Organometallics最新文献

{"title":"Back with the Flash Communication","authors":"Paul J. Chirik*, ","doi":"10.1021/acs.organomet.4c0049710.1021/acs.organomet.4c00497","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00497https://doi.org/10.1021/acs.organomet.4c00497","url":null,"abstract":"","PeriodicalId":56,"journal":{"name":"Organometallics","volume":"44 1","pages":"1–2 1–2"},"PeriodicalIF":2.5,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143087786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the Ligand Influence in the Multistep Reaction of Diazoalkanes with Palladium Complexes Leading to Carbene-Aryl Coupling.","authors":"Francisco Villalba, Ana C Albéniz","doi":"10.1021/acs.organomet.4c00439","DOIUrl":"10.1021/acs.organomet.4c00439","url":null,"abstract":"<p><p>The reaction of diphosphino aryl complexes [Pd(C₆F₅)(L-L)(NCMe)](BF₄) (L-L = dppe, dppp, dppb) with diazoalkanes N₂CHR (<i>R</i> = -CH=CHPh, Ph) leads to η³-allyl or η³-benzyl palladium derivatives that are the organometallic products resulting from carbene-aryl coupling. The experimental trend shows that the reaction is favored for dppe > dppp > dppb. It involves several consecutive steps, i.e., diazoalkane coordination, nitrogen extrusion to give a Pd-carbene, and migratory insertion, which are experimentally inseparable, but they can be studied with the help of DFT calculations. The bulkiness and bite angle of the ligand exert a large influence in the relative rate of the steps involved in the reaction, and we have found that carbene formation by N₂ extrusion is the step with the largest barrier for dppe. In contrast, the coordination of the diazoalkane is the most energy-demanding step for the larger dppp and dppb diphosphines. Thus, ligand substitution controls the rate, an important elemental step rarely considered in mechanistic studies of carbene cross coupling reactions. Since diazoalkanes are the most common carbene precursors, either directly or generated from hydrazones, the choice of ligand can be very important to facilitate the entrance of the carbene precursor in the catalytic cycle.</p>","PeriodicalId":56,"journal":{"name":"Organometallics","volume":"44 2","pages":"394-402"},"PeriodicalIF":2.5,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11776105/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the Ligand Influence in the Multistep Reaction of Diazoalkanes with Palladium Complexes Leading to Carbene-Aryl Coupling","authors":"Francisco Villalba,&nbsp; and ,&nbsp;Ana C. Albéniz*,&nbsp;","doi":"10.1021/acs.organomet.4c0043910.1021/acs.organomet.4c00439","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00439https://doi.org/10.1021/acs.organomet.4c00439","url":null,"abstract":"<p >The reaction of diphosphino aryl complexes [Pd(C₆F₅)(L-L)(NCMe)](BF₄) (L-L = dppe, dppp, dppb) with diazoalkanes N₂CHR (<i>R</i> = −CH═CHPh, Ph) leads to η³-allyl or η³-benzyl palladium derivatives that are the organometallic products resulting from carbene-aryl coupling. The experimental trend shows that the reaction is favored for dppe &gt; dppp &gt; dppb. It involves several consecutive steps, i.e., diazoalkane coordination, nitrogen extrusion to give a Pd-carbene, and migratory insertion, which are experimentally inseparable, but they can be studied with the help of DFT calculations. The bulkiness and bite angle of the ligand exert a large influence in the relative rate of the steps involved in the reaction, and we have found that carbene formation by N₂ extrusion is the step with the largest barrier for dppe. In contrast, the coordination of the diazoalkane is the most energy-demanding step for the larger dppp and dppb diphosphines. Thus, ligand substitution controls the rate, an important elemental step rarely considered in mechanistic studies of carbene cross coupling reactions. Since diazoalkanes are the most common carbene precursors, either directly or generated from hydrazones, the choice of ligand can be very important to facilitate the entrance of the carbene precursor in the catalytic cycle.