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Palladium-Catalyzed [3+2+2] Cycloaddition Between Carbonyl-Tethered Alkylidenecyclopropanes and Isocyanates 钯催化羰基系链烷基环丙烷与异氰酸酯之间的[3+2+2]环加成反应
IF 1.5 4区 化学
Helvetica Chimica Acta Pub Date : 2025-02-20 DOI: 10.1002/hlca.202500011
Ricardo Rodiño, Jose L. Mascareñas, Fernando López
{"title":"Palladium-Catalyzed [3+2+2] Cycloaddition Between Carbonyl-Tethered Alkylidenecyclopropanes and Isocyanates","authors":"Ricardo Rodiño,&nbsp;Jose L. Mascareñas,&nbsp;Fernando López","doi":"10.1002/hlca.202500011","DOIUrl":"https://doi.org/10.1002/hlca.202500011","url":null,"abstract":"<p>Carbonyl-tethered alkylidenecyclopropanes can react with aryl isocyanates in presence of Pd(0)-phosphoramidite catalysts to give seven-membered heterobicyclic products in a formal [3+2+2] cycloaddition process. The reaction involves the formation of a palladium π-allyl complex intermediate (<b>A</b>), which behaves as a formal 1,5-dipole, and can be trapped by externally added isocyanates. This report also includes preliminary assays of asymmetric variants, as well as DFT computational studies that shed some light on the nature of the catalytic cycle.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Access to Enantioenriched 1,n-Diols by Cu-Catalyzed Enantioselective Protoboration and Hydroboration of Alkenyl Ethers 铜催化烯基醚的对映选择性原硼化和硼化反应制备富集对映体的1，n-二醇
IF 1.5 4区 化学
Helvetica Chimica Acta Pub Date : 2025-02-18 DOI: 10.1002/hlca.202500009
Arthur Flaget, Orlando Cesa, Clément Mazet
{"title":"Access to Enantioenriched 1,n-Diols by Cu-Catalyzed Enantioselective Protoboration and Hydroboration of Alkenyl Ethers","authors":"Arthur Flaget,&nbsp;Orlando Cesa,&nbsp;Clément Mazet","doi":"10.1002/hlca.202500009","DOIUrl":"https://doi.org/10.1002/hlca.202500009","url":null,"abstract":"<p>We report two catalytic enantioselective borylation/oxidation sequences that streamline access to either enantioenriched 1,2- or 1,3-diols starting from <i>O</i>-benzyl-protected allylic alcohols as a single precursor. The approach takes advantage of the complementary regioselectivity of the Cu-catalyzed protoboration and the Cu-catalyzed hydroboration of disubstituted alkenes, which effectively install a borane function and a hydrogen atom on opposite C(sp<sup>2</sup>) carbon atoms of a carbon–carbon double bond. The two methods feature broad substrate scope and are amenable to large scale without measurable loss of the catalytic efficiency. Both protocols display high levels of regioselectivity and enantioselectivity.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Cover Picture: (Helv. Chim. Acta 2/2025) 封面图片：（Helv.）詹。Acta 2/2025)
IF 1.5 4区 化学
Helvetica Chimica Acta Pub Date : 2025-02-14 DOI: 10.1002/hlca.202570201
{"title":"Cover Picture: (Helv. Chim. Acta 2/2025)","authors":"","doi":"10.1002/hlca.202570201","DOIUrl":"https://doi.org/10.1002/hlca.202570201","url":null,"abstract":"<p>\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure>\u0000 </p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202570201","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Recent Progress in Visible Light-Mediated Synthesis of γ-lactams 可见光介导合成γ-内酰胺的研究进展
IF 1.5 4区 化学
Helvetica Chimica Acta Pub Date : 2025-01-30 DOI: 10.1002/hlca.202400206
Suman Pradhan, Shoubhik Das
{"title":"Recent Progress in Visible Light-Mediated Synthesis of γ-lactams","authors":"Suman Pradhan,&nbsp;Shoubhik Das","doi":"10.1002/hlca.202400206","DOIUrl":"https://doi.org/10.1002/hlca.202400206","url":null,"abstract":"<p>The integration of sustainable practices, such as employing renewable light sources for synthesizing valuable synthetic scaffolds, has been progressing over the past few decades. Among these noteworthy organic frameworks, lactams, particularly γ-lactams, have established their prominence due to their extensive applications in the pharmaceutical, agricultural, and medicinal domains. This growing significance of γ-lactams has spurred considerable interest in their synthesis, especially via milder, more sustainable, and environmentally friendly methods. In recent years, numerous innovative reaction mechanisms have been explored, highlighting how photocatalysis can enable the formation of γ-lactams from readily accessible precursors through C−N bond formation and cyclization processes. This review emphasizes the potential of photocatalytic strategies to not only enhance current synthetic methods for γ-lactams but also foster the development of greener and more sustainable chemical processes for the future.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143840948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Introduction for the Special Collection in the Honor of Scott Denmark 为纪念史考特·丹麦而特别收藏的介绍
