Pub Date : 2026-02-01DOI: 10.1021/acs.orglett.5c05387
Long Liang,Sen Yang,Xiao-Guo Zhang,Jian-Ping Wu,Zhen-Yu Wang,Lan-Jun Cheng,Xiang Wu
A DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone)-mediated oxidative [5+2] cycloaddition of isochroman-4-ones with alkynes has been described. This strategy provides an alternative method for the generation of the key benzopyrylium ylides as dipoles and affords structurally diverse benzo-fused 8-oxabicyclo[3.2.1]octanes in moderate to good yields. Mechanistic studies disclosed that the generation of benzopyrylium ylides is a radical-based process.
{"title":"DDQ-Mediated Oxidative [5+2] Cycloaddition Reactions of Isochroman-4-ones with Alkynes","authors":"Long Liang,Sen Yang,Xiao-Guo Zhang,Jian-Ping Wu,Zhen-Yu Wang,Lan-Jun Cheng,Xiang Wu","doi":"10.1021/acs.orglett.5c05387","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c05387","url":null,"abstract":"A DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone)-mediated oxidative [5+2] cycloaddition of isochroman-4-ones with alkynes has been described. This strategy provides an alternative method for the generation of the key benzopyrylium ylides as dipoles and affords structurally diverse benzo-fused 8-oxabicyclo[3.2.1]octanes in moderate to good yields. Mechanistic studies disclosed that the generation of benzopyrylium ylides is a radical-based process.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"11 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146097891","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}
Pub Date : 2026-02-01DOI: 10.1021/acs.orglett.6c00153
Laurianne Verret,Pascal Paquin,Martin Le Roy,Maxim Boucher,Éric Biron,Guillaume Bélanger-Chabot,Jean-François Morin,Jean-François Paquin
The pentafluorosulfanyl (SF5) group is a valuable fluorinated motif, but aliphatic SF5 synthesis remains challenging. We report a metal-free organophotoredox strategy to access aliphatic SF5 compounds via alkylation of vinylsulfur pentafluoride, prepared from an SF5-triflate precursor. This operationally simple transformation proceeds under mild conditions, tolerates a broad range of functional groups, and affords diverse SF5-substituted alkanes in moderate to good yields. The reaction is amenable to continuous-flow processing.
{"title":"Organophotoredox-Catalyzed Alkylation of Vinylsulfur Pentafluoride: Expanding Access to SF5-Containing Aliphatic Molecules","authors":"Laurianne Verret,Pascal Paquin,Martin Le Roy,Maxim Boucher,Éric Biron,Guillaume Bélanger-Chabot,Jean-François Morin,Jean-François Paquin","doi":"10.1021/acs.orglett.6c00153","DOIUrl":"https://doi.org/10.1021/acs.orglett.6c00153","url":null,"abstract":"The pentafluorosulfanyl (SF5) group is a valuable fluorinated motif, but aliphatic SF5 synthesis remains challenging. We report a metal-free organophotoredox strategy to access aliphatic SF5 compounds via alkylation of vinylsulfur pentafluoride, prepared from an SF5-triflate precursor. This operationally simple transformation proceeds under mild conditions, tolerates a broad range of functional groups, and affords diverse SF5-substituted alkanes in moderate to good yields. The reaction is amenable to continuous-flow processing.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"16 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146097890","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}
The enantioselective first total synthesis of (−)-citrifelin A is described herein. We found that the oxa-Pictet–Spengler reaction and acid-promoted dihydropyran formation were effective for the stereocontrolled construction of the tetracyclic framework of 1. Starting from known materials, (−)-citrifelin A was synthesized in an eight-step longest linear sequence (LLS) with an overall yield of 17%.
