixin Wei,Wenke Wang,Huimei Zhong,Mingming Yu,Zi Yang,Jinhui Cai
{"title":"Electrochemical Synthesis of 2-Selenylnaphthalenes with Alkynyl Alkyl Alcohols and Diselenides.","authors":"Zhouting Zeng,Peng Huang,Weishuang Li,Huaixin Wei,Wenke Wang,Huimei Zhong,Mingming Yu,Zi Yang,Jinhui Cai","doi":"10.1021/acs.joc.5c01136","DOIUrl":"https://doi.org/10.1021/acs.joc.5c01136","url":null,"abstract":"Herein, the facile synthesis of 2-selenylnaphthalene derivatives under mild conditions is accessible via electrocatalytic sequential selenylation/cyclization/aromatization of readily available starting material, which is successfully demonstrated. The potential synthetic utility of this method is demonstrated by its wide substrate scope, excellent functional group compatibility, high efficiency, metal-free, chemical-oxidant-free, easy operation, and easy scalability. The detailed mechanistic experiments indicate that this strategy possibly proceeds via a radical pathway.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"97 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144720237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pan Gao,Xiangchuan Xiu,Zijia Han,Xiaohuan Sun,Guodong Zhang,Jiahang Lv,Yu Yuan,Feng Chen
{"title":"Piezoelectric-Driven Mechanochemical Halogenation: A Transformative Pathway for Sustainable Sandmeyer Reactions via Ball Milling.","authors":"Pan Gao,Xiangchuan Xiu,Zijia Han,Xiaohuan Sun,Guodong Zhang,Jiahang Lv,Yu Yuan,Feng Chen","doi":"10.1021/acs.joc.5c01165","DOIUrl":"https://doi.org/10.1021/acs.joc.5c01165","url":null,"abstract":"The Sandmeyer reaction is a key method for synthesizing aryl halides but often requires complex procedures and large solvent volumes. This study introduces a mechanoredox system using ball milling to activate piezoelectric BaTiO3, enabling solvent-minimized, metal-catalyst-free halogenation of aryl diazonium salts under air. The method features a broad substrate scope, scalability, and recyclable piezoelectric materials without significant activity loss. This sustainable approach overcomes the limitations of traditional Sandmeyer reactions, providing an efficient and practical alternative for aryl halide synthesis.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"93 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144720279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Nitrogen-Centered Radical Cyclization Initiated by Proton-Coupled Electron Transfer: A Mechanistic Study of 5-Exo-trig and 6-Endo-trig Cyclization Pathways.","authors":"Yu-Qi Tang,Ming-Tian Zhang,Lei Jiao","doi":"10.1021/acs.joc.5c01102","DOIUrl":"https://doi.org/10.1021/acs.joc.5c01102","url":null,"abstract":"Nitrogen-containing heterocycles are key structural motifs in bioactive molecules and materials, which could be synthesized by the intramolecular cyclization of nitrogen-centered radicals. In this study, the cyclization selectivity of nitrogen-centered radical reactions in ene-amide substrates initiated by proton-coupled electron transfer (PCET) under photoredox catalytic conditions is investigated. Contrary to prior knowledge that the 5-exo-trig/6-endo-trig cyclization selectivity could be switched by a phenyl tether, our experimental and computational analyses demonstrate that 5-exo-trig cyclization dominates, yielding γ-lactams as major products, while 6-endo-trig pathways are disfavored unless specific substituents (e.g., α-phenyl or sulfonamide groups) modulate reactivity. These findings complement the established conceptions of radical cyclization of ene-amide substrates and offer novel strategies for synthesizing functionalized lactams.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"24 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144720286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jia-Wei Li,Yu-Yan Tan,Xiao-Hong Chen,Han Yang,Jin-Lei Wang,Yue-Jin Liu
{"title":"Cobalt(II)-Catalyzed [4 + 2] Annulation of Indolecarboxamides with Alkenes for Regioselective Synthesis of γ-Carbolinones.","authors":"Jia-Wei Li,Yu-Yan Tan,Xiao-Hong Chen,Han Yang,Jin-Lei Wang,Yue-Jin Liu","doi":"10.1021/acs.joc.5c00989","DOIUrl":"https://doi.org/10.1021/acs.joc.5c00989","url":null,"abstract":"We report a cobalt-catalyzed cascade [4 + 2] annulation of the C(sp2)-H/N-H bonds in indolecarboxamides with alkenes, facilitated by an 8-aminoquinoline directing group. This reaction represents the first example employing simple olefins as substrates to directly construct the γ-carbolinone motif. Furthermore, it exhibits broad substrate scope and excellent regioselectivity, achieving high yields with various unactivated alkenes, even bulky octadecene. Additionally, the applicability of this transformation was demonstrated through a gram-scale reaction and the synthesis of a drug-active naproxen derivative.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"52 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144720287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Skylar G Norman,Lin Jiao,Jun Yi,Leo Liu,Wendu Ding,Amanda C Jones