IF 1.5 4区 化学
Helvetica Chimica Acta Pub Date : 2025-01-30 DOI: 10.1002/hlca.202400183
Jeffrey Bode, Cathleen Crudden
{"title":"Introduction for the Special Collection in the Honor of Scott Denmark","authors":"Jeffrey Bode,&nbsp;Cathleen Crudden","doi":"10.1002/hlca.202400183","DOIUrl":"https://doi.org/10.1002/hlca.202400183","url":null,"abstract":"<p>\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure>\u0000 </p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400183","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Synthesis of α-Fluoroketones from Carboxylic Acids via Decarboxylation of Fluorinated Malonates 氟化丙二酸酯脱羧法由羧酸合成α-氟酮
IF 1.5 4区 化学
Helvetica Chimica Acta Pub Date : 2025-01-29 DOI: 10.1002/hlca.202400187
Raffael Davenport, Rolandas Cibiras, Gabriel Schäfer
{"title":"Synthesis of α-Fluoroketones from Carboxylic Acids via Decarboxylation of Fluorinated Malonates","authors":"Raffael Davenport,&nbsp;Rolandas Cibiras,&nbsp;Gabriel Schäfer","doi":"10.1002/hlca.202400187","DOIUrl":"https://doi.org/10.1002/hlca.202400187","url":null,"abstract":"<p>α-Fluoroketones are versatile intermediates for the synthesis of fluorinated heterocycles and other fluorine-containing building blocks. We have recently disclosed a novel route to such an α-fluoroketone using the corresponding benzoic acid as a starting material. The reaction sequence started with the CDI-activation of the carboxylic acid and reaction with diethyl malonate, fluorination of the resulting acyl malonate with Selectfluor, and finally a double-decarboxylation to provide the desired α-fluoroketone in 73 % yield over three telescoped steps. We were interested in the generality of this approach to access α-fluoroketones from readily available carboxylic acids. In this article, we disclose the crucial modifications of the reaction conditions that were needed to make them broadly applicable to a diverse array of carboxylic acids. Under the optimized conditions, a wide range of α-fluoroketones were isolated in good to excellent yields and in high purity.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Effect of Particle Size and Alloying with Gallium and Zinc in Copper Nanoparticles from Ab Initio Molecular Dynamics 从从头算分子动力学看铜纳米颗粒尺寸及镓锌合金化的影响
IF 1.5 4区 化学
Helvetica Chimica Acta Pub Date : 2025-01-24 DOI: 10.1002/hlca.202400124
Andreas Müller, Aleix Comas-Vives, Christophe Copéret
{"title":"Effect of Particle Size and Alloying with Gallium and Zinc in Copper Nanoparticles from Ab Initio Molecular Dynamics","authors":"Andreas Müller,&nbsp;Aleix Comas-Vives,&nbsp;Christophe Copéret","doi":"10.1002/hlca.202400124","DOIUrl":"https://doi.org/10.1002/hlca.202400124","url":null,"abstract":"<p>Supported nanoparticles (NPs) are an intense field of research in industry and academia due to their unique catalytic properties. Yet, establishing relationships between structure and activity is challenging due to multiple possible compositions, interfaces, and alloy formation. This is especially pronounced for bimetallic NPs used in the CO<sub>2</sub>-hydrogenation-to-methanol, where the structure responds dynamically to the chemical potential of the reactants and products, resulting in distinct surface structures depending on the exact reaction conditions. These phenomena have been highlighted by combining <i>ab initio</i> Molecular Dynamics (AIMD) and Metadynamics (MTD) with <i>in situ</i> X-ray absorption spectroscopy, chemisorption, and CO-IR. Here, we aim to understand how particle size and simulation temperature influence the structure and dynamics of small Cu NPs using the diffusion coefficients and the radial distribution function/atomic pair density function as descriptors using AIMD simulations. We found that decreasing the particle size or increasing the simulation temperature results in increased atom mobility, highlighted by the increased metal diffusion and resulting in reduced particle crystallinity. We also find that alloying Cu with Ga significantly increases the diffusion of both elements in the particle compared to the monometallic ones. In contrast, such diffusion lies in between the individual elements composing the CuZn particles.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400124","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Structure and Magnetic Properties of a Series of Uranium Bis-Siloxide Complexes 一系列铀铋-硅氧化物配合物的结构和磁性能