{"title":"Enantioselective Total Synthesis of Citrifelin A via the Oxa-Pictet–Spengler Reaction and Acid-Promoted Dihydropyran Formation","authors":"Kazuki Hori,Miyu Saito,Karen Shigeta,Shogo Kamo,Kazuyuki Sugita","doi":"10.1021/acs.orglett.5c05264","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c05264","url":null,"abstract":"The enantioselective first total synthesis of (−)-citrifelin A is described herein. We found that the oxa-Pictet–Spengler reaction and acid-promoted dihydropyran formation were effective for the stereocontrolled construction of the tetracyclic framework of 1. Starting from known materials, (−)-citrifelin A was synthesized in an eight-step longest linear sequence (LLS) with an overall yield of 17%.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"6 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098109","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}
Pub Date : 2026-02-01DOI: 10.1021/acs.orglett.6c00038
Xiaoyu Fang,Yu Jiang,Yuhan Xiao,Chenqi Wang,Ai-Jun Ma,Junyang Liu,Jia-Lei Yan
The first total synthesis of chrysosporazines B and C was accomplished in a concise and highly stereoselective manner with overall yields of 9.2% and 8.0%, respectively. Highlights of the synthesis include a Suzuki–Miyaura coupling of E-enol tosylate followed by Rh-catalyzed asymmetric hydrogenation to establish the nonsymmetric β,β-diaryl amino acid motif, a piperazinedione condensation and reduction to construct the piperazine framework, and a late-stage Pd-catalyzed carbonylation to furnish the hexahydro-6H-pyrazino[1,2-b]isoquinolin-6-one scaffold.
{"title":"Total Synthesis of Chrysosporazines B and C","authors":"Xiaoyu Fang,Yu Jiang,Yuhan Xiao,Chenqi Wang,Ai-Jun Ma,Junyang Liu,Jia-Lei Yan","doi":"10.1021/acs.orglett.6c00038","DOIUrl":"https://doi.org/10.1021/acs.orglett.6c00038","url":null,"abstract":"The first total synthesis of chrysosporazines B and C was accomplished in a concise and highly stereoselective manner with overall yields of 9.2% and 8.0%, respectively. Highlights of the synthesis include a Suzuki–Miyaura coupling of E-enol tosylate followed by Rh-catalyzed asymmetric hydrogenation to establish the nonsymmetric β,β-diaryl amino acid motif, a piperazinedione condensation and reduction to construct the piperazine framework, and a late-stage Pd-catalyzed carbonylation to furnish the hexahydro-6H-pyrazino[1,2-b]isoquinolin-6-one scaffold.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"8 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098110","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}
Herein, we present a divergent synthesis of tacaman alkaloids featuring a pivotal pentacyclic intermediate bearing an exocyclic trisubstituted olefin, accessed via a base-promoted intramolecular cyclopropanation/cyclopropane ring-opening/oxa-Michael cascade and a subsequent electrophilic halomethylation–retro-aza-Michael sequence. This versatile common intermediate enabled the regio- and diastereoselective functionalization of the trisubstituted olefin, affording the total syntheses of tacamonine, tabercamine K, and 19S-hydroxyapotacamine in good yields with excellent stereocontrol. Notably, the Mukaiyama-type hydration reaction was applied to achieve tunable stereochemistry at the C19 and C20 hydroxyl positions.
{"title":"Divergent Total Synthesis of Tacaman Alkaloids: A Skeleton Reorganization Strategy","authors":"Xiao-Feng Guo,Ya-Kui Sun,Jin-Bao Qiao,Hui Shao,Yu-Ming Zhao","doi":"10.1021/acs.orglett.6c00063","DOIUrl":"https://doi.org/10.1021/acs.orglett.6c00063","url":null,"abstract":"Herein, we present a divergent synthesis of tacaman alkaloids featuring a pivotal pentacyclic intermediate bearing an exocyclic trisubstituted olefin, accessed via a base-promoted intramolecular cyclopropanation/cyclopropane ring-opening/oxa-Michael cascade and a subsequent electrophilic halomethylation–retro-aza-Michael sequence. This versatile common intermediate enabled the regio- and diastereoselective functionalization of the trisubstituted olefin, affording the total syntheses of tacamonine, tabercamine K, and 19S-hydroxyapotacamine in good yields with excellent stereocontrol. Notably, the Mukaiyama-type hydration reaction was applied to achieve tunable stereochemistry at the C19 and C20 hydroxyl positions.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"8 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098108","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}
Pub Date : 2026-01-30DOI: 10.1021/acs.orglett.5c05211
Jin-Tao Wang,Yi-Hui Li,Hua-Feng Cao,Yuan-Qing Xu,Zhong-Yan Cao,Peng-Fei Zhang,Shengnan Jin
The hydroalkynylation of unactivated olefins presents a significant challenge, primarily due to difficulties in controlling the regioselectivity and competing reaction pathways. Herein, we report a practical NiH-catalyzed γ-selective hydroalkynylation of unactivated alkenes tethered to nitrogen heterocycles performed under external ligand-free conditions. This method provides structurally diverse alkynes in good to excellent yields with high regioselectivity and broad functional group tolerance. The synthetic utility of this approach is demonstrated through facile transformations of the products into other valuable scaffolds. Additionally, regioselectivity can be switched to the β position by employing DPPB/(TolSO3)2Ni·6H2O as a catalyst. Preliminary mechanistic studies offer insight into the reaction pathway.
