{"title":"Chiral Magnesium(II)-Catalyzed Asymmetric Hydroalkylation of Imine-Containing Vinylazaarenes through Conjugate Addition","authors":"Dong Ye, Mingyi Jiang, Lichao Ning, Wang-Yuren Li, Lili Lin, Xiaoming Feng","doi":"10.1021/acs.orglett.5c00668","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c00668","url":null,"abstract":"The synthesis of chiral azaarenes is of great importance for pharmaceutical development. A direct and versatile approach to obtaining such compounds is the functionalization of imine-containing 2-vinylazaarenes. We have developed a chiral <i>N,N′</i>-dioxide/Mg(II) Lewis acid catalytic system to control nucleophilic <i>β</i>-cyclic or acyclic ketone amides/esters and overcome strong background reaction, enabling highly efficient enantioselective hydroalkylation of imine-containing 2-vinylazaarenes via conjugate addition. As a result, a library of chiral azaarenes bearing an all-carbon quaternary stereocenter can be obtained in high yields with good to excellent ee values. DFT calculations indicate assistances of azaarenes in hydrogen transfer, and the CH−π interaction between the substrate and the ligand’s amide group in the enantioselective differentiation.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"183 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Photoinduced Iron-Catalyzed Decarboxylation/Isomerization of gem-Difluoroallyl Carboxylic Acid to Access Vinyl Difluoromethylene Units","authors":"Shi-Yu Li, Xin-Guang Li, Wen-Qian Li, Jun Xu, Qi Zhang, Hua-Jian Xu","doi":"10.1021/acs.orglett.5c01050","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c01050","url":null,"abstract":"Vinyl difluoromethylene units (−CF−) significantly enhance the bioactivity and physical and chemical properties of compounds. Despite recent advances in introducing vinyl difluoromethylene units, radical-mediated formation of these motifs remains largely unexplored. A novel serial catalytic strategy for selective defluoroalkylation of trifluoromethyl alkenes has been developed, utilizing photocatalytic defluorocarboxylation followed by photoinduced iron-catalyzed decarboxylation/isomerization. The defluoroalkylation reaction involves generating difluoroallyl radicals, tautomerizing to vinyl difluoromethylene radicals, and proceeding through radical addition and alkylation.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"2 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Synthesis and Chiroptical Properties of a Saddle-Shaped Quadruple Helicene with a Cyclooctatetrapyrrole Core","authors":"Xu-Lang Chen, Si-Qian Yu, Zhao-Yi Cheng, Zi-You Zheng, An-Na Chen, Jinku Bai, Jia-Qi Liang, Chunyang Zheng, Xiaohuan Huang, Han-Yuan Gong","doi":"10.1021/acs.orglett.5c00294","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c00294","url":null,"abstract":"A quadruple helicene with a cyclooctatetrapyrrole core was synthesized via a simple Ullmann reaction. Its single-crystal structure exhibits a saddle shape. The compound shows fluorescence emission with λ<sub>em</sub> = 575 nm and good chiroptical properties, including a dissymmetric absorption factor (|<i>g</i><sub>abs</sub>|) of 5.84 × 10<sup>–3</sup> and a dissymmetric emission factor (|<i>g</i><sub>lum</sub>|) of 1.21 × 10<sup>–2</sup>.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"35 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Organic LettersPub Date : 2025-03-28DOI: 10.1021/acs.orglett.5c00727
Delong Mu, Xinrui Zhu, Jiean Chen
{"title":"Enantioselective Synthesis of Acenaphthene-Type Monohydrosilanes","authors":"Delong Mu, Xinrui Zhu, Jiean Chen","doi":"10.1021/acs.orglett.5c00727","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c00727","url":null,"abstract":"Acenaphthene and its analogues are privileged frameworks in medicinal chemistry and material science. However, the properties of silicon-substituted acenaphthene-type scaffolds are poorly understood. Here, we report a rhodium-catalyzed intramolecular C(sp<sup>3</sup>)–H silylation for enantioselective synthesis of acenaphthene-type scaffolds with excellent enantioselectivity and broad substrate scope. This protocol enables facile access to various quaternary stereogenic silicon centers with heterocyclic scaffolds using monohydrosilanes as chiral building blocks. We also synthesized a new silafluofen analogue that shows good insecticidal activity.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"72 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Organic LettersPub Date : 2025-03-28DOI: 10.1021/acs.orglett.5c00560
