Organic chemistry frontiers : an international journal of organic chemistry最新文献

{"title":"Synthesis and chiral self-sorting of spirobifluorene-containing boronate ester cages†‡","authors":"Natalie Schäfer ,&nbsp;Lukas Glanz ,&nbsp;Arne Lützen ,&nbsp;Florian Beuerle","doi":"10.1039/d4qo02012j","DOIUrl":"10.1039/d4qo02012j","url":null,"abstract":"<div><div>2,2′-Functionalization induces axial chirality within the orthogonal aromatic scaffold of 9,9′-bispirofluorene. By implementing boronic acids at these positions, well-suited precursors for chiral boronate ester cages are generated. As a key intermediate, (<em>P</em>)-9,9′-bispirofluorene-2,2′-bistriflate (<em>P</em>)- was synthesized <em>via</em> a four-step sequence of twofold Friedel–Crafts acylation, Baeyer–Villiger oxidation, hydrolysis, and triflate formation. Chiral resolution was achieved <em>via</em> chiral HPLC for the dihydroxy intermediate. In a modular manner, Pd-catalyzed borylation or cross-coupling afforded either diboronic acid (<em>P</em>)- or elongated derivative (<em>P</em>)- possessing additional phenylene spacers. For both enantiomerically pure linkers, reaction with hexahydroxy tribenzotriquinacene in THF under water-removing conditions afforded isoreticular chiral organic cages (<em>P</em>,<em>P</em>,<em>P</em>)- and (<em>P</em>,<em>P</em>,<em>P</em>)-. Both cages possess a chiral trigonal–bipyramidal geometry and were characterized by ¹H, ¹³C and DOSY NMR spectroscopy and MALDI-TOF mass spectrometry. Chiral self-sorting of the bispirofluorene precursors was investigated by reactions of with racemic linkers <em>rac</em>- and <em>rac</em>-. For shorter linker <em>rac</em>-, quantitative self-sorting into a racemic mixture of (<em>P</em>,<em>P</em>,<em>P</em>)- and (<em>M</em>,<em>M</em>,<em>M</em>)- occurred. For elongated derivative <em>rac</em>- however, the increased flexibility introduced by the phenylene extension resulted in much lower selectivity and self-recognition. Instead a more complex product mixture was obtained and the racemic mixture of was isolated in much lower yield of around 20%. Semiempirical PM6 calculations for both homo- and heterochiral cages and macrocyclic intermediates allowed for an estimation of macrocyclic strain energies and provided in-depth insight into cage formation pathways and self-sorting properties.</div></div>","PeriodicalId":94379,"journal":{"name":"Organic chemistry frontiers : an international journal of organic chemistry","volume":"12 6","pages":"Pages 1763-1771"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/qo/d4qo02012j?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three-step alkylaminomethylative α,β-difunctionalization of enones†","authors":"Evgeny M. Buev ,&nbsp;Vladimir S. Moshkin ,&nbsp;Vyacheslav Y. Sosnovskikh","doi":"10.1039/d4qo02259a","DOIUrl":"10.1039/d4qo02259a","url":null,"abstract":"<div><div>Aminomethylation of alkenes is a convenient methodology for the synthesis of aliphatic amines. This direction encompasses various methods, mainly allowing functionalization of the CC bond of the molecule with the aminomethyl fragment at one atom and hydrogen or a heteroatom at the other. This paper describes a three-step approach for the aminomethylation of electron-deficient alkenes, facilitating their α,β-difunctionalization and the introduction of two aminomethyl fragments into both positions of the alkene. The initial [3 + 2]-cycloaddition reaction of the nonstabilized azomethine ylide at the CC double bond of enones and subsequent treatment with alkyl halides lead to the formation of a key intermediate of the process – a quaternary ammonium salt of 3-acylpyrrolidine. Heating of such a salt in a polar solvent in the presence of a nucleophile results in a tandem Hofmann elimination/Michael addition to give 2-heteromethyl-4-aminobutan-1-ones with high diastereoselectivity and good to high overall yields. The proposed method benefits from inexpensive and available reagents, does not require noble metal catalysis and provides opportunities to apply a wide range of nucleophiles and alkyl halogenides, resulting in broad customization of the introduced heteromethyl moieties.