RSS feedhttps://inano.au.dk/about/research-centers-and-projects/cadiacCarbon Dioxide Activation Center (CADIAC) focuses on the conversion of carbon dioxide (CO2) to valuable chemical compounds and is headed by professor Troels Skrydstrup. CADIAC is a Centre of excellence funded from the Danish National Research Foundation.en-gbThu, 28 Mar 2024 10:35:41 +0100Thu, 28 Mar 2024 10:35:41 +0100TYPO3 EXT:newsnews-10125Mon, 25 Mar 2024 08:41:31 +0100Publication in Nature Communications!https://inano.au.dk/about/research-centers-and-projects/cadiac/show/artikel/publication-in-nature-communications-1Have a look at our most recent publication on a palladium-catalyzed electrocarboxylation.Abstract: Carbon isotope labelling of bioactive molecules is essential for accessing the pharmacokinetic and pharmacodynamic properties of new drug entities. Aryl carboxylic acids represent an important class of structural motifs ubiquitous in pharmaceutically active molecules and are ideal targets for the installation of a radioactive tag employing isotopically labelled CO2. However, direct isotope incorporation via the reported catalytic reductive carboxylation (CRC) of aryl electrophiles relies on excess CO2, which is incompatible with carbon-14 isotope incorporation. Furthermore, the application of some CRC reactions for late-stage carboxylation is limited because of the low tolerance of molecular complexity by the catalysts. Herein, we report the development of a practical and affordable Pd-catalysed electrocarboxylation setup. This approach enables the use of near-stoichiometric 14CO2 generated from the primary carbon-14 source Ba14CO3, facilitating late-stage and single-step carbon-14 labelling of pharmaceuticals and representative precursors. The proposed isotope-labelling protocol holds significant promise for immediate impact on drug development programmes.

https://www.nature.com/articles/s41467-024-46820-9

]]>
Research NewsKaroline Thorum Neumann17113524911711352491
news-9986Tue, 20 Feb 2024 08:52:09 +0100Publication in ChemElectroChem.https://inano.au.dk/about/research-centers-and-projects/cadiac/show/artikel/publication-in-chemelectrochem-1Check out our newest publication in collaboration with Kim Daasbjerg's group and Morten Ahlquist's group!Abstract: The increasing concentration of CO2 in the atmosphere and its impact on the climate are matters of significant concern. Extensive research is being conducted on molecular catalysts to electrochemically reduce CO2 into valuable products to disrupt the unidirectional carbon flow. This study compares two manganese bipyridine catalysts, tailored with four or two benzylic diethylamine groups in the secondary coordination sphere. Either of these amine-bearing scaffolds positioned close to the Mn center serves as effective proton relays to facilitate the formation of the corresponding Mn hydride intermediate. Alongside competitive H2 evolution, the reaction of this crucial intermediate with CO2 leads to formate. Our findings underscore the pronounced influence of external Brønsted acids on product selectivity. Notably, when employing the catalyst bearing four amine groups, the HCOO/H2 ratio varies from 81 : 3 with 1.0 M iPrOH to 16 : 64 with 1.0 M PhOH, while the Mn complex adorned with two amine pendant groups consistently favors HCOO, irrespective of the utilized proton sources. Infrared spectroelectrochemistry and density-functional theory calculations unveil distinct disparities in the reactivity of the Mn hydrides toward CO2 due to the change of ligand bulkiness in the two cases. This work substantiates the importance of modulating spatial accessibility while modifying the second sphere encompassing molecular catalysts.

https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/celc.202300553

]]>
Karoline Thorum Neumann17084155291708415529
news-9735Wed, 06 Dec 2023 12:37:04 +0100One more publication in Green Chemistry!https://inano.au.dk/about/research-centers-and-projects/cadiac/show/artikel/one-more-publication-in-green-chemistryHave a look at our most recent publication involving a base-mediated deconstruction of epoxy polymers.Abstract: Fiber-reinforced epoxy composites are key materials for the construction of wind turbine blades and airplanes due to their remarkable mechanical strength properties. On the flipside, their physical and chemical inertness also results in a lack of viable recycling technologies. Recently, tailored resins have been introduced, which allow controlled fragmentation of the polymer matrix and thus the recovery of embedded fibres. However, for the separated thermoset epoxy fragments there is no recycling solution available, resulting in loss of complex molecular structures at their disposal. Here we report a chemical process for recovering bisphenol A (BPA) from epoxy resins, using a mismatched base-solvent system at an elevated temperature. We demonstrate a combinatory disassembly processes / chemical deconstruction strategy on a commercial tailored composite sample, isolating both fibres and the polymer building block. The recovered BPA could potentially be reused in established polymer production chains, thus closing the recycling loop and reducing the need for virgin resources.