{"title":"Nickel-Catalyzed Regioselective Hydroalkynylation of Nitrogen Heterocycle-Tethered Unactivated Alkenes.","authors":"Jin-Tao Wang,Yi-Hui Li,Hua-Feng Cao,Yuan-Qing Xu,Zhong-Yan Cao,Peng-Fei Zhang,Shengnan Jin","doi":"10.1021/acs.orglett.5c05211","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c05211","url":null,"abstract":"The hydroalkynylation of unactivated olefins presents a significant challenge, primarily due to difficulties in controlling the regioselectivity and competing reaction pathways. Herein, we report a practical NiH-catalyzed γ-selective hydroalkynylation of unactivated alkenes tethered to nitrogen heterocycles performed under external ligand-free conditions. This method provides structurally diverse alkynes in good to excellent yields with high regioselectivity and broad functional group tolerance. The synthetic utility of this approach is demonstrated through facile transformations of the products into other valuable scaffolds. Additionally, regioselectivity can be switched to the β position by employing DPPB/(TolSO3)2Ni·6H2O as a catalyst. Preliminary mechanistic studies offer insight into the reaction pathway.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"93 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089184","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}
Pub Date : 2026-01-30DOI: 10.1021/acs.orglett.5c05152
Srini Vemulapalli,Travis Dudding
Morden organic synthesis prizes efficiency, robustness, and generality─hallmarks of click chemistry. Here, we introduce a metal-free catalytic method for synthesizing diverse tetrazole heterocycles from simple, shelf-stable precursors. Central to this powerful strategy is leveraging cyclopropenium ions as phase-transfer catalysts, providing a practical and efficient approach to tetrazoles from nitriles and azides. The scope, mechanism, and synthetic utility of this methodology are detailed, highlighting its potential to expand the click chemistry tool box for heterocycle synthesis.
{"title":"Tetrazole Synthesis via Cyclopropenium Phase-Transfer Catalysis: A Click Strategy.","authors":"Srini Vemulapalli,Travis Dudding","doi":"10.1021/acs.orglett.5c05152","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c05152","url":null,"abstract":"Morden organic synthesis prizes efficiency, robustness, and generality─hallmarks of click chemistry. Here, we introduce a metal-free catalytic method for synthesizing diverse tetrazole heterocycles from simple, shelf-stable precursors. Central to this powerful strategy is leveraging cyclopropenium ions as phase-transfer catalysts, providing a practical and efficient approach to tetrazoles from nitriles and azides. The scope, mechanism, and synthetic utility of this methodology are detailed, highlighting its potential to expand the click chemistry tool box for heterocycle synthesis.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"4 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146073295","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}
Pub Date : 2026-01-30DOI: 10.1021/acs.orglett.6c00007
Jiang-Yu Li,Cheng-Pan Zhang
A copper-promoted synthesis of heptafluoroisopropylarenes through visible-light-induced coupling of arylsulfonium salts with AgCF(CF3)2 is presented. The reaction, conducted at room temperature under 420 nm LED irradiation, efficiently converted different types of arylsulfonium salts to the corresponding heptafluoroisopropylarenes in good yields, taming the light-sensitive silver reagent while exhibiting broad functional group tolerance and excellent chemoselectivity. This protocol was also feasible for the introduction of the CF(CF3)2 moiety into drug molecules, supplying an advantageous method for late-stage molecular functionalization.
