Jean-Francois Basset, Maurus Marty, Eric Walther, Hervé Mosimann, Harvey Randall, Simon Linder
{"title":"Scalable Preparation of Substituted 4-Aminoquinolines: Advancements in Manufacturing Process Development","authors":"Jean-Francois Basset, Maurus Marty, Eric Walther, Hervé Mosimann, Harvey Randall, Simon Linder","doi":"10.1002/hlca.202400159","DOIUrl":"https://doi.org/10.1002/hlca.202400159","url":null,"abstract":"<p>We report herein an unprecedented and scalable synthetic method for the production of specific aminoquinoline compounds with potential applications as sweetness-enhancing agents. The first strategy involves the reaction of ortho-aminobenzonitriles with β-ketoesters in the presence of stoichiometric amounts of FeCl<sub>3</sub>. Alternatively, the second strategy focuses on an enamine synthesis using alkyl acetoacetate and aminobenzonitrile. The resulting enaminonitrile is then converted into aminoquinoline under basic conditions. This newly developed process yields the desired compounds with an overall yield above 45 % over five steps with high purity.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143113596","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}
Jonas W. Rackl, Alexander F. Müller, Christoph Bärtschi, Helma Wennemers
{"title":"ETHos – A Swiss-Made Open-Source Modular Photoreactor for Laboratory-Scale Photochemical Reactions","authors":"Jonas W. Rackl, Alexander F. Müller, Christoph Bärtschi, Helma Wennemers","doi":"10.1002/hlca.202400154","DOIUrl":"https://doi.org/10.1002/hlca.202400154","url":null,"abstract":"<p>The emergence of photoredox chemistry has enabled the development of previously inaccessible synthetic transformations. Despite the popularity of photoredox chemistry, commercial photoreactors remain expensive. As a result, most academic research groups resort to self-built, not easily replicable reactor designs, jeopardizing the reproducibility and accessibility of photochemical research. To address these issues, this work introduces an easily replicable and modular open-source photoreactor optimized for lab-scale photochemical synthesis. The reactor is operationally simple, operates consistently and reproducibly, and is inexpensive to manufacture. Our design integrates active temperature regulation, an exchangeable vial rack, and customizable light sources into a hybrid structure of machined aluminum, 3D-printed parts, and commercially available components. The open-source reactor with detailed 3D CAD files on GitHub is designed to make research in the field of photochemistry more accessible and reproducible.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 12","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400154","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142860402","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}
{"title":"Diamonds in Chemical Space: The Synthesis of Brexazine","authors":"Leon Rebhan, Ye Buehler, Jean-Louis Reymond","doi":"10.1002/hlca.202400175","DOIUrl":"https://doi.org/10.1002/hlca.202400175","url":null,"abstract":"<p>Here we searched chemical space for small and novel diamond-like, 3D-shaped building blocks, which are very rare but highly valuable for medicinal chemistry because they can increase the natural product likeness of drug molecules and improve their selectivity, water solubility and metabolism. We explored the Generated DataBases (GDBs), which list all possible organic molecules up to a defined size, identified 162 norbornane containing ring systems related to the known trinorbornane, and took inspiration from its simpler substructure brexane to design brexazine as a new chiral and 3D-shaped piperazine analog. The synthesis of brexazine was realized in 11 steps and 11.5 % overall yield from a commercially available norbornene building block. These experiments illustrate the value of exploring chemical space from first principles to design new building blocks for drug discovery.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143112008","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}
Clément Narbonne Zuccarelli, José Laxio-Arenas, Francesco Russo, Nicolas Winssinger
{"title":"Red-Shifted Bioluminescence Using Substrate-Fluorophore Conjugates","authors":"Clément Narbonne Zuccarelli, José Laxio-Arenas, Francesco Russo, Nicolas Winssinger","doi":"10.1002/hlca.202400156","DOIUrl":"https://doi.org/10.1002/hlca.202400156","url":null,"abstract":"<p>NanoLuc (NLuc) is one of the brightest luciferases and has been used in numerous reporter assays and sensor designs. However, its blue light emission (460 nm) is suboptimal for deep tissue imaging or some diagnostic application, and red shifting its emission is desirable. Here, we report the design and synthesis of novel furimazine and coelenterazine analogs conjugated with fluorophores to achieve red-shifted bioluminescence with NLuc and closely related H-Luc via a bioluminescence resonance energy transfer (BRET). Structural insights into NLuc-substrate interactions informed the functionalization of substrates. We report the synthesis of novel substrate-fluorophore conjugates. We show that red-shifted emission was achieved with high BRET ratios. The conjugates are less bright than the parent substrates, but our study highlights the importance of linker length and flexibility for optimizing bioluminescence emission reaching wavelength beyond 600 nm.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143112009","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}
