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Cover Picture: (Helv. Chim. Acta 1/2024) 封面图片： (Helv. Chim. Acta 1/2024)
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2024-01-16 DOI: 10.1002/hlca.202470101
{"title":"Cover Picture: (Helv. Chim. Acta 1/2024)","authors":"","doi":"10.1002/hlca.202470101","DOIUrl":"https://doi.org/10.1002/hlca.202470101","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":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202470101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139473989","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
Enhancing the Metalating Power of ZnEt2 via Formation of an Alkyl/Alkoxide Potassium Zincate 通过形成烷基/烷氧基锌酸钾增强 ZnEt2 的金属化能力
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2024-01-12 DOI: 10.1002/hlca.202300237
Jasmin Kocher, Neil R. Judge, Eva Hevia
{"title":"Enhancing the Metalating Power of ZnEt2 via Formation of an Alkyl/Alkoxide Potassium Zincate","authors":"Jasmin Kocher,&nbsp;Neil R. Judge,&nbsp;Eva Hevia","doi":"10.1002/hlca.202300237","DOIUrl":"10.1002/hlca.202300237","url":null,"abstract":"<p>Advancing the use of alkali-metal alkoxides as additives to activate organometallic reagents, here we report the synthesis and characterization of a novel potassium zincate [{(PMDETA)KZn(O<i>t</i>Bu)Et<sub>2</sub>}<sub>2</sub>] obtained by co-complexation of equimolar amounts of potassium <i>tert</i>-butoxide, diethyl zinc and the tridentate donor PMDETA (<i>N,N,N’,N’’,N’’</i>-pentamethyldiethylenetriamine). Demonstrating its ability to activate both of the Et groups towards alkyne C−H metalation, this zincate reacts at room temperature with 2 equivalents of phenylacetylene to furnish [(THF)<sub>2</sub>KZn(CCPh)<sub>2</sub>(O<i>t</i>Bu)}<sub>2</sub>], whereas, for the homometallic [ZnEt<sub>2</sub>(TMEDA)] (TMEDA=<i>N,N,N’,N’</i>-tetramethylethylendiamine) only one Et group is reactive towards the same substrate under the same conditions. Investigations on the reactivity of these complexes to undergo N−H amine metalation using 2, 6-diisopropylphenylamine (NH<sub>2</sub>Dipp) and 1,2,3,4-tetrahydroquinoline (THQ(H)) as model substrates revealed that while homometallic [ZnEt<sub>2</sub>(TMEDA)] is completely inert towards these amines, heterobimetallic [{(PMDETA)KZn(O<i>t</i>Bu)Et<sub>2</sub>}<sub>2</sub>] reacts through one of its Et groups to form [(THF)<sub>2</sub>KZn(O<i>t</i>Bu)(Et)(NHDipp)] as well as [(THF)<sub>4</sub>K<sub>2</sub>Zn(THQ)<sub>4</sub>]. The latter is obtained as a side product of ligand redistribution of a putative [(THF)<sub>n</sub>KZn(O<i>t</i>Bu)(Et)(THQ)] intermediate. An alternative method to access mixed amide/alkoxide potassium zincates is also described by assessing the co-complexation of KO<i>t</i>Bu with Zn(HMDS)<sub>2</sub> in the presence of PMDETA which gave [(PMDETA)KZn(HMDS)<sub>2</sub>(O<i>t</i>Bu)].</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202300237","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139462529","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
Selective Recognition of Aromatic Amino Acids by a Molecular Cleft in Water 分子裂隙在水中选择性识别芳香族氨基酸
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2024-01-10 DOI: 10.1002/hlca.202300221
Joël F. Keller, Michal Valášek, Marcel Mayor
{"title":"Selective Recognition of Aromatic Amino Acids by a Molecular Cleft in Water","authors":"Joël F. Keller,&nbsp;Michal Valášek,&nbsp;Marcel Mayor","doi":"10.1002/hlca.202300221","DOIUrl":"10.1002/hlca.202300221","url":null,"abstract":"<p>The development of water-soluble hosts for the selective recognition of aromatic amino acids is highly desirable and may serve as a tool to facilitate drug discovery and enable fabrication of sensors for point-of-care monitoring in the context of phenylketonuria disease. This paper presents the synthesis and characterization of a water-soluble molecular cleft which is demonstrated to selectively bind aromatic amino acid guests over other amino acids in aqueous medium, favoring ʟ-Trp over ʟ-Phe and ʟ-Tyr by a factor of approximately five. Host/guest-interaction forces were studied by <sup>1</sup>H-NMR titrations complemented by fluorescence titrations and isothermal titration calorimetry. The here presented results provide a starting point for future optimizations in our efforts to selectively identify and quantify individual aromatic amino acids in aqueous medium.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202300221","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139439409","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 and Photophysical Evaluation of 3,3’-Nitrogen Bis-Substituted fac-[Re(CO)3(Diimine)Br] Complexes 3,3'-氮双取代面-[Re(CO)3(二亚胺)Br] 配合物的合成与光物理评估
