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2021



  • M. Abdellaoui, A. Millanvois, E. Levernier, C. Ollivier, and L. Fensterbank, “Visible-Light-Mediated Z-Stereoselective Monoalkylation of β,β-Dichlorostyrenes by Photoredox/Nickel Dual Catalysis”, Synlett, Jan. 2021.
    Abstract: <p>Metal-catalyzed alkylation of 1,1-dihalovinyl moiety commonly suffers from both a lack of stereoselectivity and the overreaction leading to the dialkylation product. The methodology described herein features a new pathway to alkylate stereoselectively β,β-dichlorostyryl substrates to provide the <i>Z</i>-trisubstituted olefin only with fair to good yields. This cross-coupling reaction bears on the smooth and photoinduced formation of a C-centered radical that engages in a nickel-catalyzed organometallic cycle to form the key C<sub>sp2</sub>–C<sub>sp3</sub> bond.</p>
    Tags: MACO, POLE 1.
    Attachment Full Text PDF 507.5 kb (source)


  • C. C. Bories, M. Barbazanges, E. Derat, and M. Petit, “Implication of a Silyl Cobalt Dihydride Complex as a Useful Catalyst for the Hydrosilylation of Imines”, ACS Catalysis, vol. 11, no. 22, p. 14262-14273, Nov. 2021.
    Abstract: Here, we describe the formation and use of silyl cobalt (III) dihydride complexes as powerful catalysts for the hydrosilylation of a variety of imines starting from a low-valent well-defined cobalt (I) complex. The reaction is efficient at low catalyst loadings with a diverse range of imines bearing various protecting groups, as well as aliphatic ketimines and quinoline. Kinetics, DFT calculations, NMR spectroscopic studies, deuteration experiments, and X-ray diffraction analyses allowed us to propose a catalytic cycle based on silyl dihydrocobalt (III) complexes performing a hydrocobaltation.
    Tags: MACO, POLE 1.


  • T. Deis, F. Medici, A. Poussard-Schulz, G. Lemière, and L. Fensterbank, “Synthesis and reactivity of an anionic NHC-borane featuring a weakly coordinating silicate anion”, Journal of Organometallic Chemistry, vol. 956, p. 122120, Dec. 2021.
    Abstract: 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.
    Tags: Anionic NHC, DFT calculations, MACO, NHC-borane, Pentacoordinated compounds, POLE 1, Silicon, Spirosilane.


  • S. C. L. Kamerlin, D. J. Allen, B. de Bruin, E. Derat, and H. Urdal, “Journal Open Access and Plan S: Solving Problems or Shifting Burdens?”, Development and Change, vol. n/a, no. n/a, 2021.
    Abstract: This academic thought piece provides an overview of the history of, and current trends in, publishing practices in the scientific fields known to the authors (chemical sciences, social sciences and humanities), as well as a discussion of how open access mandates such as Plan S from cOAlition S will affect these practices. It begins by summarizing the evolution of scientific publishing, in particular how it was shaped by the learned societies, and highlights how important quality assurance and scientific management mechanisms are being challenged by the recent introduction of ever more stringent open access mandates. The authors then discuss the various reactions of the researcher community to the introduction of Plan S, and elucidate a number of concerns: that it will push researchers towards a pay-to-publish system which will inevitably create new divisions between those who can afford to get their research published and those who cannot; that it will disrupt collaboration between researchers on the different sides of cOAlition S funding; and that it will have an impact on academic freedom of research and publishing. The authors analyse the dissemination of, and responses to, an open letter distributed and signed in reaction to the introduction of Plan S, before concluding with some thoughts on the potential for evolution of open access in scientific publishing.
    Tags: MACO, POLE 1.
    Attachment Snapshot 648.7 kb (source)
    Attachment Full Text PDF 275.8 kb (source)


  • G. Lemière, A. Millanvois, C. Ollivier, and L. Fensterbank, “A Parisian Vision of the Chemistry of Hypercoordinated Silicon Derivatives”, The Chemical Record, vol. 21, no. 5, p. 1119-1129, 2021.
    Abstract: Less than ten years of acquaintance with hypercoordinated silicon derivatives in our lab is described in this account. Martin's spirosilane derivatives open new opportunities as ligands and as agents for the activation of small molecules and bis-catecholato silicates have proven to be exquisite radical precursors in photoredox conditions for broad synthetic applications.
    Tags: Lewis acid, MACO, photoredox, POLE 1, radical, silicate, Silicon.


  • A. Lepoetre, S. Ognier, M. Zhang, J. Wengler, S. Al Ayoubi, C. Ollivier, L. Fensterbank, X. Duten, and M. Tatoulian, “Amination of Cyclohexane by Dielectric Barrier Discharge Processing in a Continuous Flow Microreactor: Experimental and Simulation Studies”, Plasma Chemistry and Plasma Processing, vol. 41, no. 1, p. 351-368, 2021.
    Abstract: A miniaturized flow device has been developed to combine microfluidics technology and plasma process. In this microreactor, atmospheric pressure dielectric barrier discharges are generated in a gas in contact with a liquid phase. This study was conducted with plasma generated in ammonia in contact with a flow of liquid cyclohexane. Cyclohexylamine was synthesized with a good selectivity, and the process can be implemented to improve conversion and effectiveness. Numerical simulations confirmed that N­ H2 radicals are generated in the plasma and react with cyclohexyls radicals to achieve the reaction, giving a selectivity of 50% and a total molar conversion of 20% of cyclohexane. The effects of voltage and frequency on the selectivity and the experimental conversion rate were studied and discussed.
    Tags: MACO, POLE 1.