</p>","PeriodicalId":56,"journal":{"name":"Organometallics","volume":"44 2","pages":"394–402 394–402"},"PeriodicalIF":2.5,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.organomet.4c00439","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143088091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neptunium Pyridine Dipyrrolide Complexes","authors":"Leyla R. Valerio,&nbsp;Andrew W. Mitchell,&nbsp;Lauren M. Lopez,&nbsp;Matthias Zeller,&nbsp;Suzanne C. Bart* and Ellen M. Matson*,&nbsp;","doi":"10.1021/acs.organomet.4c0047210.1021/acs.organomet.4c00472","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00472https://doi.org/10.1021/acs.organomet.4c00472","url":null,"abstract":"<p >Two pyridine dipyrrolide neptunium(IV) complexes, (^MesPDP^Ph)NpCl₂(THF) and Np(^MesPDP^Ph)₂, where (^MesPDP^Ph)^2– is the doubly deprotonated form of 2,6-bis(5-(2,4,6-trimethylphenyl)-3-phenyl-1<i>H</i>-pyrrol-2-yl)pyridine, have been prepared. Characterization of the complexes has been performed through a combination of solid- and solution-state methods, including single-crystal X-ray diffraction and electronic absorption and nuclear magnetic resonance spectroscopies. Collectively, these data confirm the formation of the mono- and bis-ligated species. Electrochemistry of a series of bis-ligated actinide complexes, An(^MesPDP^Ph)₂ (An = Th, U, Np), is presented.</p>","PeriodicalId":56,"journal":{"name":"Organometallics","volume":"44 2","pages":"439–446 439–446"},"PeriodicalIF":2.5,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.organomet.4c00472","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neptunium Pyridine Dipyrrolide Complexes.","authors":"Leyla R Valerio, Andrew W Mitchell, Lauren M Lopez, Matthias Zeller, Suzanne C Bart, Ellen M Matson","doi":"10.1021/acs.organomet.4c00472","DOIUrl":"10.1021/acs.organomet.4c00472","url":null,"abstract":"<p><p>Two pyridine dipyrrolide neptunium(IV) complexes, (^MesPDP^Ph)NpCl₂(THF) and Np(^MesPDP^Ph)₂, where (^MesPDP^Ph)^2- is the doubly deprotonated form of 2,6-bis(5-(2,4,6-trimethylphenyl)-3-phenyl-1<i>H</i>-pyrrol-2-yl)pyridine, have been prepared. Characterization of the complexes has been performed through a combination of solid- and solution-state methods, including single-crystal X-ray diffraction and electronic absorption and nuclear magnetic resonance spectroscopies. Collectively, these data confirm the formation of the mono- and bis-ligated species. Electrochemistry of a series of bis-ligated actinide complexes, An(^MesPDP^Ph)₂ (An = Th, U, Np), is presented.</p>","PeriodicalId":56,"journal":{"name":"Organometallics","volume":"44 2","pages":"439-446"},"PeriodicalIF":2.5,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11776103/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Divergent Reactivity of Azides and Diazoalkanes Toward Ferrous Complexes and Isolation of a FeIII Carbene Radical Complex","authors":"Ethan Zars,&nbsp;Lisa Pick,&nbsp;Achala Kankanamge,&nbsp;Michael R. Gau,&nbsp;Patrick J. Carroll,&nbsp;Samantha N. MacMillan,&nbsp;Kyle M. Lancaster*,&nbsp;Karsten Meyer* and Daniel J. Mindiola*,&nbsp;","doi":"10.1021/acs.organomet.4c0047110.1021/acs.organomet.4c00471","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00471https://doi.org/10.1021/acs.organomet.4c00471","url":null,"abstract":"<p >Treatment of [(^<i>t</i>Bupyrr₂pyr)Fe(OEt₂)] (<b>1</b>-OEt₂) (^<i>t</i>Bupyrr₂pyr^2– = 3,5-^<i>t</i>Bu₂-bis(pyrrolyl)pyridine) with trimethylsilyl azide (N₃SiMe₃) and subsequent photolysis at 390 nm results in clean formation of [(^<i>t</i>BupyrrpyrpyrrNHSiMe₃)Fe] (<b>2</b>) as the result of a nitrene being inserted into a <i>tert</i>-butyl C–H bond of the ^<i>t</i>Bupyrr₂pyr ligand. Treatment of <b>1</b>-OEt₂ with azidotrimethyltin (N₃SnMe₃), however, results in isolation of the γ-bound azide adduct ferrous complex, [(^<i>t</i>Bupyrr₂pyr)Fe(N₃SnMe₃)] (<b>1</b>-N₃SnMe₃). When treated with diphenyl diazomethane (Ph₂CN₂), complex <b>1</b>-OEt₂ converts to the iron carbene complex [(^<i>t</i>Bupyrr₂pyr)FeCPh₂] (<b>1</b>-CPh₂), and the X-ray structure revealed a Fe–CPh₂ bond length of 1.964(3) Å. A room temperature magnetic moment of <b>1</b>-CPh₂ indicates an <i>S</i> = 2 spin state, consistent with a high-spin Fe^III center antiferromagnetically coupled to a carbene radical anion (CPh₂^•–). Zero-field ⁵⁷Fe Mössbauer spectroscopy and Fe K-edge X-ray absorption spectroscopy confirm this assignment. In solution, complex <b>1</b>-CPh₂ rearranges