Chemoselective amination is a highly desired synthetic methodology, given its importance as a possible strategy to synthesize various drug molecules and agrochemicals. We, herein, disclose a highly chemoselective Cu(II)-PTABS-promoted amination of pyrimidine structural feature containing different halogen atoms.
{"title":"Cu(II)/PTABS-Promoted, Chemoselective Amination of HaloPyrimidines.","authors":"Vikram Phulwale, Harshita Shet, Krishna Chaitanya Gunturu, Smruti Rekha Rout, Rambabu Dandela, Suyog Adhav, Anant R Kapdi","doi":"10.1021/acs.joc.4c00171","DOIUrl":"10.1021/acs.joc.4c00171","url":null,"abstract":"<p><p>Chemoselective amination is a highly desired synthetic methodology, given its importance as a possible strategy to synthesize various drug molecules and agrochemicals. We, herein, disclose a highly chemoselective Cu(II)-PTABS-promoted amination of pyrimidine structural feature containing different halogen atoms.</p>","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141326967","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}
Pub Date : 2024-07-05Epub Date: 2024-06-20DOI: 10.1021/acs.joc.4c01093
Shweta Rai, Basavarajagouda E Patil, Priti Kumari, Prathama S Mainkar, Seelam Prasanthkumar, Raju Adepu, Srivari Chandrasekhar
An aryne annulation strategy for the synthesis of fused carbazoles is developed using indolyl β-ketonitrile in a cascade manner. The reaction sequence involves aryne-mediated [2 + 2] cycloaddition cleavage and intramolecular Michael addition, followed by oxidation under transition-metal-free reaction conditions. Subsequently, conversion of benzo[b]carbazole-6-carbonitrile to carbazole quinone is observed upon prolongation of the reaction time. Furthermore, these materials exhibit high quantum efficiency, which promotes the light-emitting diode applications.
{"title":"Practical Access to Fused Carbazoles via Oxidative Benzannulation and their Photophysical Properties.","authors":"Shweta Rai, Basavarajagouda E Patil, Priti Kumari, Prathama S Mainkar, Seelam Prasanthkumar, Raju Adepu, Srivari Chandrasekhar","doi":"10.1021/acs.joc.4c01093","DOIUrl":"10.1021/acs.joc.4c01093","url":null,"abstract":"<p><p>An aryne annulation strategy for the synthesis of fused carbazoles is developed using indolyl β-ketonitrile in a cascade manner. The reaction sequence involves aryne-mediated [2 + 2] cycloaddition cleavage and intramolecular Michael addition, followed by oxidation under transition-metal-free reaction conditions. Subsequently, conversion of benzo[<i>b</i>]carbazole-6-carbonitrile to carbazole quinone is observed upon prolongation of the reaction time. Furthermore, these materials exhibit high quantum efficiency, which promotes the light-emitting diode applications.</p>","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141425710","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}
Pub Date : 2024-07-05Epub Date: 2024-06-20DOI: 10.1021/acs.joc.4c00404
Qiuling Xia, Yulong Miao, Yue Hu, Yinjun Xie, Junfei Luo
We report the first example of copper-catalyzed α-alkylation of acetamides with alcohols via a borrowing hydrogen strategy. Catalyzed by the in situ-generated copper particles, acetamides and various substituted benzyl or alkyl alcohols were transformed into functionalized amides in good yields with excellent selectivity. Compared with previous work, this process is simple using commercially available Cu(OAc)2 as a precatalyst, without an additional ligand or a metal complex, and easier. Mechanistic studies revealed that aldehyde and α,β-unsaturated amides were the intermediates of this reaction and also disclosed the role of copper in alcohol dehydrogenation and C═C bond hydrogenation.
