Journal of the American Chemical Society最新文献_第4页

Mixed-Valence Aryloxido-Bridged Dilanthanide Complexes with Lanthanide-Dependent Electron Delocalization. 具有镧系依赖电子离域的杂价芳氧桥接双镧系配合物。

IF 15.6 1区化学

Journal of the American Chemical Society Pub Date : 2025-10-01 DOI: 10.1021/jacs.5c05894

K Randall McClain, Hyunchul Kwon, Yasmin Whyatt, Matthew P Erodici, Andrea Mattioni, Katie R Meihaus, Benjamin G Harvey, Nicholas F Chilton, Jeffrey R Long

{"title":"Mixed-Valence Aryloxido-Bridged Dilanthanide Complexes with Lanthanide-Dependent Electron Delocalization.","authors":"K Randall McClain, Hyunchul Kwon, Yasmin Whyatt, Matthew P Erodici, Andrea Mattioni, Katie R Meihaus, Benjamin G Harvey, Nicholas F Chilton, Jeffrey R Long","doi":"10.1021/jacs.5c05894","DOIUrl":"https://doi.org/10.1021/jacs.5c05894","url":null,"abstract":"Mixed-valence lanthanide complexes of the type (CpiPr5)2Ln2I3 (CpiPr5 = pentaisopropylcyclopentadienyl; Ln = Gd, Tb, Dy, Ho, Er) featuring Ln-Ln bonding interactions can exhibit strongly coupled high-moment ground states with a large axial magnetic anisotropy. Here, we report the synthesis, structures, and magnetic properties of the aryloxido-bridged mixed-valence dilanthanide complexes (CpiPr5)2Ln2(OArtt)3 (1-Ln, Ln = Gd, Dy; -OArtt = 3,5-bis(tert-butyl)phenoxide anion). The solid-state structures of the two complexes are distinct, with 1-Dy exhibiting a nearly symmetric structure and a short Dy-Dy bond of 3.265(1) Å, suggesting valence delocalization, while 1-Gd has an asymmetric structure with each Gd atom in a distinct coordination environment, indicative of valence localization. Static magnetic susceptibility data confirm that 1-Gd is valence localized, with only very weak antiferromagnetic exchange between the GdII and GdIII centers at low temperatures. In contrast, magnetic susceptibility data for 1-Dy reveal strong magnetic coupling to give a large angular momentum ground state with magnetic blocking below 40 K. Solid-state Raman spectra for 1-Dy are indicative of Dy-Dy bonding that persists up to ambient temperatures. Computational analyses suggest that the bonding interaction in 1-Dy becomes highly polarized in the presence of slight structural asymmetry and that this effect becomes more pronounced at higher temperatures, as supported by variable-temperature single-crystal X-ray diffraction data. Detailed exploration of the vibronic coupling is consistent with vibronic-driven valence localization at elevated temperatures in 1-Dy.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":" ","pages":""},"PeriodicalIF":15.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145205096","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}

引用次数: 0

Chemoenzymatic Synthesis of Asymmetric Bisecting Bi-, Tri-, and Tetra-Antennary N-Glycans. 不对称等分双、三、四天线n -聚糖的化学酶合成。

IF 15.6 1区化学

Journal of the American Chemical Society Pub Date : 2025-10-01 DOI: 10.1021/jacs.5c11009

Balasaheb K Ghotekar, Seema K Bhagwat, Pradeep Chopra, Thomas Buckley, Geert-Jan Boons