  • T. Martinez, A. Vanitcha, C. Troufflard, N. Vanthuyne, J. Forté, G. Gontard, G. Lemière, V. Mouriès-Mansuy, and L. Fensterbank, “Indolizy Carbene Ligand. Evaluation of Electronic Properties and Applications in Asymmetric Gold(I) Catalysis”, Angewandte Chemie International Edition, vol. 60, no. 36, p. 19879-19888, 2021.
    Abstract: We report herein a new family of carbene ligands based on an indolizine-ylidene (Indolizy) moiety. The corresponding gold(I) complexes are easily obtained from the gold(I)-promoted cyclization of allenylpyridine precursors. Evaluation of the electronic properties by experimental methods and also by DFT calculations confirms strong σ-donating and π-accepting properties of these ligands. Cationization of the gold(I) complexes generates catalytic species that trigger diverse reactions of (poly)unsaturated precursors. When armed with a methylene phosphine oxide moiety on the stereogenic center adjacent to the nitrogen atom, the corresponding bifunctional carbene ligands give rise to highly enantioselective heterocyclizations. DFT calculations brought some rationalization and highlighted the critical roles played by the phosphine oxide group and the tosylate anion in the asymmetric cyclization of γ-allenols.
    Tags: asymmetric catalysis, carbene, DFT, gold, MACO, phosphine oxide, POLE 1.


  • C. Medena, C. Aubert, E. Derat, L. Fensterbank, G. Gontard, O. Khaled, C. Ollivier, N. Vanthuyne, M. Petit, and M. Barbazanges, “Helical Bisphosphinites in Asymmetric Tsuji-Trost Allylation: a Remarkable P:Pd Ratio Effect”, ChemCatChem, vol. 13, no. 21, p. 4543-4548, 2021.
    Abstract: This article discloses a study on a chiral bis-phosphorylated-helical ligand in the palladium-catalyzed Tsuji-Trost allylation. The use of 2,15-bisphosphinite-[6]-helicenes revealed a remarkable ligand effect, in which the (R) and (S) isomeric products can be selectively formed as a direct function of the amount of ligand introduced. Investigation of the organometallic species involved through 31P NMR spectroscopic analysis of a model complex and X-Ray diffraction analysis together with DFT calculations shed light on this phenomenon.
    Tags: chirality, helicene, homogeneous catalysis, MACO, phosphinite, POLE 1, Tsuji-Trost allylation.


  • B. Neil, F. Lucien, L. Fensterbank, and 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.
    Abstract: 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.
    Tags: MACO, POLE 1.

2020



  • A. Cartier, E. Levernier, A. - L. Dhimane, T. Fukuyama, C. Ollivier, I. Ryu, and L. Fensterbank, “Synthesis of Aliphatic Amides through a Photoredox Catalyzed Radical Carbonylation Involving Organosilicates as Alkyl Radical Precursors”, Advanced Synthesis & Catalysis, vol. 362, no. 11, p. 2254-2259, 2020.
    Abstract: Alkyl radicals, from primary to tertiary, formed by photocatalyzed oxidation of organosilicates, are involved efficiently in radical carbonylation with carbon monoxide (CO), in the presence of various amines and CCl4, leading to a variety of amides in moderate to good yields.
    Tags: Carbonylation, MACO, multi-component reaction, photooxidative catalysis, POLE 1, radical/polar, silicates.
    Attachment Full Text PDF 4.8 Mb (source)


  • L. El Khoury, F. Célerse, L. Lagardère, L. - H. Jolly, E. Derat, Z. Hobaika, R. G. Maroun, P. Ren, S. Bouaziz, N. Gresh, and J. - P. Piquemal, “Reconciling NMR Structures of the HIV-1 Nucleocapsid Protein NCp7 Using Extensive Polarizable Force Field Free-Energy Simulations”, Journal of Chemical Theory and Computation, vol. 16, no. 4, p. 2013-2020, Apr. 2020.
    Abstract: Using polarizable (AMOEBA) and nonpolarizable (CHARMM) force fields, we compare the relative free energy stability of two extreme conformations of the HIV-1 nucleocapsid protein NCp7 that had been previously experimentally advocated to prevail in solution. Using accelerated sampling techniques, we show that they differ in stability by no more than 0.75–1.9 kcal/mol depending on the reference protein sequence. While the extended form appears to be the most probable structure, both forms should thus coexist in water explaining the differing NMR findings.
    Tags: MACO, POLE 1.
    Attachment Full Text PDF 1.7 Mb (source)