{"title":"Copper-Catalyzed Borrowing Hydrogen Reaction for α-Alkylation of Amides with Alcohols.","authors":"Qiuling Xia, Yulong Miao, Yue Hu, Yinjun Xie, Junfei Luo","doi":"10.1021/acs.joc.4c00404","DOIUrl":"10.1021/acs.joc.4c00404","url":null,"abstract":"<p><p>We report the first example of copper-catalyzed α-alkylation of acetamides with alcohols via a borrowing hydrogen strategy. Catalyzed by the <i>in situ</i>-generated copper particles, acetamides and various substituted benzyl or alkyl alcohols were transformed into functionalized amides in good yields with excellent selectivity. Compared with previous work, this process is simple using commercially available Cu(OAc)<sub>2</sub> as a precatalyst, without an additional ligand or a metal complex, and easier. Mechanistic studies revealed that aldehyde and α,β-unsaturated amides were the intermediates of this reaction and also disclosed the role of copper in alcohol dehydrogenation and C═C bond hydrogenation.</p>","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430953","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}
The exploration of remote functionalization of indoles is impeded by the inherently dominant reactivity intrinsic to the pyrrole moiety. Herein, we delineate a novel strategy facilitated by Lewis acid mediation, enabling the remote C-H functionalization, which culminates in the synthesis of an array of selectively functionalized indole derivatives, encompassing 3-trifluoroacetyl and 5-benzoyl motifs, utilizing trifluoroacetic anhydride and various acyl chlorides. Notably, the protocol exhibits versatility, as epitomized by the extension of C5-acylation to alkylation and sulfonation reactions. This methodology is distinguished by its exemplary regio- and chemo-selectivity, extensive substrate scope, commendable tolerance to a diverse array of functional groups, and the employment of comparatively mild reaction conditions.
{"title":"Iron-Catalyzed Friedel-Crafts-type 3,5-Diacylation of Indoles.","authors":"Xiaoting Gu, Maoyi Dai, Xirui Qing, Yifeng Liu, Zhuan Zhang, Zongwu Wei, Taoyuan Liang","doi":"10.1021/acs.joc.4c01157","DOIUrl":"https://doi.org/10.1021/acs.joc.4c01157","url":null,"abstract":"<p><p>The exploration of remote functionalization of indoles is impeded by the inherently dominant reactivity intrinsic to the pyrrole moiety. Herein, we delineate a novel strategy facilitated by Lewis acid mediation, enabling the remote C-H functionalization, which culminates in the synthesis of an array of selectively functionalized indole derivatives, encompassing 3-trifluoroacetyl and 5-benzoyl motifs, utilizing trifluoroacetic anhydride and various acyl chlorides. Notably, the protocol exhibits versatility, as epitomized by the extension of C5-acylation to alkylation and sulfonation reactions. This methodology is distinguished by its exemplary regio- and chemo-selectivity, extensive substrate scope, commendable tolerance to a diverse array of functional groups, and the employment of comparatively mild reaction conditions.</p>","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141532856","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}
Pub Date : 2024-07-05DOI: 10.1021/acs.jpcb.4c02147
Xinqiang Ding
Despite force field improvements over the past decades, we still encounter situations where simulation results disagree with experiments due to force field inaccuracies. Such situations provide opportunities to improve force fields. In this study, we introduce a novel framework for optimizing force fields using experimental data. The unique feature of this framework is that it aims to optimize force fields to match experiments while minimizing the perturbation made to the original force field. To achieve this, we combine ensemble reweighting techniques with the potential contrasting method. Ensemble reweighting is used to reweight an ensemble of conformations generated using an existing force field to match experimental data while minimizing the perturbation to the original ensemble. Potential contrasting is then utilized to optimize force field parameters to reproduce the reweighted ensemble. We demonstrate the framework's effectiveness by optimizing a coarse-grained force field for intrinsically disordered proteins using experimental radius of gyration data.
{"title":"Optimizing Force Fields with Experimental Data Using Ensemble Reweighting and Potential Contrasting.","authors":"Xinqiang Ding","doi":"10.1021/acs.jpcb.4c02147","DOIUrl":"https://doi.org/10.1021/acs.jpcb.4c02147","url":null,"abstract":"<p><p>Despite force field improvements over the past decades, we still encounter situations where simulation results disagree with experiments due to force field inaccuracies. Such situations provide opportunities to improve force fields. In this study, we introduce a novel framework for optimizing force fields using experimental data. The unique feature of this framework is that it aims to optimize force fields to match experiments while minimizing the perturbation made to the original force field. To achieve this, we combine ensemble reweighting techniques with the potential contrasting method. Ensemble reweighting is used to reweight an ensemble of conformations generated using an existing force field to match experimental data while minimizing the perturbation to the original ensemble. Potential contrasting is then utilized to optimize force field parameters to reproduce the reweighted ensemble. We demonstrate the framework's effectiveness by optimizing a coarse-grained force field for intrinsically disordered proteins using experimental radius of gyration data.</p>","PeriodicalId":60,"journal":{"name":"The Journal of Physical Chemistry B","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141532835","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}
Saturated N-heterocycles are found in numerous bioactive natural products and are prevalent in pharmaceuticals and agrochemicals. While there are many methods for their synthesis, each has its limitations, such as scope and functional group tolerance. Herein, we describe a rhodium-catalyzed transfer hydrogenation of pyridinium salts to access N-(hetero)aryl piperidines. The reaction proceeds via a reductive transamination process, involving the initial formation of a dihydropyridine intermediate via reduction of the pyridinium ion with HCOOH, which is intercepted by water and then hydrolyzed. Subsequent reductive amination with an exogenous (hetero)aryl amine affords an N-(hetero)aryl piperidine. This reductive transamination method thus allows for access of N-(hetero)aryl piperidines from readily available pyridine derivatives, expanding the toolbox of dearomatization and skeletal editing.
