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Accueil > Les équipes > Méthodes et Applications en Chimie Organique (MACO) > Publications

Publications

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2022


  • « Boron, silicon, nitrogen and sulfur-based contemporary precursors for the generation of alkyl radicals by single electron transfer and their synthetic utilization - Chemical Society Reviews (RSC Publishing) », 2022. [Online]. Available: https://pubs.rsc.org/en/content/articlelanding/2022/cs/d1cs01084k. [Accessed: 31-janv.-2023].
    Mots-clés : CHEMBIO, MACO, POLE 1, POLE 3.


  • V. Corcé, C. Ollivier, et L. Fensterbank, « Boron, silicon, nitrogen and sulfur-based contemporary precursors for the generation of alkyl radicals by single electron transfer and their synthetic utilization », Chemical Society Reviews, vol. 51, nᵒ 4, p. 1470-1510, févr. 2022.
    Résumé : Recent developments in the use of boron, silicon, nitrogen and sulfur derivatives in single-electron transfer reactions for the generation of alkyl radicals are described. Photoredox catalyzed, electrochemistry promoted or thermally-induced oxidative and reductive processes are discussed highlighting their synthetic scope and discussing their mechanistic pathways.
    Mots-clés : CHEMBIO, MACO, POLE 1, POLE 3.


  • T. Deis, J. Forte, L. Fensterbank, et G. Lemière, « Synthesis and Reactivity of Martin’s Spirosilane-Derived Chloromethylsilicate », Molecules, vol. 27, nᵒ 6, p. 1767, janv. 2022.
    Résumé : Pentacoordinate silicon derivatives with a chloromethyl ligand are versatile compounds that are usually obtained from the corresponding tetravalent trialkoxy- or trihalogeno(chloromethyl)silane. We describe herein the synthesis of a chloromethylsilicate bearing two Martin’s ligands readily obtained by addition of in situ generated chloromethyllithium to a spirosilane. The reactivity of this new species was evaluated and it has been established that the chloride is displaced by strong nucleophiles such as alkyllithiums and (hetero)aryllithiums. In Lewis acidic conditions, the pentacoordinate silicon species rearranges through a formal insertion of a methylene into one Si–C bond, to form a new tetravalent spirosilane with a six-membered ring. The same kind of rearrangement can be triggered also by addition of a Lewis base. The mechanism of the rearrangement in both conditions has been studied by means of DFT calculations.
    Mots-clés : DFT calculations, MACO, pentacoordination, POLE 1, Sila-Matteson rearrangement, silicon, spirosilane.


  • T. Deis, J. Maury, F. Medici, M. Jean, J. Forte, N. Vanthuyne, L. Fensterbank, et G. Lemière, « Synthesis and Optical Resolution of Configurationally Stable Zwitterionic Pentacoordinate Silicon Derivatives », Angewandte Chemie International Edition, vol. 61, nᵒ 3, p. e202113836, 2022.
    Résumé : Stereogenic silicon centres in functionalised tetracoordinated organosilanes generally exhibit very high configurational stability under neutral conditions. This stability drops completely when higher coordination states of the silicon centre are reached due to rapid substituent exchange. Herein we describe the synthesis of chiral and neutral pentacoordinate silicon derivatives with high configurational stability. The zwitterionic nature of these air- and water-tolerant species allows for the first time their direct and efficient optical resolution using chiral HPLC techniques. By means of this method, pentacoordinate silicon compounds exhibiting high Si-inversion have been obtained as single enantiomers. A rationalisation of the enantiomerisation pathways has been also carried out using DFT calculations.
    Mots-clés : Chiral HPLC, Chirality, MACO, Optical resolution, POLE 1, Silicon, Zwitterion.