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2024-01-09 DOI: 10.1002/hlca.202300239
Joshua Csucker, Nathalie Decrausaz, Sarah Isabella Jäggi, Olivier Blacque, Bernhard Spingler, Roger Alberto
{"title":"Synthesis and Photophysical Evaluation of 3,3’-Nitrogen Bis-Substituted fac-[Re(CO)3(Diimine)Br] Complexes","authors":"Joshua Csucker,&nbsp;Nathalie Decrausaz,&nbsp;Sarah Isabella Jäggi,&nbsp;Olivier Blacque,&nbsp;Bernhard Spingler,&nbsp;Roger Alberto","doi":"10.1002/hlca.202300239","DOIUrl":"10.1002/hlca.202300239","url":null,"abstract":"<p>The preparations, photophysical and electrochemical properties of a series of <i>fac</i>-[Re(CO)<sub>3</sub>(diimine)Br] complexes are presented. The bipyridine (bpy) based diimine ligands feature symmetrical and asymmetrical 3,3’-diamino-2,2’-bipyridine substitution patterns. Photophysical and electrochemical properties of these complexes are tunable, depending on their organic diimine framework. Introduction of a distal urea bridge <i>via</i> the 3,3’-substitution pattern led to prolonged phosphorescence lifetimes without a significant change in absorbance and phosphorescence emission wavelengths. Reversible electrochemical bipyridine reduction remained largely unchanged by this derivatization.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202300239","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139412242","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
Chiral Quaternary Ammonium Salt-Catalyzed Enantioselective Addition Reactions of Hydantoins 手性季铵盐催化的海因对映体选择性加成反应
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-12-28 DOI: 10.1002/hlca.202300234
Katharina Röser, Lucas Prameshuber, Sajid Jahangir, Sharath Chandra Mallojjala, Jennifer S. Hirschi, Mario Waser
{"title":"Chiral Quaternary Ammonium Salt-Catalyzed Enantioselective Addition Reactions of Hydantoins","authors":"Katharina Röser,&nbsp;Lucas Prameshuber,&nbsp;Sajid Jahangir,&nbsp;Sharath Chandra Mallojjala,&nbsp;Jennifer S. Hirschi,&nbsp;Mario Waser","doi":"10.1002/hlca.202300234","DOIUrl":"10.1002/hlca.202300234","url":null,"abstract":"<p>We herein report a protocol for the asymmetric 1,4-addition of hydantoins to various Michael acceptors by utilizing Cinchona alkaloid-based chiral quaternary ammonium salt catalysts. Various products were obtained with moderate to good enantioselectivities and accompanying computational investigations helped to identify key interactions responsible for the observed selectivity. DFT calculations along with non-covalent interaction plots reveal the presence of numerous stabilizing non-classical hydrogen bonding interactions along with other non-covalent interactions between the chiral quaternary ammonium salt and hydantoin molecule in the C−C bond forming transition states leading to the formation of the products. In addition, a first proof-of-concept for an analogous a-sulfanylation reaction, albeit with poor selectivity, is reported as well.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202300234","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139065626","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
Radicals and Carbohydrates: A Grand Alliance 自由基与碳水化合物大联盟
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-12-21 DOI: 10.1002/hlca.202300218
Béatrice Quiclet-Sire, Samir Z. Zard
{"title":"Radicals and Carbohydrates: A Grand Alliance","authors":"Béatrice Quiclet-Sire,&nbsp;Samir Z. Zard","doi":"10.1002/hlca.202300218","DOIUrl":"10.1002/hlca.202300218","url":null,"abstract":"<p>This review describes applications of radical reactions developed in the authors’ laboratory for the modification of carbohydrates. It focuses on tin-free variation on the Barton-McCombie deoxygenation; on reductive de-iodination; on intermolecular radical additions of xanthates; on allylations and vinylations of xanthates and iodides, with emphasis on allylations using allylic alcohols activated as fluoropyridyl ethers; and, finally, on the synthesis of mercaptosugars.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138825643","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 12/2023) 封面图片：（Helv.）
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-12-19 DOI: 10.1002/hlca.202371201
{"title":"Cover Picture: (Helv. Chim. Acta 12/2023)","authors":"","doi":"10.1002/hlca.202371201","DOIUrl":"10.1002/hlca.202371201","url":null,"abstract":"<p>\u0000 \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":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202371201","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138822413","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