{"title":"Reductive Transamination of Pyridinium Salts to N-Aryl Piperidines.","authors":"Zhenyu Chen, Geyang Song, Leiming Qi, Ramachandran Gunasekar, Christophe Aïssa, Craig Robertson, Alexander Steiner, Dong Xue, Jianliang Xiao","doi":"10.1021/acs.joc.4c00493","DOIUrl":"10.1021/acs.joc.4c00493","url":null,"abstract":"<p><p>Saturated N-heterocycles are found in numerous bioactive natural products and are prevalent in pharmaceuticals and agrochemicals. While there are many methods for their synthesis, each has its limitations, such as scope and functional group tolerance. Herein, we describe a rhodium-catalyzed transfer hydrogenation of pyridinium salts to access N-(hetero)aryl piperidines. The reaction proceeds via a reductive transamination process, involving the initial formation of a dihydropyridine intermediate via reduction of the pyridinium ion with HCOOH, which is intercepted by water and then hydrolyzed. Subsequent reductive amination with an exogenous (hetero)aryl amine affords an N-(hetero)aryl piperidine. This reductive transamination method thus allows for access of N-(hetero)aryl piperidines from readily available pyridine derivatives, expanding the toolbox of dearomatization and skeletal editing.</p>","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141316024","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}
Pub Date : 2024-07-05Epub Date: 2024-06-13DOI: 10.1021/acs.joc.4c00827
Chen Guo, Xinhua Wang, Qiuping Ding, Jie Wu
A three-component reaction of 1-(1H-indol-1-yl)isoquinolines or 1-(pyridin-2-yl)-1H-indoles, DABCO·(SO2)2, and thianthrenium salts under synergistic photoredox and palladium catalysis is accomplished. This direct C-H bond sulfonylation of indoles with the insertion of sulfur dioxide under mild conditions works efficiently, giving rise to a wide range of 2-sulfonated indoles in moderate to good yields under mild conditions. In this protocol, the generality of aryl/alkyl thianthrenium salts is demonstrated as well. A photoredox radical process combined with palladium catalysis is proposed.
{"title":"C-H Bond Sulfonylation from Thianthrenium Salts and DABCO·(SO<sub>2</sub>)<sub>2</sub>: Synthesis of 2-Sulfonylindoles.","authors":"Chen Guo, Xinhua Wang, Qiuping Ding, Jie Wu","doi":"10.1021/acs.joc.4c00827","DOIUrl":"10.1021/acs.joc.4c00827","url":null,"abstract":"<p><p>A three-component reaction of 1-(1<i>H</i>-indol-1-yl)isoquinolines or 1-(pyridin-2-yl)-1<i>H</i>-indoles, DABCO·(SO<sub>2</sub>)<sub>2,</sub> and thianthrenium salts under synergistic photoredox and palladium catalysis is accomplished. This direct C-H bond sulfonylation of indoles with the insertion of sulfur dioxide under mild conditions works efficiently, giving rise to a wide range of 2-sulfonated indoles in moderate to good yields under mild conditions. In this protocol, the generality of aryl/alkyl thianthrenium salts is demonstrated as well. A photoredox radical process combined with palladium catalysis is proposed.</p>","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141316021","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}
A mild protocol for electrochemically oxidative fluorodifunctionalization of styrenes has been demonstrated. The reaction proceeds under metal, external oxidant, and catalyst free conditions, allowing tunable access to a wide variety of synthetically useful fluoroalkyl derivatives, such as β-fluorosulfone/fluoromethyl, fluorothiocyanation, and vinylsulfonyl derivatives. Moreover, CsF was shown to be the proper fluorine source for this electrochemical fluorodifunctionalization transformation.