  • A. Millanvois, C. Ollivier, et L. Fensterbank, « Bis(catecholato)silicates: Synthesis and Structural Data », European Journal of Inorganic Chemistry, vol. 2022, nᵒ 17, p. e202101109, 2022.
    Résumé : This minireview provides an overview of the synthesized bis(catecholato)silicates based on the nature of the alkyl or aryl residues and associated cations as well as the methods developed for this purpose. Structural and analytical data such as the 29Si NMR shift of silicon penta- and hexacoordinate derivatives, selected examples of crystal structures by X-ray diffraction analysis and oxidation potentials of silicates are reported. Some aspects of reactivity are also mentioned.
    Mots-clés : Bis(catecholo)silicate, Hypercoordinated silicon, MACO, Oxidation potential, POLE 1, Silicon NMR, X-ray analysis.


  • O. Sadek, M. Abdellaoui, A. Millanvois, C. Ollivier, et L. Fensterbank, « Organometallic catalysis under visible light activation: benefits and preliminary rationales », Photochemical & photobiological sciences, vol. 21, nᵒ 4, p. 585-606, avr. 2022.
    Résumé : Organometallic catalysis under visible light activation is an emerging field. Activation by photosensitization or by direct light absorption of organometallic complexes can facilitate or trigger elementary steps in a catalytic cycle such as pre-catalyst reduction, oxidative addition, transmetalation and reductive elimination, as well as the ability of generating radical intermediates, widening the structural diversity offered by classical couplings. This perspective aims to highlight key examples of these light-induced or enhanced processes, with an emphasis on the underlying mechanisms involved.
    Mots-clés : MACO, POLE 1.


  • T. E. Schirmer, M. Abdellaoui, A. Savateev, C. Ollivier, M. Antonietti, L. Fensterbank, et B. König, « Mesoporous Graphitic Carbon Nitride as a Heterogeneous Organic Photocatalyst in the Dual Catalytic Arylation of Alkyl Bis(catecholato)silicates », Organic Letters, vol. 24, nᵒ 13, p. 2483-2487, avr. 2022.
    Résumé : Mesoporous graphitic carbon nitride (mpg-CN) is introduced as a heterogeneous photocatalyst to perform dual photoredox- and nickel-catalyzed cross-coupling reactions between alkyl bis(catecholato)silicates as radical precursors and aryl or alkenyl bromides. The synergy between this recyclable photocatalyst and the broadly applied homogeneous nickel complex [Ni(dtbbpy)Br2] gives access to C(sp2)–C(sp3) cross-coupling products in a sustainable fashion. The recycled mpg-CN photocatalyst was analyzed by time-resolved emission spectroscopy and EPR spectroscopy.
    Mots-clés : MACO, POLE 1.


  • F. Zhao, M. Abdellaoui, W. Hagui, M. Ballarin-Marion, J. Berthet, V. Corcé, S. Delbaere, H. Dossmann, A. Espagne, J. Forté, L. Jullien, T. Le Saux, V. Mouriès-Mansuy, C. Ollivier, et L. Fensterbank, « Reactant-induced photoactivation of in situ generated organogold intermediates leading to alkynylated indoles via Csp2-Csp cross-coupling », Nature Communications, vol. 13, nᵒ 1, p. 2295, avr. 2022.
    Résumé : Photosensitization of organogold intermediates is an emerging field in catalysis. In this context, an access to 2,3-disubstituted indoles from o-alkynyl aniline and iodoalkyne derivatives via a gold-catalyzed sequence under visible-light irradiation and in the absence of an exogenous photocatalyst was uncovered. A wide scope of the process is observed. Of note, 2-iodo-ynamides can be used as electrophiles in this cross-coupling reaction. The resulting N-alkynyl indoles lend themselves to post-functionalization affording valuable scaffolds, notably benzo[a]carbazoles. Mechanistic studies converge on the fact that a potassium sulfonyl amide generates emissive aggregates in the reaction medium. Static quenching of these aggregates by a vinylgold(I) intermediate yields to an excited state of the latter, which can react with an electrophile via oxidative addition and reductive elimination to forge the key C-C bond. This reactant-induced photoactivation of an organogold intermediate opens rich perspectives in the field of cross-coupling reactions.
    Mots-clés : CHEMBIO, CSOB, MACO, Photocatalysis, POLE 1, POLE 3, Reaction mechanisms.