IF 1.5 4区 化学
Helvetica Chimica Acta Pub Date : 2025-01-23 DOI: 10.1002/hlca.202400189
Luciano Barluzzi, Ivica Zivkovic, Farzaneh Fadaei-Tirani, Rodolphe Clérac, Marinella Mazzanti
{"title":"Structure and Magnetic Properties of a Series of Uranium Bis-Siloxide Complexes","authors":"Luciano Barluzzi,&nbsp;Ivica Zivkovic,&nbsp;Farzaneh Fadaei-Tirani,&nbsp;Rodolphe Clérac,&nbsp;Marinella Mazzanti","doi":"10.1002/hlca.202400189","DOIUrl":"https://doi.org/10.1002/hlca.202400189","url":null,"abstract":"<p>Despite their synthetic interest and potential attractive properties, the preparation of heteroleptic U(III) complexes containing monodentate ligands remains challenging. Here we report the synthesis, structure and magnetic properties of three heteroleptic U(III) complexes containing two siloxide donors in the coordination sphere. The bis-siloxide monoiodide complex [U(OSi(O<sup>t</sup>Bu)<sub>3</sub>)<sub>2</sub>I(thf)<sub>3</sub>], <b>1</b> provides a very attractive precursor for accessing heteroleptic complexes and rationally modify the binding angle between the two strongly donating siloxide ligands. Here we reacted <b>1</b> with macrocyclic ligands to yield complexes [[U(OSi(O<sup>t</sup>Bu)<sub>3</sub>)<sub>2</sub>(crypt)]I, <b>3</b> and [[U(OSi(O<sup>t</sup>Bu)<sub>3</sub>)<sub>2</sub>(18c6)]I, <b>4</b>. Magnetic studies of these compounds offer a snapshot on how the SMM properties depend on the local symmetry in the presence of siloxide ligands. The static and dynamic magnetic properties of these compounds reveal a weak dependence of their single-molecule magnet behavior on the local symmetry.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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
Iron-Catalyzed C–H Activation/Aza-Annulation with 2-Butyne for Accessing Methylated Aza-Arenes 铁催化C-H活化/ 2-丁炔环化氮杂芳烃的研究
IF 1.5 4区 化学
Helvetica Chimica Acta Pub Date : 2025-01-22 DOI: 10.1002/hlca.202400200
Yan Zhang, Rui Shang, Eiichi Nakamura
{"title":"Iron-Catalyzed C–H Activation/Aza-Annulation with 2-Butyne for Accessing Methylated Aza-Arenes","authors":"Yan Zhang,&nbsp;Rui Shang,&nbsp;Eiichi Nakamura","doi":"10.1002/hlca.202400200","DOIUrl":"https://doi.org/10.1002/hlca.202400200","url":null,"abstract":"<p>The incorporation of methyl groups into aza-arene frameworks not only often improves their biological activity as the “magic methyl” effect, but also notably affects their solid-state electronic properties by modulating π-π stackings, which makes them promising candidates for developing organic electronic materials. This study focuses on the iron-catalyzed C−H annulation of ketones with 2-butyne via their oxime ethers, offering an efficient pathway to synthesizing methylated π-extended aza-arenes. The reactions utilize isobutyl aluminum(III) catecholate as a base and Triphos (bis(2-diphenylphosphinoethyl)phenylphosphine) as a ligand. Reported C−H activation methods using rhodium catalysis proved less effective with π-conjugated substrates. Regioselective C−H aza-annulation with 1-(trimethylsilyl)propyne following desilylation provides also mono-methylated azaarenes. The reactions also generate tetra-methylated aza-arene products by two-fold C−H aza-annulation on chromeno[3,2-<i>a</i>]xanthene-13,14-dione and quinacridone. These methylated aza-arenes exhibit strong π-π stacking, a narrow emission band, and tunable photophysical properties, indicating their potential applications as electronic materials.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400200","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143840595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Cover Picture: (Helv. Chim. Acta 1/2025) 封面图片：（Helv.）詹。Acta 1/2025)
IF 1.5 4区 化学
Helvetica Chimica Acta Pub Date : 2025-01-17 DOI: 10.1002/hlca.202570101
{"title":"Cover Picture: (Helv. Chim. Acta 1/2025)","authors":"","doi":"10.1002/hlca.202570101","DOIUrl":"https://doi.org/10.1002/hlca.202570101","url":null,"abstract":"<p>\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure>\u0000 </p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202570101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143115516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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