{"title":"Chemoenzymatic Synthesis of Asymmetric Bisecting Bi-, Tri-, and Tetra-Antennary N-Glycans.","authors":"Balasaheb K Ghotekar, Seema K Bhagwat, Pradeep Chopra, Thomas Buckley, Geert-Jan Boons","doi":"10.1021/jacs.5c11009","DOIUrl":"https://doi.org/10.1021/jacs.5c11009","url":null,"abstract":"N-Acetylglucosaminyltransferase-III (GnT-III) is a glycosyltransferase that can install a β1,4-linked N-acetylglucosamine (GlcNAc) residue at the central β-mannoside of N-glycans. The resulting so-called bisecting GlcNAc is not further extended by glycosyl transferases and has been implicated in a wide range of biological processes. The molecular mechanism by which bisection modulates the biosynthesis of N-glycans and influences molecular recognition is not well understood, which is due to a lack of well-defined N-glycans with and without bisection. We describe a chemoenzymatic methodology that can readily provide a wide range of asymmetrical bisecting bi-, tri-, and tetra-antennary N-glycans. It was found GnT-III can act on bi-, tri-, and tetra-antennary N-glycans and can also accept N-glycans having a β1,2GlcNTFA or GlcN3 moiety at the α1,3- or α1,6-antenna making it possible to prepare panels of asymmetrical N-glycans with and without bisection and having different patterns of sialylation and fucosylation. Enzyme kinetic experiments showed GnT-III preferentially modifies biantennary glycans. The compounds were printed as a glycan microarray, which was screened for lectin binding. It was found that some lectins preferentially bind to bisecting glycans, whereas others do not tolerate or are not affected by this modification. We investigated receptor specificities of human H1N1 and H3N2 influenza viruses and animal H5N1 viruses that pose a pandemic threat, including a virus that has become endemic in cattle. The H1N1 and H3N2 viruses did not tolerate bisection, whereas it did not affect H5N1 viruses. A/bovine had the broadest receptor specificity, providing a rationale for its wide host range.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":" ","pages":""},"PeriodicalIF":15.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145197515","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}

引用次数: 0

Prevalent Room-Temperature Phosphorescence in Natural Nuts. 天然坚果普遍的室温磷光现象。

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2025-10-01 DOI: 10.1021/jacs.5c10814

Ruizhi Yang,Hao Su,Jiajun Song,Chendong Xie,Biao Chen,Xueyu Li,Jun Jiang,Guoqing Zhang,Yi Luo,Xuepeng Zhang,Ben Zhong Tang

{"title":"Prevalent Room-Temperature Phosphorescence in Natural Nuts.","authors":"Ruizhi Yang,Hao Su,Jiajun Song,Chendong Xie,Biao Chen,Xueyu Li,Jun Jiang,Guoqing Zhang,Yi Luo,Xuepeng Zhang,Ben Zhong Tang","doi":"10.1021/jacs.5c10814","DOIUrl":"https://doi.org/10.1021/jacs.5c10814","url":null,"abstract":"Room-temperature phosphorescence (RTP) has extensive applications in various fields such as data encryption, chemical sensing, optoelectronic displaying, and time-resolved bioimaging, yet most materials are fossil fuel-based. Recently, an increasing interest has emerged with respect to natural organic RTP. However, the cases are rare and the structure-property relationships remain poorly understood. Here, natural nuts with prevalent RTP characters were unveiled with comprehensive elucidation on the molecular origins, representing an alternative reservoir of sustainable and clean RTP materials. The nuts generally show seconds-long afterglow at ambient conditions, relying heavily on excitation wavelengths and nut composition. RTP of intrinsic nutrients including aromatic vitamins, aromatic nucleobases, and aromatic amino acids dispersed in nonaromatic natural media at low contents (as low as the ppm level) covers the entire RTP spectra of nuts, spanning <400 to >700 nm. Different aromatic nutrients require varied excitation energies and are capable of showing distinct RTP colors. Thus, biomatrices and diverse aromatic nutrients should rationalize excitation-dependent broad-band nut RTP synergistically, both of which should not be overlooked. Furthermore, nut RTP can be facilely modulated by trace polyaromatic phosphors, facilitating color-tunable 3D afterglow for multilevel information storage. This work considerably expands the scope of natural RTP based on abundant sources and provides new insights into the underlying mechanism, opening a broad avenue for applying sustainable luminescent materials that can be produced at a large scale and low cost.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"7 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145194741","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}