  • F. Zhao, W. Hagui, M. Ballarín-Marión, C. Ollivier, V. Mouriès-Mansuy, et L. Fensterbank, « 3-Sulfonylindoles via Gold- or Silver-Catalyzed Cyclization─1,3-Sulfonyl Migration Sequences under Visible Light Irradiation », ACS Organic & Inorganic Au, sept. 2022.
    Résumé : A pathway for the synthesis of 3-sulfonylindoles has been devised. Upon blue LED irradiation, in the presence of a gold(I) or a silver(I) salt, ortho-alkynyl N-sulfonyl precursors readily undergo a 5-endo-dig cyclization concomitant with a 1,3-sulfonyl migration. While the gold-catalyzed reaction takes place in photocatalyst-free conditions, an iridium photocatalyst (Ir[dF(CF3)ppy]2(dtbbpy)PF6) is necessary with silver catalysis. Mechanistic studies featuring the generation of a sulfonyl radical support this dichotomy.
    Mots-clés : MACO, POLE 1.

2021



  • T. Deis, F. Medici, A. Poussard-Schulz, G. Lemière, et L. Fensterbank, « Synthesis and reactivity of an anionic NHC-borane featuring a weakly coordinating silicate anion », Journal of Organometallic Chemistry, vol. 956, p. 122120, déc. 2021.
    Résumé : We report herein the synthesis of a new NHC-stabilised borane complex featuring a weakly coordinating anion, namely a pentaorganosilicate, on the NHC backbone. The synthesis can be achieved from a zwitterionic abnormal silicate-imidazolium adduct by deprotonation with a strong base followed by quenching with a borane transfer agent. Alternatively, the IPr-BH3 complex can also be deprotonated and the resulting vinylanion is trapped by a tetravalent spirosilane. The first structural data on a lithium derivative of an anionic NHC-borane complex functionalized by a silicate have been obtained and reveal an interaction between the three hydrogens of the borane and the lithium cation. Assessment of the reactivity highlights the higher hydridicity of the anionic NHC-borane compared to the parent IPr-BH3. Finally, electronic properties of this new species have been evaluated by means of DFT calculations and the presence of the silicate on the NHC backbone raises the HOMO which can in part explain the high hydride-donor abilities. This is consistent with the smooth reduction of an aldehyde without Lewis acid additive.
    Mots-clés : Anionic NHC, DFT calculations, MACO, NHC-borane, Pentacoordinated compounds, POLE 1, Silicon, Spirosilane.


  • L. Fensterbank et C. Ollivier, Introduction: Radicals, from Gomberg to Planet Mars, 1st editionᵉʳ éd. Thieme Verlag, 2021.
    Résumé : Thieme E-Books & E-Journals
    Mots-clés : MACO, POLE 1.


  • L. Fensterbank, C. Ollivier, A. Roblin, et M. Barbazanges, « Chiral Counterions in Enantioselective Organometallic Catalysis », in Topics in Enantioselective Catalysis, vol. Volume 9, WORLD SCIENTIFIC, 2021, p. 95-122.


  • E. Levernier, K. Jaouadi, H. - R. Zhang, V. Corcé, A. Bernard, G. Gontard, C. Troufflard, L. Grimaud, E. Derat, C. Ollivier, et L. Fensterbank, « Phenyl Silicates with Substituted Catecholate Ligands: Synthesis, Structural Studies and Reactivity », Chemistry – A European Journal, vol. 27, nᵒ 34, p. 8782-8790, 2021.
    Résumé : While the generation of aryl radicals by photoredox catalysis under reductive conditions is well documented, it has remained challenging under an oxidative pathway. Because of the easy photo-oxidation of alkyl bis-catecholato silicates, a general study of phenyl silicates bearing substituted catecholate ligands has been achieved. The newly synthesized phenyl silicates have been fully characterized, and their reactivity has been explored. It was found that, thanks to the substitution of the catecholate moiety, notably with the 4-cyanocatecholato ligand, the phenyl radical could be generated and trapped. Computational studies provided a rationale for these findings.
    Mots-clés : aryl radicals, CHEMBIO, MACO, oxidation, photoredox catalysis, POLE 1, POLE 3, silicates.