Strategies for Direct, Transition Metal-Free Addition of Nitrogen Synthons to Alkenes 无过渡金属氮合成物与烯烃直接加成的策略
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-12-15 DOI: 10.1002/hlca.202300160
Brett N. Hemric, Thalia A. Garcia, Adriana E. Barni
{"title":"Strategies for Direct, Transition Metal-Free Addition of Nitrogen Synthons to Alkenes","authors":"Brett N. Hemric,&nbsp;Thalia A. Garcia,&nbsp;Adriana E. Barni","doi":"10.1002/hlca.202300160","DOIUrl":"10.1002/hlca.202300160","url":null,"abstract":"<p>The incorporation of nitrogen into small molecules is one of the highest-demanded transformations in modern synthetic chemistry. Alkene difunctionalization and aziridination offer desirable approaches to the incorporation of these amino synthons from feedstock precursors. Although amino groups can be added to alkenes following alkene reaction with an initiation reagent, the most desirable approach involves direct addition of the nitrogen group to the alkene, allowing for a range of possible secondary functionalization outcomes. Although many of these strategies have been accomplished through the use of transition metals, the utility of a transition metal-free approach is still at the forefront of synthetic chemistry, both in development and demand. This review aims to present a comprehensive review of the history and current state-of-the-art in the transition metal-free, direct addition of nitrogen to alkenes.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138690116","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
Playing with Protic Additives to Improve the Outcome of Rhodium-Catalyzed Hydroarylation of Fullerene C60 with Arylboronic Acids 利用原生添加剂改善富勒烯 C60 与芳基硼酸的铑催化加氢反应结果
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-12-15 DOI: 10.1002/hlca.202300206
Merve Ergun Dönmez, Måns Eriksson, Gustav Hulu, Michael Nordström, Helena Grennberg
{"title":"Playing with Protic Additives to Improve the Outcome of Rhodium-Catalyzed Hydroarylation of Fullerene C60 with Arylboronic Acids","authors":"Merve Ergun Dönmez,&nbsp;Måns Eriksson,&nbsp;Gustav Hulu,&nbsp;Michael Nordström,&nbsp;Helena Grennberg","doi":"10.1002/hlca.202300206","DOIUrl":"10.1002/hlca.202300206","url":null,"abstract":"<p>A new one-phase process for hydroarylation of C<sub>60</sub> fullerene using arylboronic acids and a rhodium catalyst in an aromatic solvent containing soluble protic additives is described. Yields of monohydroarylated product with tert-butanol and water as the protic additive range from 14 to 50 % depending on which arylboronic acid is used after reaction times of 4 hours or less which is a significant improvement from the outcome of reactions carried out using conditions from the literature. Accurate monitoring of reaction outcomes was achieved by a combination of UV-Vis spectroscopy and <sup>1</sup>H-NMR spectroscopy: C<sub>60</sub> conversion was determined using an analytical HPLC-UV-vis method employing commonly available columns for the separation, while product formation was quantified by <sup>1</sup>H-NMR spectroscopy with an internal standard. Moreover, two new arylboronic acids carrying 4-alkynyl aryl substituents, synthesized using Sonogashira couplings, are reported, as well as the use of these in the hydroarylation of C<sub>60</sub>.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202300206","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138689858","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
Hydroalkylation of 1,1-Diarylalkenes Mediated by Magnesium Hydride in Ethereal Solvents 乙太溶剂中氢化镁介导的 1,1-二芳基烯烃氢烷基化反应
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-12-14 DOI: 10.1002/hlca.202300212
Nattawadee Chaisan, Eugene Yew Kun Tan, Shunsuke Chiba
{"title":"Hydroalkylation of 1,1-Diarylalkenes Mediated by Magnesium Hydride in Ethereal Solvents","authors":"Nattawadee Chaisan,&nbsp;Eugene Yew Kun Tan,&nbsp;Shunsuke Chiba","doi":"10.1002/hlca.202300212","DOIUrl":"10.1002/hlca.202300212","url":null,"abstract":"<p>A method for the hydroalkylation of 1,1-diarylalkenes has been developed using magnesium hydride (MgH<sub>2</sub>) generated <i>in situ</i> by the solvothermal treatment of magnesium iodide (MgI<sub>2</sub>) with sodium hydride (NaH) in ethereal solvents. The process is initiated by the hydromagnesiation of 1,1-diarylalkenes with MgH<sub>2</sub> to generate 1,1-diarylethylmagnesium species, which are immediately alkylated with ethereal solvents to construct a diaryl quaternary carbon center in the hydroalkylation products.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138689987","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
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