Xin-Hu Hu, Kai-Kai Zheng, Hang Yin, Ya-Hui Wang, Run-Qiao Liu, Kang-Jun Wang, Bo-Han Weng, Ming-Dong Zhou, Gui-Ping Cai, Jin Guan, Ying Yang, Jian-Fei Su, Xin-Dong Jiang, Xiang-Ping Hu
{"title":"Enantioselective Synthesis of Chiral Fluorinated Amines via Manganese-Catalyzed Asymmetric Hydrogenation","authors":"Xin-Hu Hu, Kai-Kai Zheng, Hang Yin, Ya-Hui Wang, Run-Qiao Liu, Kang-Jun Wang, Bo-Han Weng, Ming-Dong Zhou, Gui-Ping Cai, Jin Guan, Ying Yang, Jian-Fei Su, Xin-Dong Jiang, Xiang-Ping Hu","doi":"10.1021/acs.orglett.5c00560","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c00560","url":null,"abstract":"A highly enantioselective Mn-catalyzed hydrogenation of fluorinated imines has been realized. The success of this hydrogenation is attributed to the use of the chiral ferrocenyl P,N,N ligand bearing an additional chiral center at the pyridinylmethyl position. The hydrogenation displayed broad functional group tolerance, thus furnishing a wide range of optically active fluorinated amines with up to 98% enantiomeric excess. The utility of the methodology has been well-demonstrated by the scale-up of the asymmetric hydrogenation of <i>N</i>-(4′-methoxyphenyl)-ethan-2,2,2-trifluoro-1-phenyl-1-imine.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"125 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Organic LettersPub Date : 2025-03-28DOI: 10.1021/acs.orglett.5c00860
Adam R. Lockyer, Helen E. Jones, Nicholas J. Green, Robert C. Godfrey, Vera P. Demertzidou, Gary S. Nichol, Andrew L. Lawrence
{"title":"Total Synthesis of Brevianamide S","authors":"Adam R. Lockyer, Helen E. Jones, Nicholas J. Green, Robert C. Godfrey, Vera P. Demertzidou, Gary S. Nichol, Andrew L. Lawrence","doi":"10.1021/acs.orglett.5c00860","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c00860","url":null,"abstract":"The first total synthesis of the alkaloid brevianamide S has been achieved in eight steps. This natural product, isolated from <i>Aspergillus versicolor</i>, exhibits selective antibacterial activity against Bacille Calmette-Guérin (BCG), a commonly used surrogate for <i>Mycobacterium tuberculosis</i>. Brevianamide S is proposed to act through a novel, yet-to-be-elucidated mechanism, making it a promising lead in the development of next-generation antitubercular agents. Our approach employs a bidirectional synthetic strategy, involving a bespoke alkenyl–alkenyl Stille cross-coupling reaction and a double aldol condensation. This represents a flexible and efficient platform for the future synthesis of structurally diverse analogues.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"30 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fe/Mn-Synergistic Promoted C(sp3)–Bi Cross-Coupling of Alkyl Chlorides with Chlorobismuthanes to Access Air-Stable Alkylbismuthanes","authors":"Youwen Chen, Shuangshuang Li, Liyuan Le, Shuang-Feng Yin, Wei Deng, Nobuaki Kambe, Renhua Qiu","doi":"10.1021/acs.orglett.5c00623","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c00623","url":null,"abstract":"Alkylating bismuthanes containing C(sp<sup>3</sup>)–Bi bonds were first disclosed as early as 1850, but their development remains severely limited, especially the synthetic method. Herein, we developed the first Fe/Mn-synergistic promoted C(sp<sup>3</sup>)–Bi cross-coupling of alkyl halides with chlorobismuthanes, which can access alkylbismuthanes in satisfactory yields with various functional group compatibility (cyano, ester, aldehyde, and amide). Inactivated alkyl chlorides/bromides, as well as cyclic and acyclic alkyl electrophiles, smoothly yielded the corresponding products. Gram-scale synthesis and late-stage modification of drug molecules were also conducted. The synthesized alkylbismuthanes also could be alkylation reagents toward C(sp<sup>3</sup>)–C(sp<sup>2</sup>), C(sp<sup>3</sup>)–Se, C(sp<sup>3</sup>)–S, and C(sp<sup>3</sup>)–N bonds.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"30 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Organic LettersPub Date : 2025-03-28DOI: 10.1021/acs.orglett.5c00422
