Marte Sofie Martinsen Holmsen

• Ravera, Francesco; Holmsen, Marte Sofie Martinsen; Sgarbossa, Paolo; Bourissou, Didier & Biffis, Andrea (2024). Gold(III) Catalysis in Ionic Liquids: The Case Study of Coumarin Synthesis. Advanced Synthesis & Catalysis. ISSN 1615-4150. 367. doi: 10.1002/adsc.202400706. Fulltekst i vitenarkiv Vis sammendrag

  Well-defined (P,C)-cyclometalated Au(III) complexes proved to be able to catalyze the synthesis of coumarins by intramolecular hydroarylation of a broad range of aryl propiolates under mild and practical conditions (0.1–2 mol% catalyst, 25–40 °C, 1–24 hours). The use of an ionic liquid as reaction solvent allowed to drastically decrease the amount of Brönsted acid used to unlock the catalyst regeneration step. The effect of the nature of the acid additive and of the ionic liquid anion have been assessed. Preliminary results on the extension of this methodology to the cyclization of aryl propargyl ethers are also presented.

• Holmsen, Marte Sofie Martinsen; Vesseur, David; García-Rodeja, Yago; Miqueu, Karinne & Bourissou, Didier (2023). σ-Cyclopropyl to π-Allyl Rearrangement at Au^III. Angewandte Chemie International Edition. ISSN 1433-7851. doi: 10.1002/anie.202305280. Fulltekst i vitenarkiv Vis sammendrag

  Abstract The possibility for Au III σ‐cyclopropyl complexes to undergo ring‐opening and give π‐allyl complexes was interrogated. The transformation was first evidenced within (P,C)‐cyclometalated complexes, it occurs within hours at −50 °C. It was then generalized to other ancillary ligands. With (N,C)‐cyclometalated complexes, the rearrangement occurs at room temperature while it proceeds already at −80 °C with a dicationic (P,N)‐chelated complex. Density Functional Theory (DFT) calculations shed light on the mechanism of the transformation, a disrotatory electrocyclic ring‐opening. Intrinsic Bond Orbital (IBO) analysis along the reaction profile shows the cleavage of the distal σ(CC) bond to give a π‐bonded allyl moiety. Careful inspection of the structure and bonding of cationic σ‐cyclopropyl complexes support the possible existence of C−C agostic interactions at Au III .

• Vesseur, David; Holmsen, Marte Sofie Martinsen & Bourissou, Didier (2023). Au(III) π-Allyl Complexes: Synthesis, Structure, Reactivity, and Catalytic Applications. ChemCatChem. ISSN 1867-3880. doi: 10.1002/cctc.202300851. Fulltekst i vitenarkiv Vis sammendrag

  Abstract π‐Allyl complexes of transition metals are key species in organometallic chemistry and homogeneous catalysis. Palladium(II) π‐allyl complexes in particular, have gained a lot of attention, but their isoelectronic gold(III) counterparts long remained elusive. However, this situation changed during the last few years. This concept article describes the preparative routes, characterization, structure and reactivity of such species, together with their catalytic applications. The influence of the ancillary ligand at gold, either (P,C)/(N,C)‐cyclometalated or (P,N)‐hemilabile, is analysed in detail. The Au(III) and Pd(II) π‐allyl complexes are also compared to highlight the similarities and differences.

• Holmsen, Marte Sofie Martinsen; Flores, Ainara Nova & Tilset, Mats (2023). Cyclometalated (N,C) Au(III) Complexes: The Impact of Trans Effects on Their Synthesis, Structure, and Reactivity. Accounts of Chemical Research. ISSN 0001-4842. 56(24), s. 3654–3664. doi: 10.1021/acs.accounts.3c00595. Fulltekst i vitenarkiv Vis sammendrag

