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Cover Picture: (Helv. Chim. Acta 11/2023) 封面图片：（Helv.）
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-11-27 DOI: 10.1002/hlca.202371101
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引用次数: 0
Probing the Nature of Surface Hydrides by Deuterium Quadrupolar Parameters: A Case Study on Silica-Supported Zirconium Hydrides 用氘四极性参数探讨表面氢化物的性质:以二氧化硅支撑的氢化锆为例
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-11-23 DOI: 10.1002/hlca.202300173
Scott R. Docherty, Philipp Schärz, Domenico Gioffrè, Alexander V. Yakimov, Christophe Copéret
{"title":"Probing the Nature of Surface Hydrides by Deuterium Quadrupolar Parameters: A Case Study on Silica-Supported Zirconium Hydrides","authors":"Scott R. Docherty,&nbsp;Philipp Schärz,&nbsp;Domenico Gioffrè,&nbsp;Alexander V. Yakimov,&nbsp;Christophe Copéret","doi":"10.1002/hlca.202300173","DOIUrl":"10.1002/hlca.202300173","url":null,"abstract":"<p>Supported metal hydrides are key reactive intermediates in various catalytic processes, such as hydrogenation and dehydrogenation, but are often challenging to characterize spectroscopically. Here, deuterium solid state nuclear magnetic resonance spectroscopy is used to understand the structure of the corresponding silica-supported zirconium hydrides after H/D exchange as an illustrative example of supported metal hydrides, which have been shown to display notable reactivity towards small molecules (<i>e. g</i>., CO<sub>2</sub> and N<sub>2</sub>O) and to activate both C−H and C−C bonds, hence their use in to the conversion of hydrocarbons (alkanes, polyolefins <i>etc</i>.)</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202300173","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138496106","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
HFIP Mediated Synthesis of C4-Aryl-2-quinolones through Serial Oxidation HFIP介导的连续氧化合成c4 -芳基-2-喹诺酮类药物
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-11-21 DOI: 10.1002/hlca.202300153
Seung Hoon Lee, Minseok Kang, Hyung Min Chi
{"title":"HFIP Mediated Synthesis of C4-Aryl-2-quinolones through Serial Oxidation","authors":"Seung Hoon Lee,&nbsp;Minseok Kang,&nbsp;Hyung Min Chi","doi":"10.1002/hlca.202300153","DOIUrl":"10.1002/hlca.202300153","url":null,"abstract":"<p>A practical, efficient approach for the synthesis of C4-arylated 2-quinolones from propargylic chlorides and anilines has been developed. The synthesis process involves subsequent oxidations of the initial products, tetrahydroquinolines and quinolinium ions, eventually leading to desired quinolones. A mechanism for the transformation is proposed based on a meticulous examination of intermediates and comprehensive control experiments. With a thorough understanding of the reaction mechanism, the applicability of the reaction scope is expanded.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"106 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138496105","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
Development of Photoredox-Assisted Direct α-Alkylation Reactions of Ketones with Arylalkenes Using a Catalytic Amount of LiOtBu as a Brønsted Base 光氧化还原辅助酮与芳烯直接a-烷基化反应的研究
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-11-20 DOI: 10.1002/hlca.202300139
Tsubasa Hirata, Tomoya Hisada, Yoshihiro Ogasawara, Shū Kobayashi, Yasuhiro Yamashita
{"title":"Development of Photoredox-Assisted Direct α-Alkylation Reactions of Ketones with Arylalkenes Using a Catalytic Amount of LiOtBu as a Brønsted Base","authors":"Tsubasa Hirata,&nbsp;Tomoya Hisada,&nbsp;Yoshihiro Ogasawara,&nbsp;Shū Kobayashi,&nbsp;Yasuhiro Yamashita","doi":"10.1002/hlca.202300139","DOIUrl":"10.1002/hlca.202300139","url":null,"abstract":"<p>Photoinduced direct α-alkylation reactions of ketones with arylalkenes using an organophotocatalyst and a Brønsted base were developed. It was found that the choice of both Brønsted base and photocatalyst was crucial, and in the presence of catalytic amounts of 2,4,6-tris(diphenylamino)-3,5-difluorobenzonitrile (3DPA2FBN) and LiO<sup><i>t</i></sup>Bu, the desired reactions of ketones with styrene analogues proceeded smoothly under blue-LED light irradiation to afford the products in moderate to high yields. This method constitutes an atom-economical alkylation process for α-functionalization of both cyclic and acyclic ketones.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202300139","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138496130","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
Scalable Preparation of 1-Aminoethyl Oxindoles From Simple Benzaldehydes 由简单苯甲醛大规模制备1-氨基乙基氧吲哚
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-11-16 DOI: 10.1002/hlca.202300188
Cédric Bürki, Stefan Diethelm, Fabio D'Aiuto, Marco Künzli, Gaëlle Mathieu, Christine Schmitt