{"title":"Solvent-Dependent Change in the Rate-Determining Step of Au(I)-Catalyzed N-Propargyl Benzamide Cyclization.","authors":"Skylar G Norman,Lin Jiao,Jun Yi,Leo Liu,Wendu Ding,Amanda C Jones","doi":"10.1021/acs.joc.5c00787","DOIUrl":"https://doi.org/10.1021/acs.joc.5c00787","url":null,"abstract":"The cyclization of N-propargyl benzamide with gold catalysts has become a popular benchmark reaction over the past two decades. The prevailing consensus denotes protodeauration as rate-limiting. Cyclization with [L1Au(NCCH3)]SbF6 and L1AuOTs (L1 = t-Bu2(o-biphenyl)P, also known as Johnphos) in dichloromethane and methanol in conjunction with deuterium labeling studies reveals a solvent-dependent switch to π-activation for the rate-limiting step. Computational calculations support this change of the rate-determining step.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"21 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144720284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Artemy R Fatkulin,Vasily A Korochantsev,Evgeniya S Podyacheva,Fedor S Kliuev,Olesya V Zvereva,Mikhail A Losev,Alexey N Rodionov,Ivan V Smirnov,Maria I Godovikova,Oleg I Afanasyev,Denis A Chusov
{"title":"Reductive Amination Reactions Using Sodium Hypophosphite: a Guide to Substrates.","authors":"Artemy R Fatkulin,Vasily A Korochantsev,Evgeniya S Podyacheva,Fedor S Kliuev,Olesya V Zvereva,Mikhail A Losev,Alexey N Rodionov,Ivan V Smirnov,Maria I Godovikova,Oleg I Afanasyev,Denis A Chusov","doi":"10.1021/acs.joc.5c00962","DOIUrl":"https://doi.org/10.1021/acs.joc.5c00962","url":null,"abstract":"The reactions of reductive amination are of paramount importance as tools of synthetic organic chemistry. Recently, the applicability of sodium hypophosphite as a promising reductant for such reactions has been demonstrated. However, the limited set of substrates used in those works does not allow for a reliable evaluation of the versatility of the approach for synthesizing amines from starting materials of different natures. Herein, we report a comprehensive study of using NaH2PO2 in the catalyst-free reductive amination. Reaction conditions suitable for various combinations of different classes of amines and carbonyl compounds have been discovered, and limitations of the process have been revealed. The study includes reaction kinetics elucidation, and the relationship between amine nucleophilicity and the outcome of this reaction has been established.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"1 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144720285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Impact of Bulky Substituents on the Singlet Arylnitrene Ring Enlargement.","authors":"Holger F Bettinger","doi":"10.1021/acs.joc.5c00720","DOIUrl":"https://doi.org/10.1021/acs.joc.5c00720","url":null,"abstract":"Substituents of the hydrindacene type allow the isolation of crystalline stable triplet arylnitrenes from photodecomposition of the corresponding aryl azides, while phenyl azide is known to produce singlet phenylnitrene that reacts to didehydroazepine via benzazirine. Comparison of computed potential energy surfaces for ring enlargement of singlet arylnitrenes suggests that bulky groups of the hydrindacene type should not significantly change the rates of formation of didehydroazepines compared to phenylnitrene. Thus, didehydroazepines could be trappable intermediates en route to stable triplet arylnitrenes.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"29 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144720288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chengcheng Ding,Xiaoyang Gao,Yimo Zhao,Kaili Feng,Yunkai Zhang,Chen Ma
{"title":"Selective Synthesis of Methyl-Substituted and Methyl-Free N-Heterocycles via Modulation of O2 Concentration.","authors":"Chengcheng Ding,Xiaoyang Gao,Yimo Zhao,Kaili Feng,Yunkai Zhang,Chen Ma","doi":"10.1021/acs.joc.5c01331","DOIUrl":"https://doi.org/10.1021/acs.joc.5c01331","url":null,"abstract":"Herein, we present a method for the selective synthesis of methyl-substituted and methyl-free N-heterocyclic compounds by adjusting the O2 concentration. This selectivity is achieved by directing the carbon synthons to act as either C1 or C2 synthons in the reaction. The process does not require any additional solvents, and ethers are compatible with this conversion. Detailed control experiments were conducted to elucidate the reason for this selective conversion, and a possible reaction mechanism is proposed. The application value of the method is demonstrated through the functionalization of the products into biologically active compounds and gram-scale experiments.","PeriodicalId":57,"journal":{"name":"Journal of Organic Chemistry","volume":"26 1","pages":""},"PeriodicalIF":4.354,"publicationDate":"2025-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144720290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}