  The early years of gold catalysis were dominated by Au(I) complexes and inorganic Au(III) salts. Thanks to the development of chelating ligands, more sophisticated Au(III) complexes can now be easily prepared and handled. The choice of the ancillary ligand has great consequences for the synthesis, properties, and reactivity of the Au(III) complex in question. Among the major factors controlling reactivity are the “trans effect” and the “trans influence” that a ligand imparts at the ligand trans to itself. The kinetic trans effect manifests itself with an increased labilization of the ligand trans to a given ligand and arises from an interplay between ground-state and transition-state effects. The term trans influence, on the other hand, is a ground-state effect only, describing the tendency of a given ligand to weaken the metal–ligand bond trans to itself. Herein, we will use the term “trans effect” to describe both the kinetic and the thermodynamic properties, whereas the term “trans influence” will refer only to thermodynamic properties. We will describe how these trans effects strongly impact the chemistry of the commonly encountered cyclometalated (N,C) Au(III) complexes, a class of complexes we have studied for more than a decade. We found that the outcome of reactions like alkylation, arylation, and alkynylation as well as halide metathesis are dictated by the different trans influence of the two termini of the chelating tpy ligand in (tpy)Au(OAcF)2 (tpy = 2-(p-tolyl)pyridine, OAcF = OCOCF3, tpy-C > tpy-N). There is a strong preference for high trans influence ligands to end up trans to tpy-N, whereas the lower trans influence ligands end up trans to tpy-C. Taking advantage of these preferences, tailor-made (N,C)Au(III) complexes could be prepared. For the functionalization of alkenes at (tpy)Au(OAcF)2, the higher trans effect of tpy-C would suggest that the coordination site trans to tpy-C would be kinetically more available than the one trans to tpy-N. However, due to the thermodynamic preference of having the σ-bonded ligand, resulting from the nucleophilic addition to alkenes, trans to tpy-N, functionalization of alkenes was only observed trans to tpy-N. However, for a catalytic process, the reaction should happen trans to tpy-C, as was observed for the trifluoroacetoxylation of acetylene. When functionalizing acetylene in the coordination site trans to tpy-N, protolytic cleavage of the Au–C(vinyl) bond to release the product did not occur at all, whereas trans to tpy-C protolytic cleavage of the Au–C(vinyl) bond occurred readily, in agreement with the higher trans influence of tpy-C over tpy-N. The large impact of the trans effects in Au(III) complexes is finally exemplified with the synthesis of [(tpy)Au(π-allyl)]+[NTf2]−, which resulted in a highly asymmetric π + σ bonding of the allyl moiety. Here, the bonding is such that the most thermodynamically favorable situation is achieved, with the carbon trans to tpy-N bonded in a σ-fashion and the π-allyl double bond being coordinated trans to tpy-C.

• Regnacq, Matthieu; Lesage, Denis; Holmsen, Marte Sofie Martinsen; Miqueu, Karinne; Bourissou, Didier & Gimbert, Yves (2023). Energetics of key Au(iii)-substrate adducts relevant to catalytic hydroarylation of alkynes. Dalton Transactions. ISSN 1477-9226. 52(38), s. 13528–13536. doi: 10.1039/d3dt02393a. Fulltekst i vitenarkiv Vis sammendrag

  (P,C)-cyclometalated Au(III) complexes have shown remarkable ability to catalyze the intermolecular hydroarylation of alkynes. Evidence of an outer-sphere mechanism has been provided in a previous study and is confirmed here by analysing the experimental data and DFT calculations. In this work, we propose evaluation of critical energies of dissociation of Au(III) complexes with different substrates via energy-resolved mass spectrometry (ERMS) experiments and kinetic modelling. The kinetic model is based on a multi-collisional approach. On the one hand, the classification confirms the mechanism previously proposed; on the other hand, it supports the collisional model and its application to particularly fragile adducts.

• Holmsen, Marte Sofie Martinsen; Blons, Charlie; Amgoune, Abderrahmane; Regnacq, Matthieu; Lesage, Denis & Carrizo, E. Daiann Sosa [Vis alle 10 forfattere av denne artikkelen] (2022). Mechanism of Alkyne Hydroarylation Catalyzed by (P,C)-Cyclometalated Au(III) Complexes. Journal of the American Chemical Society. ISSN 0002-7863. 144, s. 22722–22733. doi: 10.1021/jacs.2c10737. Fulltekst i vitenarkiv Vis sammendrag