{"title":"Scalable Preparation of 1-Aminoethyl Oxindoles From Simple Benzaldehydes","authors":"Cédric Bürki,&nbsp;Stefan Diethelm,&nbsp;Fabio D'Aiuto,&nbsp;Marco Künzli,&nbsp;Gaëlle Mathieu,&nbsp;Christine Schmitt","doi":"10.1002/hlca.202300188","DOIUrl":"10.1002/hlca.202300188","url":null,"abstract":"<p>Oxindoles are prevalent structures in natural products and pharmaceutically active molecules. To support structure–activity-relationship (SAR) studies in a medicinal chemistry program, we developed a straightforward and scalable synthesis route to 1-aminoethyl oxindole building blocks harboring various types of substituents. Our strategy relies on an intramolecular Buchwald–Hartwig amidation of a 2-bromophenylacetic amide precursor. The cyclization substrates can be prepared from readily available benzaldehydes by <i>ortho</i>-selective C(sp<sup>2</sup>)−H bromination followed by homologation to the corresponding phenylacetic acid derivatives. The process was optimized to allow for preparation of 246 g of one representative example.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138496129","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
Improved Synthesis of Chiral 1,4,7-Triazacyclononane Derivatives and Their Application in Ni-Catalyzed Csp3−Csp3 Kumada Cross-Coupling 手性1,4,7-三氮杂环壬烷衍生物的改进合成及其在ni催化Csp3-Csp3 Kumada交叉偶联中的应用
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-11-15 DOI: 10.1002/hlca.202300170
Chi-Herng Hu, Ju Byeong Chae, Liviu M. Mirica
{"title":"Improved Synthesis of Chiral 1,4,7-Triazacyclononane Derivatives and Their Application in Ni-Catalyzed Csp3−Csp3 Kumada Cross-Coupling","authors":"Chi-Herng Hu,&nbsp;Ju Byeong Chae,&nbsp;Liviu M. Mirica","doi":"10.1002/hlca.202300170","DOIUrl":"10.1002/hlca.202300170","url":null,"abstract":"<p>Herein, we report four new chiral 1,4,7-triazacyclononane (TACN) derivatives and their corresponding nickel(II) chloride complexes. All TACN ligands are bearing one chiral N-substituent and two alkyl (methyl or <i>tert</i>-butyl) N-substituents, and we have developed a new synthetic method for the dimethyl-substituted TACN derivative, in order to prevent the rotational isomers that hinder the cyclization reaction. The nickel complexes change their coordination geometry significantly depending on the steric bulk of the N-alkyl substituents, from a dinuclear tris(μ-chloro)dinickel complex to mononuclear Ni-dichloride and Ni-chloride complexes. These complexes were then employed in the alkyl-alkyl Kumada cross-coupling reaction and revealed that the more sterically hindered ligands produced more homocoupled product rather than the cross-coupled product, while the mononuclear Ni-dichloride complex exhibited significantly lower catalytic activity. These chiral complexes were also employed in enantioconvergent cross-coupling reactions as well, to afford significant enantioenrichment. Overall, the least sterically hindered Ni complex yields the best yields in the alkyl-alkyl Kumada cross-coupling reaction among the four complexes investigated, as well as the highest enantioselectivity.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202300170","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138496128","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 Olfactory Properties of Lower-Ring Homologues of the Linear Alicyclic Musk Romandolide 线性脂环麝香罗曼内酯低环同系物的合成及其嗅觉特性
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-11-14 DOI: 10.1002/hlca.202300181
Vladimír Dacho, Artem Nikipelov, Michaela Tóthová, Philip Kraft, Peter Szolcsányi
{"title":"Synthesis and Olfactory Properties of Lower-Ring Homologues of the Linear Alicyclic Musk Romandolide","authors":"Vladimír Dacho,&nbsp;Artem Nikipelov,&nbsp;Michaela Tóthová,&nbsp;Philip Kraft,&nbsp;Peter Szolcsányi","doi":"10.1002/hlca.202300181","DOIUrl":"10.1002/hlca.202300181","url":null,"abstract":"<p>In order to expand the knowledge on linear alicyclic musks, a set of 29 small-ring (racemic) analogues of the biodegradable and renewable alicyclic musk <i>Romandolide</i> was designed, prepared, and evaluated. The common short and modular synthesis employs either commercially available or easily accessible (substituted) cyclopropyl/cyclobutyl ketones and acids. These were transformed in three/four steps to the target compounds. Their qualitative olfactory analysis reveals that contraction of cyclohexane ring of <i>Romandolide</i> to smaller rings annihilates the genuine musk scent, though many of these share the metallic hot-iron off-note of some macrocyclic musks. Indeed, these new derivatives exhibit a plethora of pleasant, interesting, and potentially useful scents including herbal, green, fruity, or chocolate ones accompanied by various undertones. The powdery, fruity ionone odor of the dimethyl cyclobutyl compound was found to be most interesting as it possesses a very natural raspberry and violet character. Computational modelling suggest that the lowest-energy conformers of the target compounds do either not adopt a true U-shape as was speculated to be a prerequisite for a musk odor, or that the quaternary carbon atom of the dimethyl-substituted cyclobutane is not well placed to fit into a hydrophobic binding pocket on the corresponding receptor site.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134991192","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