  • S. H. Kyne, G. Lefèvre, C. Ollivier, M. Petit, V. - A. R. Cladera, and L. Fensterbank, “Iron and cobalt catalysis: new perspectives in synthetic radical chemistry”, Chemical Society Reviews, Oct. 2020.
    Abstract: This review deals with some key synthetic developments based on the use of iron or cobalt complexes to promote radical reactivity which have been devised over the last decades. We have more particularly focused on reactions for which the impact of this chemistry has yielded greener alternatives to existing processes and also on new transformations, notably hydrogen atom transfer (HAT) triggered processes, which can be promoted through the use of metallic complexes. Preliminary synthetic developments based on the use of photoactive iron and cobalt complexes are also covered.
    Tags: MACO, POLE 1.
    Attachment Full Text PDF 16.6 Mb (source)


  • M. Laurans, K. Trinh, K. Dalla Francesca, G. Izzet, S. Alves, E. Derat, V. Humblot, O. Pluchery, D. Vuillaume, S. Lenfant, F. Volatron, and A. Proust, “Covalent Grafting of Polyoxometalate Hybrids onto Flat Silicon/Silicon Oxide: Insights from POMs Layers on Oxides”, ACS Applied Materials & Interfaces, vol. 12, no. 42, p. 48109-48123, Oct. 2020.
    Abstract: Immobilization of polyoxometalates (POMs) onto oxides is relevant to many applications in the fields of catalysis, energy conversion/storage, or molecular electronics. Optimization and understanding the molecule/oxide interface is crucial to rationally improve the performance of the final molecular materials. We herein describe the synthesis and covalent grafting of POM hybrids with remote carboxylic acid functions onto flat Si/SiO2 substrates. Special attention has been paid to the characterization of the molecular layer and to the description of the POM anchoring mode at the oxide interface through the use of various characterization techniques, including ellipsometry, AFM, XPS, and FTIR. Finally, electron transport properties were probed in a vertical junction configuration and energy level diagrams have been drawn and discussed in relation with the POM molecular electronic features inferred from cyclic-voltammetry, UV–visible absorption spectra, and theoretical calculations. The electronic properties of these POM-based molecular junctions are driven by the POM LUMO (d-orbitals) whatever the nature of the tether or the anchoring group.
    Tags: CSOB, E-POM, MACO, POLE 1, POLE 2, POLE 3.
    Attachment Full Text PDF 6.8 Mb (source)


  • E. Levernier, C. Lévêque, E. Derat, L. Fensterbank, and C. Ollivier, “Towards Visible-Light Photocatalytic Reduction of Hypercoordinated Silicon Species”, Helvetica Chimica Acta, vol. 103, no. 1, p. e1900238, 2020.
    Abstract: Nowadays, the quest of new radical precursors based on heteroatom complexes occupies an increasingly prominent position in contemporary research. Herein, we investigated the behavior and the limitations of hexa- or pentacoordinated organochlorosilanes and related pentacoordinated silyliums as new families of complexes for the generation of radicals under photocatalytic reductive conditions. Particularly, treatment of chlorophenylbis[N,S-pyridine-2-thiolato(−)]silicon(IV) or the related silylium derivative with the fac-Ir(ppy)3 (5 mol-%)/NEt3 (1.5 equiv.) system under blue LEDs irradiation generates a thiopyridyl radical which can participate in the formation of a carbon−sulfur bond by reaction with an allylsulfone. Computational studies supported this experimental finding, and particularly by showing that homolytic fragmentation of C−Ts bond is favored over the fragmentation of thiopyridyl radical.
    Tags: allylation, chlorosilane, cyclic voltammetry, C−S bond, hypercoordinated silicon compounds, MACO, photoreduction, POLE 1, radicals, silylium.
    Attachment Full Text PDF 8.3 Mb (source)


  • T. Martinez, I. Alahyen, G. Lemière, V. Mouriès-Mansuy, and L. Fensterbank, “Straightforward Access to 2-Iodoindolizines via Iodine-Mediated Cyclization of 2-Pyridylallenes”, Organic Process Research & Development, vol. 24, no. 5, p. 817-821, May 2020.
    Abstract: A metal-free access to 2-iodo-1,3-disubstituted indolizines has been developed. The proposed synthesis is relatively simple and efficient and involves the iodine-triggered 5-endo-trig cyclization of 2-pyridylallene precursors. While it can be conducted on a gram scale, the preparation of the precursors is straightforward and does not always require intermediate purifications. The obtained 2-iodoindolizines can be further functionalized through cross-coupling reactions.
    Tags: MACO, POLE 1.
    Attachment Full Text PDF 848 kb (source)