  Over the last 5–10 years, gold(III) catalysis has developed rapidly. It often shows complementary if not unique features compared to gold(I) catalysis. While recent work has enabled major synthetic progress in terms of scope and efficiency, very little is yet known about the mechanism of Au(III)-catalyzed transformations and the relevant key intermediates have rarely been authenticated. Here, we report a detailed experimental/computational mechanistic study of the recently reported intermolecular hydroarylation of alkynes catalyzed by (P,C)-cyclometalated Au(III) complexes. The cationic (P,C)Au(OAcF)+ complex (OAcF = OCOCF3) was authenticated by mass spectrometry (MS) in the gas phase and multi-nuclear NMR spectroscopy in solution at low temperatures. According to density functional theory (DFT) calculations, the OAcF moiety is κ2-coordinated to gold in the ground state, but the corresponding κ1-forms featuring a vacant coordination site sit only slightly higher in energy. Side-on coordination of the alkyne to Au(III) then promotes nucleophilic addition of the arene. The energy profiles for the reaction between trimethoxybenzene (TMB) and diphenylacetylene (DPA) were computed by DFT. The activation barrier is significantly lower for the outer-sphere pathway than for the alternative inner-sphere mechanism involving C–H activation of the arene followed by migratory insertion. The π-complex of DPA was characterized by MS. An unprecedented σ-arene Au(III) complex with TMB was also authenticated both in the gas phase and in solution. The cationic complexes [(P,C)Au(OAcF)]+ and [(P,C)Au(OAcF)(σ-TMB)]+ stand as active species and off-cycle resting state during catalysis, respectively. This study provides a rational basis for the further development of Au(III) catalysis based on π-activation.

• Rodriguez, Jessica; Holmsen, Marte Sofie Martinsen; García-Rodeja, Yago; Carrizo, E. Daiann Sosa; Lavedan, Pierre & Mallet-Ladeira, Sonia [Vis alle 8 forfattere av denne artikkelen] (2021). Nucleophilic Addition to π-Allyl Gold(III) Complexes: Evidence for Direct and Undirect Paths. Journal of the American Chemical Society. ISSN 0002-7863. doi: 10.1021/jacs.1c04282. Fulltekst i vitenarkiv
• Witzel, Sina; Holmsen, Marte Sofie; Rudolph, Matthias; Dietl, Martin C.; Øien-Ødegaard, Sigurd & Rominger, Frank [Vis alle 8 forfattere av denne artikkelen] (2020). Simple Mercury-Free Synthesis and Characterization of Symmetric and Unsymmetric Mono-and Dialkynyl (tpy) Au (III) Complexes. Organometallics. ISSN 0276-7333. 39(15), s. 2830–2837. doi: 10.1021/acs.organomet.0c00364. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Nova, Ainara; Øien-Ødegaard, Sigurd; Heyn, Richard H. & Tilset, Mats (2019). A highly asymmetric gold(III) η3‐allyl complex. Angewandte Chemie International Edition. ISSN 1433-7851. 59(4), s. 1516–1520. doi: 10.1002/anie.201912315. Fulltekst i vitenarkiv Vis sammendrag

  A highly asymmetric AuIII η3‐allyl complex has been generated by treating Au(η1‐allyl)Br(tpy) (tpy=2‐(p‐tolyl)pyridine) with AgNTf2. The resulting η3‐allyl complex has been characterized by NMR spectroscopy and X‐ray crystallography. DFT calculations and variable temperature 1H NMR suggest that the allyl ligand is highly fluxional.

• Holmsen, Marte Sofie; Ihlefeldt, Franziska; Øien-Ødegaard, Sigurd; Langseth, Eirin; Wencke, Yannick & Heyn, Richard H. [Vis alle 7 forfattere av denne artikkelen] (2018). Markovnikov at Gold: Nucleophilic Addition to Alkenes at Au(III). Organometallics. ISSN 0276-7333. 37(12), s. 1937–1947. doi: 10.1021/acs.organomet.8b00218. Fulltekst i vitenarkiv Vis sammendrag

  The reactivity of Au(OAcF)2(tpy) (1, OAcF = OCOCF3; tpy = 2-(p-tolyl)pyridine) toward a wide variety of different alkenes with various substitution patterns and different oxygen-based nucleophiles has been investigated. These reactions are two-step processes where a ligand substitution is followed by a nucleophilic addition furnishing Au(III) complexes with C(sp3) ligands. In this work we have found that the reactions always occur trans to tpy-N while the OAcF ligand remains in place trans to tpy-C. The nucleophilic addition takes place exclusively at the most substituted side of the double bond, in a Markovnikov manner, and the nucleophilic addition occurs in an anti fashion as can be seen from the reaction with the 2,3-disubstituted alkene trans-2-hexene. This study has provided valuable insight into the scope and regiochemistry of Au(III) mediated nucleophilic additions, which is of great importance for further development of Au(III) catalysis and alkene functionalization.