引用次数: 0

Ligand-Controlled Alkylation-Heck-C(sp³)-H Annulation Cascade for a Divergent Synthesis of Cyclobutane- and Cyclopropane-Containing Heterocycles. 配体控制的烷基化- heck - c (sp3)- h环结级联发散合成含环丁烷和含环丙烷杂环。

IF 15.6 1区化学

Journal of the American Chemical Society Pub Date : 2025-10-01 DOI: 10.1021/jacs.5c11047

Wan-Xu Wei, Yangjin Kuang, Martin Tomanik

{"title":"Ligand-Controlled Alkylation-Heck-C(sp3)-H Annulation Cascade for a Divergent Synthesis of Cyclobutane- and Cyclopropane-Containing Heterocycles.","authors":"Wan-Xu Wei, Yangjin Kuang, Martin Tomanik","doi":"10.1021/jacs.5c11047","DOIUrl":"https://doi.org/10.1021/jacs.5c11047","url":null,"abstract":"The ability to harness divergent reactivity and selectively dictate product outcomes from simple precursors has been a longstanding challenge in organic chemistry. Specifically, the realization of this goal in C-H functionalization remains a considerable challenge due to the inherent difficulties in achieving precise regioselective control in the presence of multiple, stereoelectronically similar C-H bonds. Herein, we report a two-component C(sp3)-H annulation cascade reaction that effectively unites ortho-bromophenols or ortho-bromoanilines with allylic alkyl bromides and provides direct access to two different heterocyclic scaffolds via precise ligand-controlled reactivity. Our newly developed transformation proceeds via an initial alkylation followed by a regioselective Heck carbopalladation and is terminated by a regiodivergent C(sp3)-H annulation of a γ-methylene or a δ-methyl C-H bond. Moreover, this C-H annulation platform provides a divergent access to spirocyclic cyclobutane or fused cyclopropane scaffolds that are frequently featured in natural products or medicinally relevant molecules. This cascade transformation possesses a broad substrate scope with respect to the aryl as well as alkyl halide components, showcased by the preparation of >60 heterocyclic products with excellent regiocontrol.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":" ","pages":""},"PeriodicalIF":15.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145205056","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}

引用次数: 0

The Singlet-Triplet Gap of Pyruvic Acid. 丙酮酸的单重态-三重态间隙。

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2025-10-01 DOI: 10.1021/jacs.5c13075

E Michi Burrow,Javier Carmona-García,Connor J Clarke,Basile F E Curchod,Jan R R Verlet

引用次数: 0

How Electrolyte pH Affects the Oxygen Reduction Reaction. 电解液pH对氧还原反应的影响。

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2025-10-01 DOI: 10.1021/jacs.5c14208

Jay T Bender,Rohan Yuri Sanspeur,Nicolas Bueno Ponce,Angel E Valles,Alyssa K Uvodich,Delia J Milliron,John R Kitchin,Joaquin Resasco

{"title":"How Electrolyte pH Affects the Oxygen Reduction Reaction.","authors":"Jay T Bender,Rohan Yuri Sanspeur,Nicolas Bueno Ponce,Angel E Valles,Alyssa K Uvodich,Delia J Milliron,John R Kitchin,Joaquin Resasco","doi":"10.1021/jacs.5c14208","DOIUrl":"https://doi.org/10.1021/jacs.5c14208","url":null,"abstract":"Electrolyte pH is known to affect catalytic activity and selectivity for the oxygen reduction reaction (ORR). But a clear understanding of why ORR rates respond more strongly to pH over certain catalysts than others has not been developed. Here, we propose that pH effects on the ORR result from electric field induced changes in the binding energies of intermediates involved in kinetically relevant elementary steps. For strongly binding metals (Pt, Ir, Ru, and Pd), whose rates are limited by the proton-coupled electron transfer (PCET) step to form *OOH or remove adsorbed OH (*OH), ORR rates are weakly affected by electrolyte pH. This behavior is observed because the binding energies of the reaction intermediates in these steps are minimally affected by electric field strength. The weak pH dependence is most pronounced for Pt, which shows essentially identical rates in acidic and alkaline electrolytes. For weakly binding metals (Au, Ag), whose rates are limited by non-PCET O2 adsorption, ORR rates increase significantly when moving from acidic to alkaline electrolytes. This strong pH dependence results from the stabilization of adsorbed O2 by the increasingly negative electric field present at the catalyst surface under alkaline conditions. We argue that modifying electrolyte pH does not change the rate-determining elementary step for the ORR, but does decrease the apparent activation barrier for O2 adsorption over weakly binding catalysts. These arguments are substantiated by a combination of experimental kinetic studies and atomistic simulations.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"16 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145194739","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}