  • B. Neil, F. Lucien, L. Fensterbank, et C. Chauvier, « Transition-Metal-Free Silylation of Unactivated C(sp2)–H Bonds with tert-Butyl-Substituted Silyldiazenes », ACS Catalysis, vol. 11, nᵒ 21, p. 13085-13090, nov. 2021.
    Résumé : Aromatic organosilanes bearing C(sp2)–Si bonds have found increasing applications across the chemical science, yet are mostly produced by atom-uneconomical stoichiometric procedures. Catalytic alternatives using hydrosilanes as silicon sources have also been described, but they display unfavorable thermodynamics and are mostly based on expensive catalytic systems, often derived from noble metals, or lack generality. Herein, we describe the use of an alternative silicon source, namely the tert-butyl-substituted silyldiazenes (tBu–N═N–SiR3), that are readily accessible from commercially available precursors and whose structure enables the C(sp2)–H bond silylation of unactivated heteroaryl and aryl compounds under ambient, transition-metal-free catalytic conditions.
    Mots-clés : MACO, POLE 1.

2020


  • Y. Ren, J. Forte, K. Cheaib, N. Vanthuyne, L. Fensterbank, H. Vezin, M. Orio, S. Blanchard, et M. Desage-El Murr, « Optimizing Group Transfer Catalysis by Copper Complex with Redox-Active Ligand in an Entatic State », Iscience, vol. 23, nᵒ 3, p. UNSP 100955, mars 2020.
    Résumé : Metalloenzymes use earth-abundant non-noble metals to perform high-fidelity transformations in the biological world. To ensure chemical efficiency, metalloenzymes have acquired evolutionary reactivity-enhancing tools. Among these, the entatic state model states that a strongly distorted geometry induced by ligands around a metal center gives rise to an energized structure called entatic state, strongly improving the reactivity. However, the original definition refers both to the transfer of electrons or chemical groups, whereas the chemical application of this concept in synthetic systems has mostly focused on electron transfer, therefore eluding chemical transformations. Here we report that a highly strained redox-active ligand enables a copper complex to perform catalytic nitrogen- and carbon-group transfer in as fast as 2 min, thus exhibiting a strong increase in reactivity compared with its unstrained analogue. This report combines two reactivity-enhancing features from metalloenzymes, entasis and redox cofactors, applied to group-transfer catalysis.
    Mots-clés : aziridination, cu, E-POM, galactose-oxidase, generation, MACO, metal-complexes, models, oxidation, POLE 1, POLE 2, radicals, reactivity, site.

2019



  • V. Corcé, C. Lévêque, C. Ollivier, et L. Fensterbank, « 15 Silicates in Photocatalysis », in Photocatalysis in Organic Synthesis, 1st editionᵉʳ éd., Thieme Verlag, 2019.
    Résumé : Bis(catecholato)silicates have emerged as robust alkyl radical sources under photocatalysis. This chapter describes the preparation of various silicates and their utilization under photocatalytic conditions for the formation of C–C and C–O bonds. The last section focuses on the use of silicates in photoredox/nickel dual catalysis.
    Mots-clés : CHEMBIO, MACO, POLE 3.


  • J. Jacquet, L. Fensterbank, et M. Desage-El Murr, « Trifluoromethylation and Related Reactions », in Non-Noble Metal Catalysis, John Wiley & Sons, Ltd, 2019, p. 329-354.
    Résumé : Among the ever-increasing variety of transformations catalyzed by earth-abundant metals, introduction of fluorine-containing groups is at the forefront of current synthetic interests. The resulting products find widespread applications from agrochemicals to pharmaceuticals, and this versatility plays no mean part in the wealth of methods that are currently being developed. The most recent contributions to this fast-paced field are presented hereafter and should provide the reader with an overview of the latest developments.
    Mots-clés : copper, MACO, nickel, perfluoroalkylation, POLE 1, trifluoromethylation, trifluoromethylthiolation.