• Holmsen, Marte Sofie; Nova, Ainara; Hylland, Knut Tormodssønn; Wragg, David; Øien-Ødegaard, Sigurd & Heyn, Richard H. [Vis alle 7 forfattere av denne artikkelen] (2018). Synthesis of a (N,C,C) Au(III) pincer complex via Csp3–H bond activation: increasing catalyst robustness by rational catalyst design. Chemical Communications. ISSN 1359-7345. 54(79), s. 11104–11107. doi: 10.1039/c8cc05489d. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Nova, Ainara; Balcells, David; Langseth, Eirin; Øien-Ødegaard, Sigurd & Heyn, Richard H. [Vis alle 8 forfattere av denne artikkelen] (2017). trans-Mutation at Gold(III): A mechanistic study of a catalytic acetylene functionalization via a double insertion pathway. ACS Catalysis. 7(8), s. 5023–5034. doi: 10.1021/acscatal.7b01364. Fulltekst i vitenarkiv Vis sammendrag

  The Au(III) complex Au(tpy)(OAcF)2 (OAcF = OCOCF3; tpy = 2-(p-tolyl)pyridine) catalyzes the anti addition of trifluoroacetic acid (HOAcF) to acetylene to furnish vinyl trifluoroacetate. The Au(III) vinyl complex Au(tpy)(OAcF)(CH═CHOAcF) (vinyl group bonded trans to tpy-N) is formed during the early stage of the reaction. The vinyl complex, which has been isolated and structurally characterized, resists protolytic cleavage of the vinyl group, and therefore catalysis does not proceed by a simple formal insertion (i.e., coordination-nucleophilic attack-protolysis at the site trans to tpy-N) mechanism. Experimental evidence, including isotopic labeling, rather suggests that a double-insertion process is operative. The unobserved Au(III) divinyl complex Au(tpy)(CH═CHOAcF)2 is a crucial intermediate for which the true catalytic activity, comprising a coordination-nucleophilic attack-protolysis sequence, occurs at the site trans to tpy-C. The overall mechanism is in full agreement with DFT calculations and is a result of the considerable differences in the kinetic and thermodynamic trans effects of tpy-N versus tpy-C on each reaction step. The computational data provide a rationale for the catalytic functionalization of acetylene trans to tpy-C, whereas ethylene (previously reported) only undergoes a stoichiometric insertion, and then comes to a full stop, trans to tpy-N.

• Holmsen, Marte Sofie; Nova, Ainara; Balcells, David; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tråseth, Eline Aasen [Vis alle 8 forfattere av denne artikkelen] (2016). Small-molecule activation at Au(III): metallacycle construction from ethylene, water and acetonitrile. Dalton Transactions. ISSN 1477-9226. 45(37), s. 14719–14724. doi: 10.1039/c6dt01648k. Fulltekst i vitenarkiv Vis sammendrag

  Incorporation of the simple, readily available, building blocks ethylene, water and acetonitrile into Au(tpy)(OCOCF3)2 (tpy = 2-(p-tolyl)pyridine) in a one-step reaction leads to high yields of a new 6-membered ring gold(III) metallacycle complex. The metallacycle has been characterized spectroscopically and crystallographically, and the mechanism of its formation has been investigated with the aid of DFT calculations.