  • R. Salles, B. Abécassis, E. Derat, D. Brouri, A. Bernard, Q. Zhang, A. Proust, C. Desmarets, and G. Izzet, “Hierarchical Self-Assembly of Polyoxometalate-Based Organo Palladium(II) Metallomacrocycles via Electrostatic Interactions”, Inorganic Chemistry, vol. 59, no. 4, p. 2458-2463, Feb. 2020.
    Abstract: The design and synthesis of a supramolecular square composed of polyoxometalate-based hybrid donors and ethylenediamine palladium(II) nodes are reported. The structure of the metallomacrocycle scaffold was inferred by diffusion NMR, small-angle X-ray scattering (SAXS), and molecular modeling. The metallomacrocycle scaffold that contains negatively and positively charged subunits can further self-assemble owing to a competition between the solvation energy of the discrete species and intermolecular electrostatic interactions. When the dissociating character of the solvent was lowered or when in the presence of a protic solvent, different types of multiscale organizations (vesicles and pseudo-1D structures) were selectively formed and were characterized by SAXS and transmission electron microscopy.
    Tags: ARC, E-POM, MACO, POLE 1, POLE 2.
    Attachment Full Text PDF 2.1 Mb (source)


  • A. Sodreau, A. Vivien, A. Moisset, C. Salzemann, C. Petit, and M. Petit, “Simpler and Cleaner Synthesis of Variously Capped Cobalt Nanocrystals Applied in the Semihydrogenation of Alkynes”, Inorganic Chemistry, vol. 59, no. 19, p. 13972-13978, Oct. 2020.
    Abstract: Unlike the classical organometallic approach, we report here a synthetic pathway requiring no reducing sources or heating to produce homogeneous hexagonal-close-packed cobalt nanocrystals (Co NCs). Involving a disproportionation process, this simple and fast (6 min) synthesis is performed at room temperature in the presence of ecofriendly fatty alcohols to passivate Co NCs. Through a recycling step, the yield of Co NCs is improved and the waste generation is limited, making this synthetic route cleaner. After an easy exchange of the capping ligands, we applied them as unsupported catalysts in the stereoselective semihydrogenation of alkynes.
    Tags: MACO, POLE 1.
    Attachment Full Text PDF 4.2 Mb (source)


  • C. Tugny, N. del Rio, M. Koohgard, N. Vanthuyne, D. Lesage, K. Bijouard, P. Zhang, J. Meijide Suárez, S. Roland, E. Derat, O. Bistri-Aslanoff, M. Sollogoub, L. Fensterbank, and V. Mouriès-Mansuy, “β-Cyclodextrin–NHC–Gold(I) Complex (β-ICyD)AuCl: A Chiral Nanoreactor for Enantioselective and Substrate-Selective Alkoxycyclization Reactions”, ACS Catalysis, vol. 10, no. 11, p. 5964-5972, Jun. 2020.
    Abstract: NHC-capped β-cyclodextrin (β-ICyD) was used as a ligand for gold-catalyzed alkoxycyclization reactions. The cavity was found to be responsible for a triple selectivity: (i) the asymmetric shape of the cavity of β-ICyD induced highly stereoselective cyclizations, (ii) the shape of the interior favored the formation of a six-membered ring in the absence of a nucleophile, and finally, (iii) the encapsulation of the metal inside the cavity disfavored the addition of sterically hindered alcohols. Highly enantioselective and substrate-selective alkoxycyclizations of enynes are therefore promoted by the cavity-based molecular reactor (β-ICyD)AuCl.
    Tags: CSOB, GOBS, MACO, POLE 1, POLE 3.
    Attachment Full Text PDF 2.2 Mb (source)


  • G. Xu, S. Leloux, P. Zhang, J. M. Suárez, Y. Zhang, E. Derat, M. Ménand, O. Bistri‐Aslanoff, S. Roland, T. Leyssens, O. Riant, and M. Sollogoub, “Capturing the Monomeric (L)CuH in NHC-Capped Cyclodextrin: Cavity-Controlled Chemoselective Hydrosilylation of α,β-Unsaturated Ketones”, Angewandte Chemie International Edition, vol. 59, no. 19, p. 7591-7597, 2020.
    Abstract: The encapsulation of copper inside a cyclodextrin capped with an N-heterocyclic carbene (ICyD) allowed both to catch the elusive monomeric (L)CuH and a cavity-controlled chemoselective copper-catalyzed hydrosilylation of α,β-unsaturated ketones. Remarkably, (α-ICyD)CuCl promoted the 1,2-addition exclusively, while (β-ICyD)CuCl produced the fully reduced product. The chemoselectivity is controlled by the size of the cavity and weak interactions between the substrate and internal C−H bonds of the cyclodextrin.
    Tags: cavities, copper hydride, cyclodextrins, GOBS, hydrosilylation, MACO, N-heterocyclic carbenes, POLE 1, POLE 3, α, β-unsaturated ketones.
    Attachment Full Text PDF 3.2 Mb (source)