{"title":"Interactions and Click Functionalization of a Poly(Thiophenyl-Tetrazine-Co-Fluorene) Conjugated Polymer with Single-Walled Carbon Nanotubes","authors":"Shagana Kukendran, Sara Salimi, Alex Adronov","doi":"10.1002/hlca.202400146","DOIUrl":"https://doi.org/10.1002/hlca.202400146","url":null,"abstract":"<p>A highly soluble thiophene-based poly(tetrazine) polymer was prepared that can undergo inverse-electron-demand Diels-Alder (IEDDA) click reactions efficiently with different types of <i>trans</i>-cyclooctene (TCO) derivatives resulting in post-polymerization functionalization. The resulting pyridazines post-oxidation exhibited strong interactions with single-walled carbon nanotubes (SWNTs) and showed selectivity toward metallic SWNTs. The resulting dispersions were used to prepare thin films, whose sheet resistivity was measured. It was found that α-amino-ω-methoxy triethylene glycol (TEG) functionalized pyridazine dispersion film resulted in a lower sheet resistance by several orders of magnitude compared to the non-clicked tetrazine dispersion indicating better conductivity post-IEDDA. Furthermore, modification of the polymer backbone while bound to the SWNT was performed successfully, preserving the properties of the nanotubes.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400146","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423572","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}
Dominik Lotter, Annika Huber, Joël Wellauer, Oliver S. Wenger, Christof Sparr
{"title":"Photoinduced Energy Transfer via an Atropisomeric Molecular Bridge","authors":"Dominik Lotter, Annika Huber, Joël Wellauer, Oliver S. Wenger, Christof Sparr","doi":"10.1002/hlca.202400163","DOIUrl":"https://doi.org/10.1002/hlca.202400163","url":null,"abstract":"<p>Atropisomeric scaffolds offer the possibility to predictably position donor and acceptor groups in specific spatial relationships. Herein, a configurationally stable 1,2’-binaphthyl linkage was employed to place a ruthenium(II) tris-(2,2’-bipyridine) complex in proximity to an anthracene moiety to explore how photoinduced triplet-triplet energy transfer can proceed across this type of molecular bridge. An efficient synthesis provided the ruthenium(II)-anthracene dyad with high yields, which allowed to determine characteristic features for the intramolecular energy transfer.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400163","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143111742","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}
Philipp Ludwig, Paul Kilian, Patrick Mayerhofer, Nikolai Hippchen, Frank Rominger, Jan Freudenberg, Uwe H. F. Bunz
{"title":"Stability of Shielded Pentacenes under Ambient Conditions","authors":"Philipp Ludwig, Paul Kilian, Patrick Mayerhofer, Nikolai Hippchen, Frank Rominger, Jan Freudenberg, Uwe H. F. Bunz","doi":"10.1002/hlca.202400161","DOIUrl":"https://doi.org/10.1002/hlca.202400161","url":null,"abstract":"<p>The stabilization of pentacene through variation of substituents serves as a test bed to access stable organic semiconductors, transferable to the larger soluble acenes and azaacenes. Pentacene is stable enough for derivatization via wet-chemistry but sufficiently labile to test its (induced) (photo)decomposition. In this article, we describe the synthesis of shielded pentacenes, either via covalent jacketing with ester macrocycles or via steric shielding with biphenylyl substituents, together with attempts to access a bis(<i>ortho</i>-quaterphenylyl) substituted Geländer pentacene. The photostability of the pentacenes is assessed under ambient conditions (air, light) to simulate handling under typical laboratory conditions and put into perspective with reference compounds, such as TIPS-ethynylated, ether-jacketed or our previously reported Geländer pentacenes.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"108 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hlca.202400161","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143840901","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}
{"title":"Radical C4−H Arylation of 1,4-Dihydropyridines with Cyanoarenes","authors":"Huaixuan Guo, Shiqin Qiu, Peng Xu","doi":"10.1002/hlca.202400162","DOIUrl":"https://doi.org/10.1002/hlca.202400162","url":null,"abstract":"<p>4-Aryl-1,4-dihydropyridines are prevalent pharmacophores and versatile building blocks in medicinal and synthetic chemistry. Herein, we demonstrated a mechanistically distinct radical-radical cross-coupling approach to 4-aryl-1,4-dihydropyridines, via direct C4−H arylation of 1,4-dihydropyridines with readily available cyanoarenes. This mild protocol is initiated by the direct photoexcitation of 1,4-dihydropyridines, eliminating the need for expensive photocatalysts and enabling operation under ambient air conditions.</p>","PeriodicalId":12842,"journal":{"name":"Helvetica Chimica Acta","volume":"107 12","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142861747","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}