{"title":"Electrochemically Direct Fluorination Functionalization of Styrenes with Different Fluorine Source: Access to Fluoroalkyl Derivatives.","authors":"Boao Li, Xiaojian Liao, Linzi Wen, Mengyao Mi, Xiwen Xing, Pengju Feng, Shihai Xu","doi":"10.1021/acs.joc.4c00722","DOIUrl":"10.1021/acs.joc.4c00722","url":null,"abstract":"<p><p>A mild protocol for electrochemically oxidative fluorodifunctionalization of styrenes has been demonstrated. The reaction proceeds under metal, external oxidant, and catalyst free conditions, allowing tunable access to a wide variety of synthetically useful fluoroalkyl derivatives, such as β-fluorosulfone/fluoromethyl, fluorothiocyanation, and vinylsulfonyl derivatives. Moreover, CsF was shown to be the proper fluorine source for this electrochemical fluorodifunctionalization transformation.</p>","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141320144","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}
Pub Date : 2024-07-05Epub Date: 2024-06-14DOI: 10.1021/acs.joc.4c01018
Miari Kurihara, Hiroki Shigehisa
This paper reports the halocyclization of alkynoic thioesters, as S-nucleophiles, with N-halosuccinimide, followed by oxidative aromatization with the same reagent for the one-pot synthesis of thiophenes, important heterocycles exhibiting remarkable applications in different disciplines. Brief mechanistic studies were also performed to elucidate the halocyclization process. The potential diverse applications of the product, dihydrothiophene, were also assessed.
此外,还进行了简要的机理研究,以阐明卤代环化过程。此外,还评估了产品二氢噻吩的潜在多种用途。
{"title":"Halocyclization of Alkynoic Thioester and Oxidative Aromatization in One-Pot.","authors":"Miari Kurihara, Hiroki Shigehisa","doi":"10.1021/acs.joc.4c01018","DOIUrl":"10.1021/acs.joc.4c01018","url":null,"abstract":"<p><p>This paper reports the halocyclization of alkynoic thioesters, as <i>S</i>-nucleophiles, with <i>N</i>-halosuccinimide, followed by oxidative aromatization with the same reagent for the one-pot synthesis of thiophenes, important heterocycles exhibiting remarkable applications in different disciplines. Brief mechanistic studies were also performed to elucidate the halocyclization process. The potential diverse applications of the product, dihydrothiophene, were also assessed.</p>","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141320145","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}
Pub Date : 2024-07-05Epub Date: 2024-06-15DOI: 10.1021/acs.joc.4c00708
Rupali Dasharath Shinde, Anil Rajendra Paraskar, Jogendra Kumar, Eliza Ghosh, Tapan Kanti Paine, Sukalyan Bhadra
A cobalt catalyst, under oxidative conditions, facilitates the single electron transfer process in N-pyridyl arylacetamides to form α-carbon-centered radicals that readily react with molecular oxygen, giving access to mandelic acid derivatives. In contrast to the known benzylic hydroxylation approaches, this approach enables chemo- and regioselective hydroxylation at a benzylic position adjacent to (N-pyridyl)amides. Mild conditions, broad scope, excellent selectivity, and wide synthetic practicality set up the merit of the reaction.
{"title":"Cobalt Catalyzed α-Hydroxylation of Arylacetic Acid Equivalents with Dioxygen.","authors":"Rupali Dasharath Shinde, Anil Rajendra Paraskar, Jogendra Kumar, Eliza Ghosh, Tapan Kanti Paine, Sukalyan Bhadra","doi":"10.1021/acs.joc.4c00708","DOIUrl":"10.1021/acs.joc.4c00708","url":null,"abstract":"<p><p>A cobalt catalyst, under oxidative conditions, facilitates the single electron transfer process in <i>N</i>-pyridyl arylacetamides to form α-carbon-centered radicals that readily react with molecular oxygen, giving access to mandelic acid derivatives. In contrast to the known benzylic hydroxylation approaches, this approach enables chemo- and regioselective hydroxylation at a benzylic position adjacent to (<i>N</i>-pyridyl)amides. Mild conditions, broad scope, excellent selectivity, and wide synthetic practicality set up the merit of the reaction.</p>","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141326966","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}