to [{^<i>t</i>BupyrrpyrC(═CPh₂)-C(CMe₃)═CH–C(CMe₃)═N}Fe]₂ (<b>3</b>) resulting from carbene insertion into the 1-position of the pyrrolide arm of the ^<i>t</i>Bupyrr₂pyr ligand and dimerization. Complex <b>3</b> possesses two high-spin Fe^II centers according to ⁵⁷Fe Mössbauer spectroscopy, with antiferromagnetic coupling between the spin centers. Monitoring the conversion of <b>1</b>-CPh₂ to <b>3</b> by UV–vis spectroscopy reveals this process to be first order in <b>1</b>-CPh₂ with a highly ordered transition state evidenced by activation parameters: Δ<i>S</i>^‡ = −87.6 ± 25.8 J·mol^–1·K^–1 and Δ<i>H</i>^‡ = 63.1 ± 8.3 kJ·mol^–1.</p>","PeriodicalId":56,"journal":{"name":"Organometallics","volume":"44 2","pages":"427–438 427–438"},"PeriodicalIF":2.5,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zerovalent Triphosphine Ruthenium Complexes for Coupling Carbon Dioxide and Ethylene","authors":"Tristan T. Adamson,&nbsp;Laura G. Reeder,&nbsp;Steven P. Kelley and Wesley H. Bernskoetter*,&nbsp;","doi":"10.1021/acs.organomet.4c0043310.1021/acs.organomet.4c00433","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00433https://doi.org/10.1021/acs.organomet.4c00433","url":null,"abstract":"<p >The coupling of carbon dioxide and ethylene to generate value-added chemicals has been part of recent fundamental advances to improve sustainability in commercial chemical synthons. A formal zerovalent triphosphine-ligated ruthenium complex, (^<i>t</i>BuP(CH₂CH₂PEt₂)₂)Ru(κ-<i>S</i>-DMSO)(C₂H₄), was found to promote CO₂ functionalization, affording products derived from both a 1:1 and 1:2 ethylene to CO₂ coupling stoichiometry. The equimolecular coupling reaction selectively afforded a five-membered ruthenium lactone species, (^<i>t</i>BuP(CH₂CH₂PEt₂)₂)Ru(κ-<i>S</i>-DMSO)(κ-<i>C</i>,κ-<i>O</i>-CH₂CH₂CO₂), under low CO₂ pressure. At higher CO₂ pressure, the ruthenium lactone complex activated a second equivalent of CO₂, yielding a dimeric methylmalonate ruthenium compound, [(^<i>t</i>BuP(CH₂CH₂PEt₂)₂)Ru(μ₂, κ¹-<i>O</i>, κ²-<i>O</i>,<i>O</i>-O₂CCHCH₃CO₂)]₂. Both carbon dioxide activation products were characterized by X-ray diffraction. Preliminary mechanistic studies suggest that reversible β-H elimination is a key process in the conversion between the two ruthenium carboxylate species. A rare, formally zerovalent ruthenium coordination compound stabilized only by ethylene and DMSO ligands was also isolated and characterized.</p>","PeriodicalId":56,"journal":{"name":"Organometallics","volume":"44 2","pages":"385–393 385–393"},"PeriodicalIF":2.5,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theoretical Insight into Cp*Ir-Catalyzed Upgrading of Ethanol to n-Butanol: The Crucial Role of Cs2CO3","authors":"Linlin Yang,&nbsp;Cheng Zhang,&nbsp;Yingzhi Ren,&nbsp;Zhao-Xu Chen* and Guixiang Zeng*,&nbsp;","doi":"10.1021/acs.organomet.4c0044610.1021/acs.organomet.4c00446","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00446https://doi.org/10.1021/acs.organomet.4c00446","url":null,"abstract":"<p >The ethanol-to-<i>n</i>-butanol upgrading process catalyzed by a Cp*Ir complex (<b>1-Ir</b>) and mild base Cs₂CO₃ was investigated using density functional theory calculations. Initially, Cs₂CO₃ and <b>1-Ir</b> form an active species <b>2</b> with an exothermicity of 12.9 kcal/mol. Ethanol dehydrogenation then occurs through the cooperation of the Ir center and Cs₂CO₃ to produce an Ir–H complex <b>3</b> with the release of acetaldehyde and CsHCO₃. Cs₂CO₃ catalyzes the aldol condensation of acetaldehyde to produce a C₄ intermediate crotonaldehyde. Subsequently, the successive hydride and proton migrations occur from <b>3</b> and ethanol to crotonaldehyde, respectively, to produce butanal. The proton migration step is the rate-determining step (Δ<i>G</i>^‡/Δ<i>G</i> = 29.1/–12.1 kcal/mol). Finally, <i>n</i>-butanol is produced via transfer hydrogenation of butanal with ethanol catalyzed by Cs₂CO₃. High selectivity for <i>n</i>-butanol is due to preferential hydrogenation of crotonaldehyde over its further condensation into C₆ species. Cs₂CO₃ plays a critical role in promoting ethanol dehydrogenation, aldol condensation, and butanal hydrogenation. In contrast, Na₂CO₃ significantly reduces reaction efficiency mainly due to its weaker basicity in the aldol condensation of acetaldehyde. These findings provide insights into the ethanol-to-<i>n</i>-butanol conversion and offer a foundation for developing milder bases for the reaction.