  • X. Zhu, G. Xu, L. - M. Chamoreau, Y. Zhang, V. Mouriès‐Mansuy, L. Fensterbank, O. Bistri‐Aslanoff, S. Roland, and M. Sollogoub, “Permethylated NHC-Capped α- and β-Cyclodextrins (ICyDMe) Regioselective and Enantioselective Gold-Catalysis in Pure Water”, Chemistry – A European Journal, vol. 26, no. 68, p. 15901-15909, 2020.
    Abstract: A series of water-soluble encapsulated copper(I), silver(I) or gold(I) complexes based on NHC-capped permethylated cyclodextrins (ICyDMe) were developed and used as catalysts in pure water for hydration, lactonization, hydroarylation and cycloisomerization reactions. ICyDMe ligands gave cavity-based high regioselectivity in hydroarylations, and high enantioselectivities in gold-catalyzed cycloisomerizations reactions giving up to 98 % ee in water. These ICyDMe are therefore useful ligands for selective catalysis in pure water.
    Tags: catalysis, cavity, cyclodextrin, GOBS, MACO, N-heterocyclic carbenes, POLE 1, POLE 3, water.
    Attachment Full Text PDF 1.7 Mb (source)

2019



  • “15 Silicates in Photocatalysis”, in Photocatalysis in Organic Synthesis, 2019th ed., Stuttgart: Thieme Verlag, 2019, p. 427.
    Abstract: Thieme E-Books & E-Journals
    Tags: CHEMBIO, MACO, POLE 1, POLE 3.


  • A. Cartier, E. Levernier, V. Corcé, T. Fukuyama, A. - L. Dhimane, C. Ollivier, I. Ryu, and L. Fensterbank, “Carbonylation of Alkyl Radicals Derived from Organosilicates through Visible-Light Photoredox Catalysis”, Angewandte Chemie International Edition, vol. 58, no. 6, p. 1789-1793, 2019.
    Abstract: Primary, secondary, and tertiary alkyl radicals formed by the photocatalyzed oxidation of organosilicates underwent efficient carbonylation with carbon monoxide (CO) to give a variety of unsymmetrical ketones. This study introduces the possibility of radical carbonylation under a photooxidative regime.
    Tags: carbonylation, CHEMBIO, MACO, photocatalysis, POLE 1, POLE 3, radicals, silicates, three-component reactions.


  • M. Cassé, C. Nisole, H. Dossmann, Y. Gimbert, J. - M. Fourquez, L. Haberkorn, C. Ollivier, and L. Fensterbank, “Trifluoromethyl radical triggered radical cyclization of <italic>N</italic>-benzoyl ynamides leading to isoindolinones”, SCIENCE CHINA Chemistry, vol. 62, no. 11, p. 1542-1546, Oct. 2019.
    Abstract: Under phot

    ocatalytic reductive conditions, trifluoromethyl radical addition onto an ynamide followed by cyclization on a benzoyl moiety produces diverse isoindolinone platforms with good yields. The selectivity of the radical cyclization, <italic>N</italic>-benzoyl vs. <italic>N</italic>-benzyl as radical acceptor and the <italic>E</italic>/<italic>Z</italic> ratio of isomers have been rationalized by modeling.
    Tags: CSOB, MACO, POLE 1, POLE 3.
    Attachment Full Text PDF 1.6 Mb (source)


  • F. Célerse, L. Lagardère, E. Derat, and J. - P. Piquemal, “Massively Parallel Implementation of Steered Molecular Dynamics in Tinker-HP: Comparisons of Polarizable and Non-Polarizable Simulations of Realistic Systems”, Journal of Chemical Theory and Computation, vol. 15, no. 6, p. 3694-3709, Jun. 2019.
    Abstract: Steered molecular dynamic (SMD) is a powerful technique able to accelerate rare event sampling in Molecular Dynamics (MD) simulations by applying an external force to a set of chosen atoms. Despite generating nonequilibrium simulations, SMD remains capable of reconstructing equilibrium properties such as the Potential of Mean Force (PMF). Of course, one would like to use all types of force fields (FF) ranging from classical ones to more advanced polarizable models using point induced dipoles and distributed multipoles such as AMOEBA. To enable such studies, the SMD methodology has been implemented in the framework of the massively parallel Tinker-HP software allowing for both long polarizable and non-polarizable MD simulations of large proteins. To validate this new implementation, we first compared the Tinker-HP SMD results to the literature. Tests have been performed on three different benchmark systems: the M–A deca-alanine (112 atoms), the ubiquitin (9737 atoms), and the CD2CD58 complex (97594 atoms). Non-polarizable (AMBER99, AMBER99SB, CHARMM22/CMAP, and OPLS–AA/L) and polarizable (AMOEBAPRO13 and AMOEBABIO18) force fields have been used. For each one of them, PMFs have been reconstructed and compared in terms of free energy barrier and hydrogen bonding fluctuations behavior over time. Using a SMD velocity of 0.01 Å/ps applied to a set of 20 trajectories, we show that polarizable and non-polarizable force fields do not always agree. As it could be anticipated, strong discrepancies are noticed between polarizable and non-polarizable models when considered in vacuum, whereas results are more comparable when a water environment is added. However, for the largest system, i.e., the CD2CD58 complex, strong differences related to the modeling of a salt bridge are noticed exhibiting some potential issues with classical FFs. Overall, such simulations highlight the importance of the inclusion of polarization effects as PMF free energy barriers computed with AMOEBA always decrease compared to non-polarizable force fields.
    Tags: MACO, POLE 1.
    Attachment Full Text PDF 3.9 Mb (source)