https://pubs.rsc.org/en/content/articlelanding/2023/gc/d3gc03707j

]]>
Research NewsKaroline Thorum Neumann17018626241701862624
news-9706Tue, 28 Nov 2023 09:42:45 +0100Publication in Green Chemistry!https://inano.au.dk/about/research-centers-and-projects/cadiac/show/artikel/publication-in-green-chemistryHave a look at our most recent publication on chemical disassembly of elastane fibres.Abstract: The textile industry is ever-growing but only a few recycling options exist for waste fabrics to keep end-of-use clothing articles within the value chain. Generally, these include fibre-to-fibre strategies for pure textiles such as cotton or polyester. However, most textiles comprise blends of fibres which encumbers both mechanical and chemical recycling processes. For example, the polymer elastane is added to increase stretchability in many textiles, whereas polyurethane coatings and membranes partly make up rain clothes, bags and artificial leather items. Here we report the selective disassembly of these two polymers into base chemicals adapting a solvolysis process with tert-amyl alcohol. We showcase the successful depolymerisation of elastane recovered from the dissolution of fabric blends, and also the direct disassembly of elastane containing- or PU-coated textiles with polyamide fabrics. This work opens up new opportunities for the recycling of certain blended textiles.

https://pubs.rsc.org/en/content/articlelanding/2023/gc/d3gc02994h

]]>
Research NewsKaroline Thorum Neumann17011609651701160965
news-9362Thu, 21 Sep 2023 12:58:48 +0200New publication in Eur. J. Org. Chem!https://inano.au.dk/about/research-centers-and-projects/cadiac/show/artikel/new-publication-in-eur-j-org-chemCheck out our latest publication by PhD student Julia on trifluoromethylthiolations!Abstract: Herein, a convenient and operationally simple protocol for the ex-situ generation of bis(trifluoromethyl)disulfide from the readily available and commercial Langlois reagent is reported. The one-step synthesis of the toxic and volatile CF3SSCF3 is performed in a two-chamber reactor with simple PPh3 and N-bromosuccinimide as the activator, allowing for the safe handling and tandem utilization in direct trifluoromethylthiolation reactions. The versatility of the ex-situ generated CF3SSCF3 is demonstrated in known electrophilic, nucleophilic, and a radical trifluoromethylthiolation reactions. Furthermore, the application of the CF3SSCF3 in a copper-catalyzed cross-coupling with boronic acids is disclosed, showing good to excellent yields of trifluoromethyl-substituted aryl products, including pharmaceutically relevant molecules.

https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/ejoc.202300843

]]>
Research NewsKaroline Thorum Neumann16952939281695293928
news-8898Fri, 02 Jun 2023 17:55:15 +0200Award to AU-partnered project for recycling wind turbine bladeshttps://inano.au.dk/about/news-events/news/show/artikel/award-to-au-researchers-for-recycling-wind-turbine-bladesPartners at Aarhus University, the Danish Technological Institute, Olin, and Vestas have received Plastprisen 2023 at Plastindustrien’s anniversary on 25 May at Industriens Hus for their work on developing a method for recycling wind turbine blades through the project, CETEC.Lise Refstrup Linnebjerg Pedersen16857213151685721315news-8774Thu, 27 Apr 2023 10:50:36 +0200First publication in Nature!https://inano.au.dk/about/research-centers-and-projects/cadiac/show/artikel/first-publication-in-nature-1We are extremely happy and proud to share that we have just published our research on catalytic disconnection of C-O bonds in epoxy resins and composites in Nature. A huge congratulations to everyone who has been part of the project! Check out the paper, it is open access. Abstract: Fibre-reinforced epoxy composites are well established in regard to load-bearing applications in the aerospace, automotive and wind power industries, owing to their light weight and high durability. These composites are based on thermoset resins embedding glass or carbon fibres. In lieu of viable recycling strategies, end-of-use composite-based structures such as wind turbine blades are commonly landfilled. Because of the negative environmental impact of plastic waste, the need for circular economies of plastics has become more pressing. However, recycling thermoset plastics is no trivial matter. Here we report a transition-metal-catalysed protocol for recovery of the polymer building block bisphenol A and intact fibres from epoxy composites. A Ru-catalysed, dehydrogenation/bond, cleavage/reduction cascade disconnects the C(alkyl)–O bonds of the most common linkages of the polymer. We showcase the application of this methodology to relevant unmodified amine-cured epoxy resins as well as commercial composites, including the shell of a wind turbine blade. Our results demonstrate that chemical recycling approaches for thermoset epoxy resins and composites are achievable.