</p>","PeriodicalId":56,"journal":{"name":"Organometallics","volume":"44 2","pages":"410–417 410–417"},"PeriodicalIF":2.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143090924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bis(Tetrathiafulvalenes) with Mixed Phosphine and Silane Double Bridges","authors":"Axel Houssin,&nbsp;Ion Danila,&nbsp;Frédéric Biaso,&nbsp;Magali Allain,&nbsp;Michel Geoffroy,&nbsp;Flavia Pop,&nbsp;Marco Caricato and Narcis Avarvari*,&nbsp;","doi":"10.1021/acs.organomet.4c0032010.1021/acs.organomet.4c00320","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00320https://doi.org/10.1021/acs.organomet.4c00320","url":null,"abstract":"<p >Covalently linked bis(TTFs) (TTF = tetrathiafulvalene) are interesting electron donor precursors that allow the investigation of the extent of intramolecular electronic communication between the two redox active units and the access to mixed valence states. Here we describe the straightforward synthesis of the first rigid bis(TTFs) fused through six- or seven-membered-ring heterocycles containing two different heteroatomic bridges. The mixed phosphino/silane compound (PPh)(SiMe₂)(<i>o</i>-DMTTF)₂ <b>1</b> (<i>o</i>-DMTTF = <i>ortho</i>-dimethyl-tetrathiafulvalene) shows a distorted central phosphasilyline ring in the solid state and a planar and a moderately folded TTF. Compound <b>2</b> contains a seven member ring due to SiMe₂ and Me₂Si–SiMe₂ bridges and it crystallized in two polymorphic forms. The electrochemical study of <b>1</b> indicates sequential reversible oxidation into a mixed valence radical cation and then dication, with a peak-to-peak separation of 110 mV, thus suggesting through-bond electronic communication between the fused TTF units, as confirmed by EPR measurements of the radical cation <b>1</b>^<b>+•</b>. Further, charge-transfer complex <b>1</b>•TCNQ has been obtained as single crystals. The presence of a single phosphino bridge in <b>1</b> allowed the preparation of a mononuclear platinum(II) complex containing two such bis(TTF) ligands, <i>trans</i> located in the coordination sphere of the metal center.</p>","PeriodicalId":56,"journal":{"name":"Organometallics","volume":"44 2","pages":"363–372 363–372"},"PeriodicalIF":2.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ligand Substitution, Catalyst Activation, and Oxidative Addition Studies of a Stable Dialkyl Palladium Precatalyst","authors":"Ian C. Chagunda,&nbsp;Antonia Kropp,&nbsp;David C. Leitch* and J. Scott McIndoe*,&nbsp;","doi":"10.1021/acs.organomet.4c0046310.1021/acs.organomet.4c00463","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00463https://doi.org/10.1021/acs.organomet.4c00463","url":null,"abstract":"<p >Palladium-catalyzed cross-coupling reactions are indispensable in chemical synthesis, but efficient <i>in situ</i> catalyst activation remains a persistent challenge. Current Pd(II) precatalysts often lead to inefficient catalyst activation, necessitating higher catalyst loadings and limiting selectivity. We investigated the ligand substitution and activation mechanism of the stable Pd(II) dialkyl complex (^DMPDAB)Pd(CH₂SiMe₃)₂ in real-time using mass spectrometric monitoring. The introduction of charge-tagged phosphine ligands enabled the detection of key catalytic intermediates and identification of off-cycle species. Our findings demonstrate a low activation energy for the ligand dissociation of the ^DMPDAB ligand and the reductive elimination of (Me₃SiCH₂)₂ resulting in rapid formation of monoligated LPd(0) species, the active catalytic species for oxidative addition. These mechanistic insights offer a path toward developing more efficient and selective Pd-catalyzed processes, offering valuable guidance for the future design of precatalysts with improved performance.</p>","PeriodicalId":56,"journal":{"name":"Organometallics","volume":"44 5","pages":"628–636 628–636"},"PeriodicalIF":2.5,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143576450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}