Journal of the American Chemical Society最新文献

{"title":"Migratory Aryl Cross-Coupling","authors":"Yoshiya Sekiguchi, Polpum Onnuch, Yuli Li, Richard Y. Liu","doi":"10.1021/jacs.4c15086","DOIUrl":"https://doi.org/10.1021/jacs.4c15086","url":null,"abstract":"A fundamental property of cross-coupling reactions is regiospecificity, meaning that the site of bond formation is determined by the leaving group’s location on the electrophile. Typically, achieving a different substitution pattern requires the synthesis of a new, corresponding starting-material isomer. As an alternative, we proposed the development of cross-coupling variants that would afford access to multiple structural isomers from the same coupling partners. Here, we first demonstrate that a bulky palladium catalyst can facilitate the efficient, reversible transposition of aryl halides by temporarily forming metal aryne species. Despite the nearly thermoneutral equilibrium governing this process, combining it with the gradual addition of a suitable nucleophile results in dynamic kinetic resolution of the isomeric intermediates and high yields of unconventional product isomers. The method accommodates a range of oxygen- and nitrogen-centered nucleophiles and tolerates numerous common functional groups. A Curtin–Hammett kinetic scheme is supported by computational and experimental data, providing a general mechanistic framework for extending this migratory cross-coupling concept.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"12 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841606","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":"Mechanism of C-3 Acyl Neighboring Group Participation in Mannuronic Acid Glycosyl Donors","authors":"Frank F. J. de Kleijne, Peter H. Moons, Floor ter Braak, Hero R. Almizori, Luuk J. H. Jakobs, Kas J. Houthuijs, Giel Berden, Jonathan Martens, Jos Oomens, Floris P. J. T. Rutjes, Paul B. White, Thomas J. Boltje","doi":"10.1021/jacs.4c13910","DOIUrl":"https://doi.org/10.1021/jacs.4c13910","url":null,"abstract":"One of the main challenges in oligosaccharide synthesis is the stereoselective introduction of the glycosidic bond. In order to understand and control glycosylation reactions, thorough mechanistic studies are required. Reaction intermediates found by NMR spectroscopy often cannot explain the glycosylation’s stereochemical outcome. Hence, reactions may proceed through low-abundance reaction intermediates that are difficult to detect, according to a Curtin–Hammett scenario. We have previously observed that manno-type sugars can engage in C-3 acyl neighboring group participation. Herein, we report the detection of glycosyl dioxanium ions that result from C-3 neighboring group participation in mannuronic acid donors. Using a suite of exchange NMR techniques, we were able to dissect the kinetics of the conformational ring-flip that precedes C-3 acyl participation and the participation event itself in various manno-type sugars. Hence, this study provides a complete picture of mannosyl dioxanium ion formation.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841602","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":"Mechanism-Inspired Synthesis of Poly(alkyl malonates) via Alternating Copolymerization of Epoxides and Meldrum’s Acid Derivatives","authors":"Sarah M. Severson, Bai-Hao Ren, May Cayzer, Ivan Keresztes, Mary L. Johnson, Xiao-Bing Lu, Geoffrey W. Coates","doi":"10.1021/jacs.4c13550","DOIUrl":"https://doi.org/10.1021/jacs.4c13550","url":null,"abstract":"Direct incorporation of malonate units into polymer backbones is a synthetic challenge. Herein, we report the alternating and controlled anionic copolymerization of epoxides and Meldrum’s acid (MA) derivatives to access poly(alkyl malonates) using (<i>N,N’</i>-bis(salicylidene)phenylenediamine)AlCl and a tris(dialkylamino)cyclopropenium chloride cocatalyst. This unique copolymerization yields a malonate-containing repeat unit while releasing a small molecule upon MA-derivative ring-opening. Mechanistic and computational studies reveal that the nature of the small molecule released influences overall polymerization kinetics, side reaction behavior, and molecular weight control. Controlled copolymerization of MA derivatives with a range of epoxides ultimately yields a library of new poly(alkyl malonates) with diverse and tunable thermal properties.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"68 783-784 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142849533","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":"Pd-Catalyzed Migratory 1,1-Cycloannulation Reaction of Alkenes","authors":"Jin-Ping Wang, Tao Liu, Yichen Wu, Peng Wang","doi":"10.1021/jacs.4c14153","DOIUrl":"https://doi.org/10.1021/jacs.4c14153","url":null,"abstract":"Here, we report a novel strategy for the preparation of diverse heterocycles via a Pd-catalyzed migratory 1,1-cycloannulation reaction (MCAR) of alkenes. Starting from readily available alkenyl amines and alkenyl alcohols, this approach allows the formation of a wide range of five- to seven-membered azaheterocycles and oxaheterocycles with high efficiency and good functional group tolerance. The key to the realization of this reaction is the use of 4-iodophenol or 2-iodophenol derivatives where the phenolic hydroxyl group plays a critical role in controlling the direction of migration and the ring-size of the heterocycles through the formation of a quinone methide intermediate.