2018


  • « N-Heterocyclic carbene-stabilized gold nanoparticles with tunable sizes - Dalton Transactions (RSC Publishing) », Dalton Transactions, 2018. [Online]. Available: https://pubs.rsc.org/en/content/articlelanding/2018/dt/c8dt00416a. [Accessed: 31-janv.-2023].


  • H. Patel, M. Periyasamy, G. P. Sava, A. Bondke, B. W. Slafer, S. H. B. Kroll, M. Barbazanges, R. Starkey, S. Ottaviani, A. Harrod, E. O. Aboagye, L. Buluwela, M. J. Fuchter, A. G. M. Barrett, R. C. Coombes, et S. Ali, « ICEC0942, an Orally Bioavailable Selective Inhibitor of CDK7 for Cancer Treatment », Molecular Cancer Therapeutics, vol. 17, nᵒ 6, p. 1156-1166, mai 2018.
    Résumé : Recent reports indicate that some cancer types are especially sensitive to transcription inhibition, suggesting that targeting the transcriptional machinery provides new approaches to cancer treatment. Cyclin-dependent kinase (CDK)7 is necessary for transcription, and acts by phosphorylating the C-terminal domain (CTD) of RNA polymerase II (PolII) to enable transcription initiation. CDK7 additionally regulates the activities of a number of transcription factors, including estrogen receptor (ER)-α. Here we describe a new, orally bioavailable CDK7 inhibitor, ICEC0942. It selectively inhibits CDK7, with an IC50 of 40 nmol/L; IC50 values for CDK1, CDK2, CDK5, and CDK9 were 45-, 15-, 230-, and 30-fold higher. In vitro studies show that a wide range of cancer types are sensitive to CDK7 inhibition with GI50 values ranging between 0.2 and 0.3 μmol/L. In xenografts of both breast and colorectal cancers, the drug has substantial antitumor effects. In addition, combination therapy with tamoxifen showed complete growth arrest of ER-positive tumor xenografts. Our findings reveal that CDK7 inhibition provides a new approach, especially for ER-positive breast cancer and identify ICEC0942 as a prototype drug with potential utility as a single agent or in combination with hormone therapies for breast cancer. ICEC0942 may also be effective in other cancers that display characteristics of transcription factor addiction, such as acute leukaemia and small-cell lung cancer. Mol Cancer Ther; 17(6); 1156–66. ©2018 AACR.
    Mots-clés : MACO, POLE 1.

2017



  • P. Hazel, S. H. B. Kroll, A. Bondke, M. Barbazanges, H. Patel, M. J. Fuchter, R. C. Coombes, S. Ali, A. G. M. Barrett, et P. S. Freemont, « Inhibitor Selectivity for Cyclin-Dependent Kinase 7: A Structural, Thermodynamic, and Modelling Study », ChemMedChem, vol. 12, nᵒ 5, p. 372-380, 2017.
    Résumé : Deregulation of the cell cycle by mechanisms that lead to elevated activities of cyclin-dependent kinases (CDK) is a feature of many human diseases, cancer in particular. We identified small-molecule inhibitors that selectively inhibit CDK7, the kinase that phosphorylates cell-cycle CDKs to promote their activities. To investigate the selectivity of these inhibitors we used a combination of structural, biophysical, and modelling approaches. We determined the crystal structures of the CDK7-selective compounds ICEC0942 and ICEC0943 bound to CDK2, and used these to build models of inhibitor binding to CDK7. Molecular dynamics (MD) simulations of inhibitors bound to CDK2 and CDK7 generated possible models of inhibitor binding. To experimentally validate these models, we gathered isothermal titration calorimetry (ITC) binding data for recombinant wild-type and binding site mutants of CDK7 and CDK2. We identified specific residues of CDK7, notably Asp155, that are involved in determining inhibitor selectivity. Our MD simulations also show that the flexibility of the G-rich and activation loops of CDK7 is likely an important determinant of inhibitor specificity similar to CDK2.
    Mots-clés : cancer, CDK7, drug discovery, isothermal titration calorimetry, MACO, POLE 1, protein kinases.

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