引用次数: 0

Revealing Dynamic Structural Changes in Platinum-Group-Metal Nanoparticles during the Catalytic Hydrogen Evolution Reaction. 揭示铂族金属纳米颗粒在催化析氢反应中的动态结构变化。

IF 15.6 1区化学

Journal of the American Chemical Society Pub Date : 2025-10-01 DOI: 10.1021/jacs.5c10453

Yuto Maruta, Hirotaka Ashitani, Shogo Kawaguchi, Toshiaki Ina, Osami Sakata, Yoshiki Kubota, Tomokazu Yamamoto, Takaaki Toriyama, Yasukazu Murakami, Megumi Mukoyoshi, Hiroshi Kitagawa, Kohei Kusada

{"title":"Revealing Dynamic Structural Changes in Platinum-Group-Metal Nanoparticles during the Catalytic Hydrogen Evolution Reaction.","authors":"Yuto Maruta, Hirotaka Ashitani, Shogo Kawaguchi, Toshiaki Ina, Osami Sakata, Yoshiki Kubota, Tomokazu Yamamoto, Takaaki Toriyama, Yasukazu Murakami, Megumi Mukoyoshi, Hiroshi Kitagawa, Kohei Kusada","doi":"10.1021/jacs.5c10453","DOIUrl":"https://doi.org/10.1021/jacs.5c10453","url":null,"abstract":"Despite the crucial role of structural dynamics in catalytic reactions, the influence of nanoparticle (NP) size and elemental composition on these dynamics under electrochemical conditions is often overlooked. Herein, we present the first systematic operando investigation of the size- and element-dependent structural and electronic dynamics of platinum-group-metal (PGM) NPs (Pt, Pd, Rh, and Ru) during the hydrogen evolution reaction (HER) under both acidic and alkaline conditions. By combining operando powder X-ray diffraction and X-ray absorption spectroscopy, we revealed that the smaller the NPs, the more significant the structural changes, indicating surface adsorbate-induced dynamics. Notably, we also found that the constant lattice expansion in Pt, Pd, and Rh NPs occurred on a slow time scale (several tens of seconds). The electronic states of these NPs were more reductive than their standard zerovalent states owing to interactions with hydrogen. However, the Ru NPs remained oxidized even during the HER, indicating distinct electronic changes in the PGMs. These findings reveal previously unrecognized dynamics, providing a comprehensive understanding of how size and composition influence the structural and electronic changes of PGM NPs in realistic electrochemical reaction environments. This study establishes a foundational framework for operando catalyst investigations and opens new avenues for the rational design of size- and element-optimized HER catalysts.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":" ","pages":""},"PeriodicalIF":15.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145205024","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}

引用次数: 0

An Enantioselective Nucleophilic Aromatic tele-Substitution. 对映选择性亲核芳烃远端取代。

IF 15.6 1区化学

Journal of the American Chemical Society Pub Date : 2025-10-01 DOI: 10.1021/jacs.5c14328

Valdemar J Enemærke, Anne Kristensen, Louise G Rost, Esben Skovsgaard, Karl Anker Jørgensen