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"11 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841604","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":"Effect of Strain on the Photocatalytic Reaction of Graphitic Carbon Nitride: Insight from Single-Molecule Localization Microscopy","authors":"Jia Xin Chan, Shuyang Wu, Jinn-Kye Lee, Mingyu Ma, Zhengyang Zhang","doi":"10.1021/jacs.4c13707","DOIUrl":"https://doi.org/10.1021/jacs.4c13707","url":null,"abstract":"Strain engineering in two-dimensional nanomaterials holds significant potential for modulating the lattice and band structure, particularly through localized strain, which enables modulation at specific regions. Despite the remarkable effects of local strain, the relationships among local strain, spatial correlation of photogenerated charge carriers, and photocatalytic performance remain elusive. The current study coupled single-molecule localization microscopy with coordinate-based colocalization (CBC) analysis to explain these relationships. The methodology involved mapping the spatial distributions of photoinduced oxidation and reduction reaction sites across graphitic carbon nitride (g-C₃N₄) nanosheets, quantifying and spatially resolving their spatial correlation, and also evaluating their photocatalytic activity. The study examined 65 individual g-C₃N₄ nanosheets, revealing interparticle and intraparticle heterogeneity, which was classified based on their CBC score distributions. Among the 65 g-C₃N₄ nanosheets, type A nanosheets predominated (45 out of 65) and demonstrated both correlated and noncorrelated subregions along some wrinkles. In contrast, type B nanosheets (20 out of 65) were primarily characterized by noncorrelated subregions with minimal correlated localizations. The coexistence of both noncorrelated and correlated subregions inferred the structure of the wrinkles as folding wrinkles, which have larger tensile-strained areas than rippling wrinkles. Folding wrinkles promote colocalization through the formation of type I band alignment at tensile-strained subregions. This band alignment also enhances photocatalytic activity through a funneling effect and improved light absorption, leading to higher specific activity in correlated subregions compared to noncorrelated ones. The role of strain-induced band alignment in modulating the spatial correlation of the photoredox reaction and the photocatalytic performance at the subregion level is highlighted.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"52 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841601","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":"Constructing Atomic Tungsten-Based Solid Frustrated-Lewis-Pair Sites with d-p Interactions for Selective CO2 Photoreduction","authors":"Baorong Xu, Shicheng Luo, Weibo Hua, Hang Xiao, Ben Chong, Guocheng Yan, He Li, Honghui Ou, Bo Lin, Guidong Yang","doi":"10.1021/jacs.4c08953","DOIUrl":"https://doi.org/10.1021/jacs.4c08953","url":null,"abstract":"Solid frustrated Lewis pair (FLP) shows remarkable advantages in the activation of small molecules such as CO₂, owing to the strong orbital interactions between FLP sites and reactant molecules. However, most of the currently constructed FLP sites are randomly distributed and easily reunited on the surface of catalysts, resulting in a low utilization rate of FLP sites. Herein, atomic tungsten-based FLP (N···W_SA FLP) sites are constructed for photocatalytic CO₂ conversion through introducing W single-atoms into polymeric carbon nitride. In the atomically dispersed N···W_SA FLP, the electron-deficient W single-atom acts as the Lewis acid (LA), and the adjacent electron-rich N atom acts as the Lewis base. Through the combination of various characterizations, including pyridine-IR, in situ diffuse reflectance infrared Fourier transform spectroscopy, CO₂-temperature programmed desorption, and theoretical calculations, the positive effects of N···W_SA FLP on photocatalytic CO₂ reduction are well revealed. The N···W_SA FLP can effectively adsorb CO₂ to form an unusual W–O–C–N structure with significant d-p orbital interactions, which leads to an interesting “push–push” electron transfer effect. The π back-donation from W 5d to the antibonding orbital (2π) of CO₂ realizes reverse electron transfer from the W single-atom to the O site, while the electrons are transferred from the electron-rich N site to the electropositive C site via Lewis acid–base interactions, therefore effectively breaking the C═O bond to activate CO₂ molecules and boost CO₂-to-CO performance. This work provides a brand new route for the research on high-efficiency activation of small molecules based on single-atom-based FLP catalysts.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"12 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841550","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":"CF3-Functionalized Side Chains in Nonfullerene Acceptors Promote Electrostatic Interactions for Highly Efficient Organic Solar Cells","authors":"Yongjoon Cho, Zhe Sun, Guoping Li, Dayong Zhang, Sangjin Yang, Tobin J. Marks, Changduk Yang, Antonio Facchetti","doi":"10.1021/jacs.4c13471","DOIUrl":"https://doi.org/10.1021/jacs.4c13471","url":null,"abstract":"The advent of next-generation nonfullerene acceptors (NFAs) has propelled major advances in organic solar cells (OSCs). Here we report an NFA design incorporating CF₃-terminated side chains having varying <i>N</i>-(CH₂)_n-CF₃ linker lengths (<i>n</i> = 1, 2, and 3) which introduce new intermolecular interactions, hence strong modulation of the photovoltaic response. We report a systematic