</div></div>","PeriodicalId":94379,"journal":{"name":"Organic chemistry frontiers : an international journal of organic chemistry","volume":"12 6","pages":"Pages 1927-1935"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent advances in catalytic asymmetric reactions of Morita–Baylis–Hillman adducts","authors":"Xu-Hong Duan ,&nbsp;Hui-Rui Du ,&nbsp;Yong-Xing Song","doi":"10.1039/d4qo02212b","DOIUrl":"10.1039/d4qo02212b","url":null,"abstract":"<div><div>Morita–Baylis–Hillman adducts have become an efficient synthon for the construction of C–C or C–heteroatom bonds, and have been widely used in the asymmetric synthesis of various new optically pure compounds. The use of Morita–Baylis–Hillman acetates in asymmetric catalytic reactions has exploded since the pioneering work of Kim and co-workers. In this review, the remarkable progress of Morita–Baylis–Hillman adducts in the asymmetric construction of chiral compounds from 2012 is summarized and discussed based on the different reaction types.</div></div>","PeriodicalId":94379,"journal":{"name":"Organic chemistry frontiers : an international journal of organic chemistry","volume":"12 6","pages":"Pages 2076-2130"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dearomative 2,3-diamination of indoles triggered by Rh(iii)-catalyzed Csp2–H activation†","authors":"Chengjie Wang ,&nbsp;Huanfeng Jiang ,&nbsp;Wei Zeng","doi":"10.1039/d4qo02017k","DOIUrl":"10.1039/d4qo02017k","url":null,"abstract":"<div><div>An Rh(<span>iii</span>)-catalyzed dearomative 2,3-diamination of indoles with <em>N</em>-alkoxyamides has been developed. The method provides an efficient approach to access 2-(<em>N</em>-acylimino)-3-aminoindolines with high regioselectivity.</div></div>","PeriodicalId":94379,"journal":{"name":"Organic chemistry frontiers : an international journal of organic chemistry","volume":"12 6","pages":"Pages 1821-1826"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142936514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Supramolecular chiroptical sensing by achiral AIE-active thiols†","authors":"Xueyan Zhang ,&nbsp;Yang Li ,&nbsp;Li Wang ,&nbsp;Hongcheng Liu","doi":"10.1039/d4qo02412e","DOIUrl":"10.1039/d4qo02412e","url":null,"abstract":"<div><div>Rapid and sensitive chiroptical sensing is of great significance for practical applications. Here, a novel rapid supramolecular chiroptical sensing strategy was developed to eliminate possible background interferences and enhance the chiroptical signal by a non-chiral AIE-active thiol click reaction with chiral substrates. These AIE-thiols irreversibly bind amino acids, polypeptides, amines and amino alcohols based on a click-like reaction, and their sensing products further self-assemble, resulting in a higher chiroptical signal output. In particular, the AIE thiol generated from octyloxy-functionalized α-cyanostilbene can form supramolecular helix π–π stacking in the aggregated state, which can greatly contribute to the chiroptical sensing of the target substrate. The self-assemblies obtained from different AIE thiol sensing reactions exhibit different CD and CPL behaviors due to their different self-assembly modes, which are caused by the subtle differences in the non-covalent C–H⋯π, [π⋯π] and hydrogen bonding interactions of the chiroptical sensing reaction product. Their high reactivity and robust self-assembly sensing mechanism eliminate the interference of chiral substrates and their impurities, improving sensor sensitivity and selectivity. This strategy provides a simple and promising means of detecting chiral molecules, especially those without UV optical activity.