  • X. Frogneux, L. Hippolyte, D. Mercier, D. Portehault, C. Chanéac, C. Sanchez, P. Marcus, F. Ribot, L. Fensterbank, and S. Carenco, “Direct Synthesis of N-Heterocyclic Carbene-Stabilized Copper Nanoparticles from an N-Heterocyclic Carbene–Borane”, Chemistry – A European Journal, vol. 25, no. 49, p. 11481-11485, 2019.
    Abstract: N-Heterocyclic carbene (NHC)-stabilized copper nanoparticles (NPs) were synthesized from an NHC–borane adduct and mesitylcopper(I) under thermal conditions (refluxing toluene for 2.5 h). NPs with a size distribution of 11.6±1.8 nm were obtained. The interaction between Cu NPs and NHC ligands was probed by X-ray photoelectron spectroscopy, which showed covalent binding of the NHC to the surface of the NPs. Mechanistic studies suggested that NHC–borane plays two roles: contributing to the reduction of [CuMes]2 to release Cu0 species and providing NHC ligands to stabilize the copper NPs.
    Tags: carbene ligands, copper, MACO, nanoparticles, POLE 1, radical reactions, reaction mechanisms.
    Attachment Full Text PDF 853.3 kb (source)


  • L. Lempenauer, G. Lemière, and E. Duñach, “Cyclisation Reactions Involving Alkyl Enol Ethers”, Advanced Synthesis & Catalysis, vol. 361, no. 23, p. 5284-5304, 2019.
    Abstract: Enol ethers are a fascinating product class and valuable building blocks with versatile reactivities and synthetic applications. With the emergence of silyl enol ethers, the chemistry of simple alkyl enol ethers has received less attention and targeted reviews of their chemistry are scarce. Especially intramolecular reactions under participation of an enol ether function have never been specifically surveyed. The construction of cyclic scaffolds is arguably one of the most important and challenging tasks of the organic chemist and intramolecular cyclisations represent the most straight-forward tool to achieve this goal. The potential of enol ether-containing substrates to form oxygenated carbo- and heterocycles is obvious. The purpose of this review is to discuss their particular reactivity and to direct the reader's attention to how their unique properties have been harnessed by organic chemists for the construction of rings.
    Tags: catalysis, cyclisations, enol ethers, intramolecular reactions, Lewis acids, MACO, POLE 1.
    Attachment Full Text PDF 1.1 Mb (source)


  • C. Lévêque, E. Levernier, V. Corcé, L. Fensterbank, M. Malacria, and C. Ollivier, “Photoredox Catalysis, an Opportunity for Sustainable Radical Chemistry”, in Advanced Green Chemistry, vol. Volume 6, World Scientific, 2019, p. 49-121.
    Abstract: The following sections are included: List of Abbreviations Introduction The Photoredox Catalysis as an Alternative Nature as a Source of Inspiration Artificial Redox Photocatalysts Photophysical Properties Principle of Photoredox Catalysis Formation of Carbon Centered Radicals Merging Photoredox and Organometallic Catalysis for Cross-Coupling Reactions Context Radical Trapping by Transition Metals Cobalt Nickel Copper Genesis of the Photoredox/Transition Metal Dual Catalysis: Ruthenium and Palladium Towards Photoredox/Transition Metal Dual Catalysis Processes Processes without Radical Formation: Catalysis of Redox Steps Processes with Radical Formation: Catalysis of Downstream Steps Conclusion Acknowledgments References
    Tags: CHEMBIO, MACO, POLE 1, POLE 3.
    Note Note
    <p>doi:10.1142/9789811210587_0003</p>


  • E. Levernier, V. Corcé, L. - M. Rakotoarison, A. Smith, M. Zhang, S. Ognier, M. Tatoulian, C. Ollivier, and L. Fensterbank, “Cross coupling of alkylsilicates with acyl chlorides via photoredox/nickel dual catalysis: a new synthesis method for ketones”, Organic Chemistry Frontiers, vol. 6, no. 9, p. 1378-1382, Apr. 2019.
    Abstract: Photoredox/nickel dual catalysis using easily oxidized bis-catecholato hypercoordinated silicon derivatives as radical sources and acyl chlorides as electrophiles allows a new method of formation of dialkyl and alkyl-aryl ketones as well as dibenzyl ketones which are less easily accessed. Flow chemistry can be used.
    Tags: CHEMBIO, MACO, POLE 1, POLE 3.
    Attachment Version soumise 654.1 kb (source)


  • G. Maestri and E. Derat, “Alkenyl boost for Catellani”, Nature Chemistry, vol. 11, no. 12, p. 1082-1084, Dec. 2019.
    Abstract: The Catellani reaction is a multi-component cascade sequence, catalysed by palladium and norbornene, which typically uses aromatic starting materials. Now, through the use of a modified norbornene co-catalyst, the scope of this reaction has been extended to alkenyl reagents, enabling the preparation of all-carbon tetrasubstituted olefins.
    Tags: MACO, POLE 1.
    Attachment Full Text PDF 736.2 kb (source)