comparison and contrast characterization of this NFA series with a comprehensive set of chemical/physical techniques versus the heavily studied third-generation NFA, Y6, revealing distinctive and beneficial properties of this new NFA series. Single-crystal diffraction analyses reveal unusual two-dimensional mesh-like crystal structures, featuring strong interactions between the side chain CF₃-terminal and NFA core F substituents. These atomistic and morphological features contribute to enhanced charge mobility and significantly enhanced photovoltaic performance. We show that varying the CF₃-terminated side chain linker length strongly modulates light harvesting efficiency as well as charge recombination and the photovoltaic bandgap. The CF₃-(CH₂)₂-based OSC demonstrates the most balanced performance metrics, achieving a remarkable 19.08% power conversion efficiency and an exceptional 80.09% fill-factor. These results imply that introducing CF₃-terminated side chains into other OSC conjugated constituents may accelerate next-generation solar cell development.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"27 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841599","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":"Photochemical Deracemization of Lactams with Deuteration Enabled by Dual Hydrogen Atom Transfer","authors":"Xiaoyu Yan, Yubing Pang, Yutong Zhou, Rui Chang, Juntao Ye","doi":"10.1021/jacs.4c14934","DOIUrl":"https://doi.org/10.1021/jacs.4c14934","url":null,"abstract":"Photochemical deracemization has emerged as one of the most straightforward approaches to access highly enantioenriched compounds in recent years. While excited-state events such as energy transfer, single electron transfer, and ligand-to-metal charge transfer have been leveraged to promote stereoablation, approaches relying on hydrogen atom transfer, which circumvent the limitations imposed by the triplet energy and redox potential of racemic substrates, remain underexplored. Conceptually, the most attractive method for tertiary stereocenter deracemization might be hydrogen atom abstraction followed by hydrogen atom donation. However, implementing such a strategy poses significant challenges, primarily because the enantioenriched products are also reactive if the chiral catalyst is unable to differentiate between the two enantiomers. Herein we report a distinct dual hydrogen atom transfer strategy for photochemical deracemization of δ- and γ-lactams, achieving high enantioenrichment and deuterium incorporation despite the inherent reactivity of the products. Mechanistic studies reveal that benzophenone enables nonselective hydrogen atom abstraction while a tetrapeptide-derived thiol dictates the enantioselectivity of the hydrogen atom donation step. More importantly, a pyridine-based alcohol was found to play crucial roles in facilitating the hydrogen atom abstraction as well as enhancing the enantioselectivity of the hydrogen atom donation step.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"17 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841603","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":"Biomimetic Synthesis of Azorellolide via Cyclopropylcarbinyl Cation Chemistry","authors":"Jordan Y. Artzy, Dean J. Tantillo, Dirk H. Trauner","doi":"10.1021/jacs.4c14664","DOIUrl":"https://doi.org/10.1021/jacs.4c14664","url":null,"abstract":"A concise synthesis of the complex diterpene azorellolide, inspired by speculations on biosynthetic cationic cascades, is presented. The approach, guided by computation, relies on the intramolecular interception of a cyclopropylcarbinyl cation by an appended carboxylate. The successful execution of this strategy was achieved through acid-catalyzed isomerization of a β-lactone in competition with a type I dyotropic rearrangement.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"23 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841600","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":"Catalytic Asymmetric Oxidative Coupling between C(sp3)–H Bonds and Carboxylic Acids","authors":"Xian-Ming Liu, Fu Li, Tongkun Wang, Ling Dai, Yin Yang, Neng-Quan Jiang, Li-Yuan Xue, Jing-Yuan Liu, Xiao-Song Xue, Li-Jun Xiao, Qi-Lin Zhou","doi":"10.1021/jacs.4c12544","DOIUrl":"https://doi.org/10.1021/jacs.4c12544","url":null,"abstract":"The direct enantioselective functionalization of C(sp³)–H bonds in organic molecules could fundamentally transform the synthesis of chiral molecules. In particular, the enantioselective oxidation of these bonds would dramatically change the production methods of chiral alcohols and esters, which are prevalent in natural products, pharmaceuticals, and fine chemicals. Remarkable advances have been made in the enantioselective construction of carbon–carbon and carbon–nitrogen bonds through the C(sp³)–H bond functionalization. However, the direct enantioselective formation of carbon–oxygen bonds from C(sp³)–H bonds remains a considerable challenge. We herein report a highly enantioselective C(sp³)–H bond oxidative coupling with carboxylic acids. The method applies to allylic and propargylic C–H bonds and employs various carboxylic acids as oxygenating agents. The method successfully synthesized a range of chiral esters directly from readily available alkenes and alkynes, greatly simplifying the synthesis of chiral esters and related alcohols.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"28 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841609","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}