{"title":"Photocatalytic Copper-Promoted Heptafluoroisopropylation of Arylsulfonium Salts with AgCF(CF3)2.","authors":"Jiang-Yu Li,Cheng-Pan Zhang","doi":"10.1021/acs.orglett.6c00007","DOIUrl":"https://doi.org/10.1021/acs.orglett.6c00007","url":null,"abstract":"A copper-promoted synthesis of heptafluoroisopropylarenes through visible-light-induced coupling of arylsulfonium salts with AgCF(CF3)2 is presented. The reaction, conducted at room temperature under 420 nm LED irradiation, efficiently converted different types of arylsulfonium salts to the corresponding heptafluoroisopropylarenes in good yields, taming the light-sensitive silver reagent while exhibiting broad functional group tolerance and excellent chemoselectivity. This protocol was also feasible for the introduction of the CF(CF3)2 moiety into drug molecules, supplying an advantageous method for late-stage molecular functionalization.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"4 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146073298","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}
Pub Date : 2026-01-30DOI: 10.1021/acs.orglett.6c00016
Jia-Xin Xu,Yan Zhang,Long Wang,Tao Shen,Dong-Mei Ren,Jian-Min Yue,Xiao-Ning Wang
An investigation of Trichilia connaroides uncovered connarolides A-D (1-4, respectively), four limonoids with exceptional multiring systems. Compound 1 showcased a unique 5/8/6/6-fused ring system distinguished by a bicyclo[5.2.12,4]decane A/B ring framework. Compound 2 featured a 5/8/6/5/6 scaffold incorporating a triply fused furan ring, and a long-conjugated system resulted from 3-deoxygenation. X-ray crystallography established the rare 6/3/6/6/6 ring system of 3. Moreover, 4 was identified as an antioxidant, conferring cytoprotective activity through Nrf2 activation.
{"title":"Polycyclic Limonoids as Potential Nrf2 Inducers from Trichilia connaroides.","authors":"Jia-Xin Xu,Yan Zhang,Long Wang,Tao Shen,Dong-Mei Ren,Jian-Min Yue,Xiao-Ning Wang","doi":"10.1021/acs.orglett.6c00016","DOIUrl":"https://doi.org/10.1021/acs.orglett.6c00016","url":null,"abstract":"An investigation of Trichilia connaroides uncovered connarolides A-D (1-4, respectively), four limonoids with exceptional multiring systems. Compound 1 showcased a unique 5/8/6/6-fused ring system distinguished by a bicyclo[5.2.12,4]decane A/B ring framework. Compound 2 featured a 5/8/6/5/6 scaffold incorporating a triply fused furan ring, and a long-conjugated system resulted from 3-deoxygenation. X-ray crystallography established the rare 6/3/6/6/6 ring system of 3. Moreover, 4 was identified as an antioxidant, conferring cytoprotective activity through Nrf2 activation.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"47 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089161","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}
The controlled diversification of reaction pathways from a common substrate through precise modulation of catalyst systems represents a persistent challenge in catalysis and synthetic chemistry. Herein, we report a ligand-controlled Pd-catalyzed regiodivergent (4 + 2) silacyclization between benzosilacyclobutenes and unsymmetrical phenylpropiolonitriles, which selectively affords two distinct classes of dihydrobenzo[c]silane derivatives. Each phosphine ligand steers the reaction along a unique pathway, enabling exceptional control over chemoselectivity. Through steric and electronic modulation of the ligands, both high efficiency and excellent selectivity are achieved. This strategy with divergent catalysis provides a versatile platform for the structurally diverse synthesis of silaheterocycles, with promising implications for atom-economical synthesis and functional materials.
{"title":"Palladium-Catalyzed Regiodivergent [4 + 2] Cycloaddition of Benzosilacyclobutenes with Phenylpropiolonitriles.","authors":"Xing-Ben Wang,Jun-Jie Guo,Ming-Hao Shen,Li Li,Zhuangzhi Shi,Li-Wen Xu","doi":"10.1021/acs.orglett.5c05319","DOIUrl":"https://doi.org/10.1021/acs.orglett.5c05319","url":null,"abstract":"The controlled diversification of reaction pathways from a common substrate through precise modulation of catalyst systems represents a persistent challenge in catalysis and synthetic chemistry. Herein, we report a ligand-controlled Pd-catalyzed regiodivergent (4 + 2) silacyclization between benzosilacyclobutenes and unsymmetrical phenylpropiolonitriles, which selectively affords two distinct classes of dihydrobenzo[c]silane derivatives. Each phosphine ligand steers the reaction along a unique pathway, enabling exceptional control over chemoselectivity. Through steric and electronic modulation of the ligands, both high efficiency and excellent selectivity are achieved. This strategy with divergent catalysis provides a versatile platform for the structurally diverse synthesis of silaheterocycles, with promising implications for atom-economical synthesis and functional materials.","PeriodicalId":54,"journal":{"name":"Organic Letters","volume":"281 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146073196","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}
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