  • C. Medena, F. Calogero, Q. Lemoine, C. Aubert, E. Derat, L. Fensterbank, G. Gontard, O. Khaled, N. Vanthuyne, J. Moussa, C. Ollivier, M. Petit, and M. Barbazanges, “A HELIXOL-Derived Bisphosphinite Ligand: Synthesis and Application in Gold-Catalyzed Enynes Cycloisomerization”, European Journal of Organic Chemistry, vol. 2019, no. 11, p. 2129-2137, 2019.
    Abstract: The synthesis, optical resolution through derivatization, characterization, and utilization of a new helical bis(phosphinite gold) complex derived from HELIXOL are described. By using an efficient cobalt catalyst, neither irradiation nor high catalytic loading was required to access the helicene of interest. The latter was phosphorylated to afford a new chiral ligand that was studied. Especially, treatment with AuCl(SMe2) gives a dinuclear gold complex that was used in cycloisomerization reactions.
    Tags: ARC, Chirality, Enyne Cycloisomerization, Helicene, Homogeneous catalysis, MACO, Phosphinite, POLE 1.
    Attachment Full Text PDF 1.5 Mb (source)


  • F. Medici, J. Maury, G. Lemière, and L. Fensterbank, “Interaction between Spirosilanes and Lewis Bases: from Coordination to Frustration”, Chemistry – A European Journal, vol. 25, no. 40, p. 9438-9442, 2019.
    Abstract: In this work, the interaction between Lewis bases, especially N-heterocyclic carbenes (NHCs), and hindered neutral silicon derivatives featuring high Lewis acidity is described. The formation of normal and abnormal Lewis adducts could be controlled by varying the acidity of the corresponding tetravalent spiro organosilane. Some DFT calculations permitted to gain insight into the thermodynamics of the NHC–spirosilane interaction featuring various NHCs differing in size and σ-donor capacity. Spirosilanes are introduced as new Lewis partners in frustrated Lewis pair (FLP) chemistry and some FLP-type reactivities are presented, in particular the activation of formaldehyde that could occur with both hindered NHCs and phosphines.
    Tags: frustrated Lewis pairs, Lewis acid, MACO, pentavalent silicon, POLE 1, spirosilanes.
    Attachment Full Text PDF 969.8 kb (source)


  • A. Vivien, M. Guillaumont, L. Meziane, C. Salzemann, C. Aubert, S. Halbert, H. Gérard, M. Petit, and C. Petit, “Role of Oleylamine Revisited: An Original Disproportionation Route to Monodispersed Cobalt and Nickel Nanocrystals”, Chemistry of Materials, vol. 31, no. 3, p. 960-968, Feb. 2019.
    Abstract: Herein is highlighted an original disproportionation mechanism for the formation of hexagonal closed packed cobalt nanoparticles starting from low-valent cobalt complexes. By coupling experimental and theoretical studies, we demonstrate that oleylamine promotes the disproportionation of the starting metal complexes and controls the growth of the nanocrystals, in contrast to the role of reducing reagents proposed elsewhere. We also decipher the sensitivity of the synthesis in regard to the nature of the phosphine and of the halogen ligands in the starting cobalt precursors. Understanding of the mechanism allows the development of a less expensive and less toxic synthesis of these nanoparticles by decreasing the amount of oleylamine in alkane solvents. Finally, an extension of this process is presented and allows reaching size- and shape-controlled nanosphere and nanorod nickel nanoparticles.
    Tags: MACO, POLE 1.


  • Z. Xia, V. Corcé, F. Zhao, C. Przybylski, A. Espagne, L. Jullien, T. L. Saux, Y. Gimbert, H. Dossmann, V. Mouriès-Mansuy, C. Ollivier, and L. Fensterbank, “Photosensitized oxidative addition to gold( i ) enables alkynylative cyclization of o -alkylnylphenols with iodoalkynes”, Nature Chemistry, vol. 11, no. 9, p. 797-805, Sep. 2019.
    Abstract: Studies into gold-catalysed cross-coupling reactions have expanded over recent decades; however, oxidative addition to gold(i) complexes remains challenging. Now it has been shown that a dual catalytic transformation involving iridium photosensitization to trigger oxidative addition to organogold intermediates enables C(sp2)–C(sp) cross-coupling reactions that are useful for the alkynylation of benzofurans.
    Tags: CHEMBIO, CSOB, MACO, POLE 1, POLE 3.
    Attachment Full Text PDF 1.8 Mb (source)