Keap It in the Family: How to Fish out New Paradigms in Keap1-Mediated Cell Signaling Keap家族：如何探索Keap1介导的细胞信号传导新范式
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-11-13 DOI: 10.1002/hlca.202300154
Marcus J. C. Long, Kuan-Ting Huang, Yimon Aye
{"title":"Keap It in the Family: How to Fish out New Paradigms in Keap1-Mediated Cell Signaling","authors":"Marcus J. C. Long,&nbsp;Kuan-Ting Huang,&nbsp;Yimon Aye","doi":"10.1002/hlca.202300154","DOIUrl":"10.1002/hlca.202300154","url":null,"abstract":"<p>Keap1 is associated with cytoprotective signaling. These roles of Keap1 typically focus on its role as a degrader of the antioxidant response (AR) transcription factor, Nrf2, and the inhibition of this process upon Keap1 labeling by electrophiles. However, work from several laboratories has reemphasized both the important role of Nrf2 binding in negatively regulating AR, and the fact that electrophile Keap1 modification dissociates Nrf2 from Keap1. This model appears to be applicable to other signaling modes regulated by Keap1. Here, we use recent data we have derived using experiments in zebrafish and cultured cells to discuss different models of Keap1 regulation.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"106 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202300154","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136282635","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
Tailoring the Hybridization Density of DNA Biosensors through Tunable Surface Functionalization 通过可调表面功能化定制 DNA 生物传感器的杂交密度
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-11-13 DOI: 10.1002/hlca.202300150
Perrine Robin, Lucas Mayoraz, Pauline Skigin, Mounir Mensi, Sandrine Gerber-Lemaire
{"title":"Tailoring the Hybridization Density of DNA Biosensors through Tunable Surface Functionalization","authors":"Perrine Robin,&nbsp;Lucas Mayoraz,&nbsp;Pauline Skigin,&nbsp;Mounir Mensi,&nbsp;Sandrine Gerber-Lemaire","doi":"10.1002/hlca.202300150","DOIUrl":"10.1002/hlca.202300150","url":null,"abstract":"<p>DNA biosensors are promising candidates for the development of point-of-care diagnosis methods. They can be inserted in microfluidic platforms, are often non-expensive, and can be produced for a variety of targeted analytes. However, their development faces several challenges, some of which arise from their surface design. Among the characteristics which affect the binding efficiency of DNA probes to their targeted genes, the packing density and lateral spacing of the probe sequences must be controlled to provide enough binding sites and avoid crowding effect. It has also been demonstrated that increasing the space between the probe and the substrate can enhance the sensitivity of the sensing surface. Herein, we describe a methodology to control the vertical distance between DNA probes and a glass support, and lateral spacing between the probes. Such functionalization strategy could help the development of sensing surface with high hybridization density, and therefore high sensitivity.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202300150","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136281838","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
A Practical and Scalable Non-Photonic Decarboxylative C−N Coupling of Bicyclo[1.1.1]Pentane Carboxylate by Leveraging High Throughput Experimentation 利用高通量实验实现双环[1.1.1]戊烷羧酸盐的实用、可扩展的非光子脱羧 C-N 偶联反应
IF 1.8 4区 化学
Helvetica Chimica Acta Pub Date : 2023-11-04 DOI: 10.1002/hlca.202300158
Nathan J. Gesmundo, Lei Shi, Russell C. Smith
{"title":"A Practical and Scalable Non-Photonic Decarboxylative C−N Coupling of Bicyclo[1.1.1]Pentane Carboxylate by Leveraging High Throughput Experimentation","authors":"Nathan J. Gesmundo,&nbsp;Lei Shi,&nbsp;Russell C. Smith","doi":"10.1002/hlca.202300158","DOIUrl":"10.1002/hlca.202300158","url":null,"abstract":"<p>Research towards the development of novel synthetic methods to access substituted bicyclo[1.1.1]pentane (BCP) structural motifs has been conducted by both academic groups and industrial organizations. Recent developments have been strongly focused on the utility of visible light catalysis to promote a cornucopia of radical-based transformations, including incorporation of BCP motifs. While these methods have proven powerful in accessing various substitution patterns, some scalability challenges remain. Herein we describe a focused effort on the high-throughput experimentation (HTE) guided optimization of a decarboxylative <i>non-photonic</i> coupling that can be conducted using traditional batch reactors. Employing an unanticipated mixture of copper(I) chloride and cyclopentyl methyl ether (CPME) results in the formation of a <i>N</i>-substituted bicyclo[1.1.1]pentyl pyrazole product while limiting the overall equivalency of the hypervalent iodonium precursor.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"106 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135774329","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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