Alexandra E. Lubaev, Favour Eze, Manjula D. Rathnayake, Liela Bayeh-Romero
{"title":"Lewis Base-Catalyzed Interhalogenation of Terminal Allenes: Selective Strategy for Accessing Vicinal Vinylic, Allylic Heterodihalides","authors":"Alexandra E. Lubaev, Favour Eze, Manjula D. Rathnayake, Liela Bayeh-Romero","doi":"10.1021/acs.orglett.5c00422","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c00422","url":null,"abstract":"Though precedent remains limited, the selective interhalogenation of allenes offers a valuable synthetic strategy to access products where each halide exhibits orthogonal reactivity. Here, we describe a Lewis base-catalyzed approach for the dihalogenation (bromochlorination, iodochlorination, iodobromination, and dibromination) of terminal allenes. By employing just 1 mol % of triphenylphosphine oxide or hexamethylphosphoramide to activate thionyl halides in the presence of electrophilic halogenation reagents, we achieve the conversion of monosubstituted allenes to vicinal allylic, vinylic dihalides with up to 93% yield and >20:1 regioisomeric ratio, favoring the branched dihalogenated product. A range of functional groups is tolerated, including nitrile, ester, phosphate, sulfonamide, and silyl groups, and the reaction proved to be scalable. The utility of various dihalide products was investigated in substitution and cross-coupling chemistry, highlighting the distinct reactivity among the different classes.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"36 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mo-Mediated Reductive Cyclization/Allylation of 2-Alkynyl Nitroarenes with 1,3-Dienes: Synthesis of 3-Allylindoles","authors":"Jia-Yi Feng, Jian-Bang Hu, Yi Liu, Yong-Yu He, Hongguang Li, Jin-Bao Peng","doi":"10.1021/acs.orglett.5c00624","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c00624","url":null,"abstract":"3-Allylindoles constitute a key structural feature in many natural products and bioactive compounds. In this work, we developed a Mo-mediated reductive cyclization/allylation of 2-alkynyl nitroarenes with 1,3-dienes. Using Mo(CO)<sub>6</sub> as both the reductant and the catalyst, a broad range of functionalized 3-allylindoles were prepared in good to excellent yields from easily available 2-alkynylnitroarenes and 1,3-dienes as starting materials.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"42 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"[4+2] Defluorocycloaddition of Perfluoroalkyl Alkynes and Benzylamines: Synthesis of meta-Fluoroalkylated Pyridin-4-amines","authors":"Xue-Ying Huang, Jia-Wei Chen, Ding-Peng Chen, Yi-Fan Ji, Zhi-Liang Shen, Mengtao Ma, Xue-Qiang Chu","doi":"10.1021/acs.orglett.5c01004","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c01004","url":null,"abstract":"Pyridines represent privileged heterocycles, and the ability to produce fluorinated pyridines from polyfluorinated substances through selective defluorofunctionalization is a new addition to their synthesis. Herein, an unprecedented formal [4+2] defluorocycloaddition of perfluoroalkyl alkynes and benzylamines under metal-free conditions is described. By leveraging the functionalization of four C(sp<sup>3</sup>)–F bonds on two vicinal sterically hindered perfluoroalkyl carbons of perfluoroalkyl alkynes, a diverse array of <i>meta</i>-fluoroalkylated pyridin-4-amines were synthesized with good functional group tolerance. The mechanistic studies revealed a sequence of hydroamination, successive defluorination, 6π-electrocyclization, aromatization, and amination.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"37 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}