{"title":"An Enantioselective Nucleophilic Aromatic tele-Substitution.","authors":"Valdemar J Enemærke, Anne Kristensen, Louise G Rost, Esben Skovsgaard, Karl Anker Jørgensen","doi":"10.1021/jacs.5c14328","DOIUrl":"https://doi.org/10.1021/jacs.5c14328","url":null,"abstract":"This work presents the first leaving-group-directed aminocatalytic enantioselective nucleophilic aromatic tele-substitution on the tropone scaffold. The integration of an appropriate leaving group on tropone enables the nucleophilic aromatic substitution with carbon nucleophiles under mild reaction conditions, a reaction which has previously only been reported under harsh reaction conditions. An efficient and highly enantioselective approach for the remote installation of quaternary all-carbon stereocenters via tele-substitution is reported. Mild reaction conditions are achieved by employing a primary amine catalyst with α-branched aldehydes affording enantioenriched tropones in up to 96% yield and up to 97% ee. The tele-substitution pathway is elucidated by a series of both qualitative and quantitative deuterium-labeling studies and different substitution patterns on the tropone scaffold. DFT calculations reveal that the geometry of the enamine governs the stereochemical outcome. H-Bonding, π-π interaction, and a cation-π interaction were found to be crucial in the stereodetermining step.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":" ","pages":""},"PeriodicalIF":15.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145197559","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}

引用次数: 0

β-Fluorovinylsulfonamide as a Highly Reactivity- and Structure-Tunable Electrophile for Covalent Targeting of Proteins. β-氟乙烯基磺酰胺作为共价靶向蛋白的高反应性和结构可调亲电试剂。

IF 15.6 1区化学

Journal of the American Chemical Society Pub Date : 2025-10-01 DOI: 10.1021/jacs.5c07422

Shunsuke Watanabe, Keisuke Tokunaga, Yudai Tanaka, Yuya Hirose, Emi Mishiro-Sato, Keiko Kano, Kaori Sasaki-Tabata, Yuri Kato, Motohiro Nishida, Naoya Shindo, Akio Ojida

{"title":"β-Fluorovinylsulfonamide as a Highly Reactivity- and Structure-Tunable Electrophile for Covalent Targeting of Proteins.","authors":"Shunsuke Watanabe, Keisuke Tokunaga, Yudai Tanaka, Yuya Hirose, Emi Mishiro-Sato, Keiko Kano, Kaori Sasaki-Tabata, Yuri Kato, Motohiro Nishida, Naoya Shindo, Akio Ojida","doi":"10.1021/jacs.5c07422","DOIUrl":"https://doi.org/10.1021/jacs.5c07422","url":null,"abstract":"Covalent targeting of proteins with small molecule probes is a powerful approach for analyzing and manipulating biological functions. Recent advancements in the design of target selective covalent ligands further expand the scope of accessible proteins in this approach. Here we report β-fluorovinylsulfonamide (FVS) as a versatile electrophile for the design of covalent ligands. FVS irreversibly reacts with cysteine residues in proteins to afford stable vinyl sulfide adducts. The reactivity of FVS is maintained with the introduction of various substituents at the β-position, allowing for fine-tuning of the electrophilic reactivity and flexible molecular design of FVS-based covalent ligands. These reaction properties were leveraged in the development of highly selective covalent ligands for RSK2 and BTK. FVS compounds are also able to react with lysine residues in proteins to form enamine-type reversible covalent adducts, which are susceptible to hydrolysis under neutral aqueous conditions. This lysine reactivity of FVS led to the discovery of FVS compound 53 as a reversible covalent ligand for PFKL, which selectively reacts with K677 of PFKL and allosterically upregulates PFKL activity in living cells.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":" ","pages":""},"PeriodicalIF":15.6,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145205123","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}

引用次数: 0

Total Syntheses of Giraldine I and Heterophyllisine. 吉拉尔丁I和杂茶碱的全合成。

IF 15 1区化学

Journal of the American Chemical Society Pub Date : 2025-10-01 DOI: 10.1021/jacs.5c14513

Chuang Li,Fei Lu,Ningwei Wang,Cheng Zhang,Guanrui He,Wenli Lei,Jing Liu,Jiamin Wang,Xiao-Yu Liu,Yong Qin

引用次数: 0