Se alle arbeider i NVA

• Holmsen, Marte Sofie; Nova, Ainara; Ihlefeldt, Franziska Stefanie; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2017). Small Molecule Activation at Au(III) Complexes. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Nova, Ainara; Wencke, Yannick; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2016). NMR and organometallic chemistry – some examples from Au(III) chemistry. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Ihlefeldt, Franziska Stefanie; Nova, Ainara; Wencke, Yannick; Langseth, Eirin & Øien-Ødegaard, Sigurd [Vis alle 7 forfattere av denne artikkelen] (2016). Au(III) complexes and their reactivity towards alkenes and alkynes. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Ihlefeldt, Franziska Stefanie; Wencke, Yannick; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2016). Au(III) complexes and their reactivity towards alkenes and alkynes. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Ihlefeldt, Franziska Stefanie; Nova, Ainara; Wencke, Yannick; Langseth, Eirin & Øien-Ødegaard, Sigurd [Vis alle 7 forfattere av denne artikkelen] (2016). Au(III) complexes and their reactivity towards alkenes and alkynes. Fulltekst i vitenarkiv
• Ihlefeldt, Franziska Stefanie; Holmsen, Marte Sofie; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2016). Gold(III)-mediated Nucleophilic Addition to Alkenes. Fulltekst i vitenarkiv
• Ihlefeldt, Franziska Stefanie; Holmsen, Marte Sofie; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2016). Gold(III)-mediated Nucleophilic Addition to Alkenes. Fulltekst i vitenarkiv
• Ihlefeldt, Franziska Stefanie; Holmsen, Marte Sofie; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2016). Gold(III)-mediated Nucleophilic Addition to Alkenes. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Ihlefeldt, Franziska Stefanie; Wencke, Yannick; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2016). Au(III) complexes and their reactivity towards alkenes and alkynes. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Ihlefeldt, Franziska Stefanie; Wencke, Yannick; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2015). Au(III) complexes and their reactivity towards alkenes and alkynes. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Ihlefeldt, Franziska Stefanie; Wencke, Yannick; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2015). Au(III) complexes and their reactivity towards alkenes and alkynes. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Ihlefeldt, Franziska Stefanie; Wencke, Yannick; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2015). Au(III) complexes and their reactivity towards alkenes. Fulltekst i vitenarkiv
• Ihlefeldt, Franziska Stefanie; Holmsen, Marte Sofie; Wencke, Yannick; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2015). Gold(III)-mediated nucleophilic addition to alkenes. Fulltekst i vitenarkiv
• Ihlefeldt, Franziska Stefanie; Holmsen, Marte Sofie; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2015). Gold(III)-mediated Nucleophilic Addition to Alkenes. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Ihlefeldt, Franziska Stefanie; Wencke, Yannick; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2015). Insertions of unsaturated molecules into Au-O bonds. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Ihlefeldt, Franziska Stefanie; Wencke, Yannick; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2015). Au(III) complexes and their reactivity towards alkenes and alkynes. Fulltekst i vitenarkiv
• Ihlefeldt, Franziska Stefanie; Holmsen, Marte Sofie; Wencke, Yannick; Langseth, Eirin; Øien-Ødegaard, Sigurd & Tilset, Mats (2015). Alkene insertions at gold. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Gorbitz, Carl Henrik; Øien, Sigurd & Tilset, Mats (2014). Synthesis, Structure and Dynamics of New Rh(III) N-Heterocyclic Carbene Complexes. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Gorbitz, Carl Henrik; Øien, Sigurd & Tilset, Mats (2014). Synthesis, structure and dynamics of new Rh(III) N-heterocyclic carbene complexes. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Gørbitz, Carl Henrik; Øien, Sigurd & Tilset, Mats (2014). Synthesis, structure and dynamics of new Rh(III) N-heterocyclic carbene complexes. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Gorbitz, Carl Henrik; Øien, Sigurd & Tilset, Mats (2014). Synthesis, structure and dynamics of new Rh(III) N-heterocyclic carbene complexes. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie; Tilset, Mats; Nova, Ainara & Heyn, Richard H. (2019). Small-molecule activation at gold: synthesis, characterization, and reactivity of cyclometalated Au(III) complexes. Department of Chemistry. Fulltekst i vitenarkiv
• Holmsen, Marte Sofie (2013). Synthesis, structure and dynamics of new metal N-heterocyclic carbene complexes. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  Metal complexes of N-heterocyclic carbenes are potential useful catalysts and are therefore of large interest. In this master thesis, it was attempted to synthesize several metal complexes bearing a new chelating N-heterocyclic carbene ligand. The synthesis of the planned Ru and Co complexes did not work out as planned, but two new Rh(III) N-heterocyclic carbene complexes were prepared successfully. The synthesis and characterization of the two new Rh(III) complexes is described in detail including NMR, IR, MS and single crystal X-ray analysis. The new complexes show dynamic behavior due to hindered rotation and this was investigated by variable temperature NMR. A DFT optimization of the structure of one of the new Rh(III) complexes was performed and showed good agreement with the experimental structure. The synthesis and characterization of a new Ag(I) N-heterocyclic carbene and a new imidazolium salt, which both are important precursors for preparing the above mentioned metal complexes of N-heterocyclic carbenes is described.

Se alle arbeider i NVA