</div></div>","PeriodicalId":94379,"journal":{"name":"Organic chemistry frontiers : an international journal of organic chemistry","volume":"12 6","pages":"Pages 1842-1849"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142937398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mastering palladium-catalyzed cross-coupling reactions: the critical role of in situ pre-catalyst reduction design†","authors":"Tommaso Fantoni ,&nbsp;Chiara Palladino ,&nbsp;Riccardo Grigolato ,&nbsp;Beatrice Muzzi ,&nbsp;Lucia Ferrazzano ,&nbsp;Alessandra Tolomelli ,&nbsp;Walter Cabri","doi":"10.1039/d4qo02335h","DOIUrl":"10.1039/d4qo02335h","url":null,"abstract":"<div><div>Palladium-catalyzed cross-coupling reactions are among the most used methods for carbon–carbon bond formation in the agrochemical and pharmaceutical segments. The key step common to all methodologies based on Pd(0) catalysis is the <em>in situ</em> generation of the active catalyst. This paper describes how to control pre-catalyst reduction in order to generate the target complex species while avoiding phosphine oxidation or, as in the case of the Heck–Cassar–Sonogashira and the Suzuki–Miyaura reactions, reactant consumption <em>via</em> dimerization. For PPh₃, DPPF, DPPP, Xantphos, SPhos, RuPhos, XPhos and sSPhos, we identified protocols that are able to maximize reduction <em>via</em> alcohols while preserving ligands and reagents. The correct combination of counterion, ligand, and base allowed the perfect control of the Pd(<span>ii</span>) reduction to Pd(0) in the presence of primary alcohols.</div></div>","PeriodicalId":94379,"journal":{"name":"Organic chemistry frontiers : an international journal of organic chemistry","volume":"12 6","pages":"Pages 1982-1991"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/qo/d4qo02335h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constructing less-conjugated olefins via unusual regioselective hydrogen atom transfer from acetals†","authors":"Zhaoshan Wang ,&nbsp;Huiying Liu ,&nbsp;Tiantian Liu ,&nbsp;Qixiang Wang ,&nbsp;Youhao Wei ,&nbsp;Xiaoguang Bao ,&nbsp;Xinxin Wu","doi":"10.1039/d4qo02099e","DOIUrl":"10.1039/d4qo02099e","url":null,"abstract":"<div><div>Utilizing a regioselective hydrogen atom transfer (RHAT) strategy, this study demonstrates a triple RHAT process accompanied by C–O bond homolysis to generate unusual less-conjugated or <em>contra</em>-thermodynamic olefins, a transformation rarely documented in the literature. The key to this conversion is the uncommon RHAT from the secondary ether C–H bond, rather than the weaker tertiary acetal C–H bond. This protocol offers a diverse class of synthetically versatile, less-conjugated, or <em>contra</em>-thermodynamic olefins.</div></div>","PeriodicalId":94379,"journal":{"name":"Organic chemistry frontiers : an international journal of organic chemistry","volume":"12 6","pages":"Pages 1911-1917"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen-inversion-based racemate aggregation and interenantiomer π-stacking-induced solid-state fluorescence enhancement†","authors":"Zesheng Huang ,&nbsp;Xiaoyi Qin ,&nbsp;Yanshan Liu ,&nbsp;Qiuhua Zhu","doi":"10.1039/d4qo02159b","DOIUrl":"10.1039/d4qo02159b","url":null,"abstract":"<div><div>The solid-state fluorescence of fluorophores is usually weakened or quenched by cofacial π-stacking. Here, the solid-state fluorescence quantum yields (<em>Φ</em>_SF) of tetrasubstituted tetrahydro-pyrimidines (TTHPs) are enhanced rather than decreased or quenched by cofacial π-stacking. All investigated TTHPs () exhibit aggregation-induced emission (AIE) characteristics: completely non-emissive in solutions owing to their soft, stereo and low-conjugated molecular structures, but become emissive upon aggregation, with <em>Φ</em>_SF equal to 3%–88%, because of the formation of an excellent through-bond/space/hyperconjugation mixed electron conjugation system, radiative-transition-favored molecular packing modes, and the restriction of molecular motion. Unexpectedly, achiral TTHPs aggregate <em>via meso</em>-enantiomers for (both N1 and N3 atoms show a pyramidal configuration) and <em>via rac</em>-enantiomers for the other TTHPs (N1 shows racemic pyramidal inversion configurations and N3 shows a planar configuration). Even more surprisingly, unlike conventional AIE fluorophores that efficiently prevent cofacial π-stacking, there is tight cofacial π-stacking between the N1-inversion-based <em>rac</em>-enantiomers, and this stacking can significantly enhance rather than decrease <em>Φ</em>_SF values by efficiently decreasing <em>k</em>_nr values, which is reported for the first time. Designing compounds with pyramidal inversion might be an efficient strategy to obtain highly emissive π-stacking aggregates.