https://www.nature.com/articles/s41586-023-05944-6

]]>
Research NewsKaroline Thorum Neumann16825854361682585436
news-8714Thu, 13 Apr 2023 10:02:36 +0200Publication in JACS Au!https://inano.au.dk/about/research-centers-and-projects/cadiac/show/artikel/publication-in-jacs-auWe have just published a research paper in JACS Au involving the catalytic transformation of lignocellulose! It allows the synthesis of methoxyterephthalic acid directly from sawdust! Congratulations to all authors. Abstract: Poly(ethylene terephthalate) polyester represents the most common class of thermoplastic polymers widely used in the textile, bottling, and packaging industries. Terephthalic acid and ethylene glycol, both of petrochemical origin, are polymerized to yield the polyester. However, an earlier report suggests that polymerization of methoxyterephthalic acid with ethylene glycol provides a methoxy-polyester with similar properties. Currently, there are no established biobased synthetic routes toward the methoxyterephthalic acid monomer. Here, we show a viable route to the dicarboxylic acid from various tree species involving three catalytic steps. We demonstrate that sawdust can be converted to valuable aryl nitrile intermediates through hydrogenolysis, followed by an efficient fluorosulfation–catalytic cyanation sequence (>90%) and then converted to methoxyterephthalic acid by hydrolysis and oxidation. A preliminary polymerization result indicates a methoxy-polyester with acceptable thermal properties.

https://pubs.acs.org/doi/10.1021/jacsau.3c00092

]]>
Research NewsKaroline Thorum Neumann16813729561681372956
news-8550Fri, 17 Feb 2023 10:57:42 +0100Publication in ACS Catalysis!https://inano.au.dk/about/research-centers-and-projects/cadiac/show/artikel/publication-in-acs-catalysis-2In collaboration with Kim Daasbjerg's group and Ainara Nova's team we have just published our work on how to control product selectivity in CO2 reduction. A huge congratulations to all authors! Give the paper a read.Abstract: Selective reduction of CO2 is an efficient solution for producing nonfossil-based chemical feedstocks and simultaneously alleviating the increasing atmospheric concentration of this greenhouse gas. With this aim, molecular electrocatalysts are being extensively studied, although selectivity remains an issue. In this work, a combined experimental–computational study explores how the molecular structure of Mn-based complexes determines the dominant product in the reduction of CO2 to HCOOH, CO, and H2. In contrast to previous Mn(bpy-R)(CO)3Br catalysts containing alkyl amines in the vicinity of the Br ligand, here, we report that bpy-based macrocycles locking these amines at the side opposite to the Br ligand change the product selectivity from HCOOH to H2Ab initio molecular dynamics simulations of the active species showed that free rotation of the Mn(CO)3 moiety allows for the approach of the protonated amine to the reactive center yielding a Mn-hydride intermediate, which is the key in the formation of H2 and HCOOH. Additional studies with DFT methods showed that the macrocyclic moiety hinders the insertion of CO2 to the metal hydride favoring the formation of H2 over HCOOH. Further, our results suggest that the minor CO product observed experimentally is formed when CO2 adds to Mn on the side opposite to the amine ligand before protonation. These results show how product selectivity can be modulated by ligand design in Mn-based catalysts, providing atomistic details that can be leveraged in the development of a fully selective system.

https://pubs.acs.org/doi/10.1021/acscatal.2c05951

]]>
Research NewsKaroline Thorum Neumann16766278621676627862
news-8546Thu, 16 Feb 2023 08:49:45 +0100New publication in Synlett!https://inano.au.dk/about/research-centers-and-projects/cadiac/show/artikel/new-publication-in-synlett-1We have just published our work on a nickel-catalyzed carbonylative coupling of alkylzinc reagents and α-bromo-α,α-diflouroacetamides. Congratulations to all authors! Abstract: Herein, we report a nickel catalyzed carbonylative cross coupling of alkyl zinc reagents and α,α-difluorobromoaceamides to obtain α,α,-difluoro-α-ketoamides in moderate to good yields. The reaction is catalyzed by a bench stable nickel(II) pincer complex, in contrast to other reports based on palladium catalysts. The carbonylative reaction is performed in a two-chamber system (COware®), in which carbon monoxide (CO) is generated ex situ from the solid precursor, SilaCOgen, and consumed in the adjacent chamber. The reaction operates at low temperatures using near stoichiometric amounts of CO, and isotopically labeled products are effortlessly accessed as demonstrated using 13C-labeled SilaCOgen.

https://www.thieme-connect.com/products/ejournals/abstract/10.1055/a-2036-4809

]]>
Research NewsKaroline Thorum Neumann16765337851676533785