</div></div>","PeriodicalId":94379,"journal":{"name":"Organic chemistry frontiers : an international journal of organic chemistry","volume":"12 6","pages":"Pages 1803-1814"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142935437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Redox reaction between N-heterocyclic carbenes and sulfonates: insights into unproductive catalytic paths†","authors":"Jia Song ,&nbsp;Wei Wang ,&nbsp;Guanjie Wang ,&nbsp;Wen-Xin Lv","doi":"10.1039/d4qo02196g","DOIUrl":"10.1039/d4qo02196g","url":null,"abstract":"<div><div>Unproductive consumption of catalysts is a common hurdle in developing efficient catalytic reactions. In the realm of N-heterocyclic carbene (NHC) organic catalysis, attention has mainly been focused on the involvement of air (oxygen) and water in the deactivation (unproductive consumption) of the catalysts. Here, we disclose that the carbene catalyst can react with sulfonates <em>via</em> a redox process that converts NHCs into the corresponding urea molecules. This process involves rather complicated steps that ultimately transfer the oxygen atom from the sulfonate to the carbene. NHCs with different structures exhibit varying degrees of tendency in the oxidation process. Since many substrates and reagents involved in NHC catalysis possess oxidizing abilities, our study suggests that investigating potential redox processes of NHC catalysts is crucial for developing future generations of effective NHC catalysts and reactions. Our study also offers new mechanistic insights into the possible reactivities of NHCs and their adducts with other molecules.</div></div>","PeriodicalId":94379,"journal":{"name":"Organic chemistry frontiers : an international journal of organic chemistry","volume":"12 6","pages":"Pages 1879-1884"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enantioselective synthesis of vicinal diamines and β-amino amides by NiH-catalyzed hydroamidation of alkenyl amides†","authors":"Xun Tian ,&nbsp;Shengzu Duan ,&nbsp;Yuan Ma ,&nbsp;Ailin Pan ,&nbsp;Yamiao Meng ,&nbsp;Guogang Deng ,&nbsp;Hongbin Zhang ,&nbsp;Xiaodong Yang","doi":"10.1039/d4qo02275k","DOIUrl":"10.1039/d4qo02275k","url":null,"abstract":"<div><div>Enantioenriched diamines and β-amino amides are privileged scaffolds in organic and medicinal chemistry, which exhibit many applications in natural products and pharmaceutical molecules, as well as asymmetric catalysis. Catalytic asymmetric hydroamidation is considered one of the easiest ways to obtain such compounds in the enantioenriched form. Here, we report a NiH/BOX-catalyzed enantioselective hydroamidation of alkenyl amides with dioxazolones. The described transformation provides a series of enantioenriched vicinal diamines and β-amino amides, including structural modification of natural products and bioactive molecules and the preparation of the chiral radical scavenger nicaraven. A broad range of functional groups are well tolerated under room temperature with high enantioselectivities (up to 99%) and good yields (up to 87%). Mechanistic studies including the capture of a metal-nitrenoid intermediate and a competitive experiment provide significant evidence for this hydroamidation process.</div></div>","PeriodicalId":94379,"journal":{"name":"Organic chemistry frontiers : an international journal of organic chemistry","volume":"12 6","pages":"Pages 1973-1981"},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}