2018



  • M. Barbazanges and L. Fensterbank, “The Invention of New Methodologies: An Opportunity for Dating Natural Products”, Synlett, Aug. 2018.
    Abstract: This Account surveys almost two decades of methodological developments and their straightforward applications to the total synthesis of simple natural products. The main directions covered include radical chemistry and cascades, electrophilic catalysis based on coinage metals, and asymmetric synthesis based on bis(sulfoxides) auxiliaries. 1 Introduction 2 Radical Cascades 2.1 N-Cyanamides 2.2 Homolytic Substitution at Sulfur Atom to Give Sultines 3 Electrophilic Catalysis Based on Platinum(II) and Gold(I) Complexes 4 From Alkylydene Bis(sulfoxides) to Chiral Carboxylic Acids 5 Conclusion and Perspectives
    Tags: asymmetric synthesis, bis(sulfoxides), gold catalysis, Key words radical chemistry, MACO, natural products, POLE 1, total synthesis.
    Attachment Full Text PDF 450.4 kb (source)


  • L. Fensterbank, S. Gao, and A. Zakarian, “Themed collection: Synthetic approaches to natural products via catalytic processes”, Organic Chemistry Frontiers, vol. 5, no. 4, p. 529-530, Feb. 2018.
    Abstract: A graphical abstract is available for this content
    Tags: MACO, POLE 1.
    Attachment Full Text PDF 481 kb (source)


  • L. Fensterbank, J. - P. Goddard, and C. Ollivier, “Visible-Light-Mediated Free Radical Synthesis”, in Visible Light Photocatalysis in Organic Chemistry, Wiley-Blackwell, 2018, p. 25-71.
    Abstract: This chapter concentrates on the photocatalytic generation of radical intermediates that have already been encountered in the past and generated through other pathways. It particularly emphasizes how photocatalysis can really improve the reaction conditions and outcomes. Different oxygenated moieties can be introduced by photocatalysis in place of an initial C—H bond. The development of visible-light photoredox catalysis for radical synthesis has demonstrated high efficiency, selectivity, versatility, and functional group tolerance in various transformations, becoming of great interest in cascade processes intramolecular radical steps. One of the most developed cascade sequence is tandem intermolecular radical addition/homolytic aromatic substitution, which first comprises radical addition onto activated double bond followed by cyclization onto arene and rearomatization by subsequent oxidation of the radical adduct. Radical multicomponent processes have emerged as a convenient and flexible strategy to elaborate complex molecular building blocks. Among them, visible-light photoredox catalysis proved to be efficient for promoting radical/cationic multicomponent reactions (MCRS).
    Tags: cationic multicomponent reaction, C—C bond formation, C—X bond formation, MACO, photocatalytic cycle, POLE 1, radical cascade applications, radical intermediates, radical multicomponent reaction, visible-light-mediated free radical synthesis.


  • F. Forato, A. Belhboub, J. Monot, M. Petit, R. Benoit, V. Sarou‐Kanian, F. Fayon, D. Jacquemin, C. Queffelec, and B. Bujoli, “Phosphonate-Mediated Immobilization of Rhodium/Bipyridine Hydrogenation Catalysts”, Chemistry – A European Journal, vol. 24, no. 10, p. 2457-2465, Feb. 2018.
    Abstract: RhL2 complexes of phosphonate-derivatized 2,2′-bipyridine (bpy) ligands L were immobilized on titanium oxide particles generated in situ. Depending on the structure of the bipy ligand—number of tethers (1 or 2) to which the phosphonate end groups are attached and their location on the 2,2′-bipyridine backbone (4,4′-, 5,5′-, or 6,6′-positions)—the resulting supported catalysts showed comparable chemoselectivity but different kinetics for the hydrogenation of 6-methyl-5-hepten-2-one under hydrogen pressure. Characterization of the six supported catalysts suggested that the intrinsic geometry of each of the phosphonate-derivatized 2,2′-bipyridines leads to supported catalysts with different microstructures and different arrangements of the RhL2 species at the surface of the solid, which thereby affect their reactivity.
    Tags: hydrogenation, immobilization, MACO, N ligands, POLE 1, rhodium, supported catalysts.
    Attachment Full Text PDF 1.1 Mb (source)


  • S. H. Kyne, M. Clémancey, G. Blondin, E. Derat, L. Fensterbank, A. Jutand, G. Lefèvre, and C. Ollivier, “Elucidating Dramatic Ligand Effects on SET Processes: Iron Hydride versus Iron Borohydride Catalyzed Reductive Radical Cyclization of Unsaturated Organic Halides”, Organometallics, vol. 37, no. 5, p. 761-771, Mar. 2018.

    Abstract: An iron(II) borohydride complex ([(η1-H3BH)FeCl(NCCH3)4]) is employed as the precatalyst in iron-catalyzed radical cyclizations of unsaturated organic halides in the presence of NaBH4. Mechanistic investigations have established that the ligand bound to the metal center (acetonitrile versus ethylenebis(diphenylphosphine) (dppe)) plays a crucial role in the structure and reactivity of the active anionic iron(I) hydride ([HFeCl(dppe)2]−) and borohydride ([(η1-H3BH)FeCl(NCCH3)4]−) with unsaturated haloacetals. This work provides new insights into iron(I) hydride and borohydride species and their potential implication in single-electron processes.
    Tags: MACO, POLE 1.


  • L. Lempenauer, A. Soupart, E. Duñach, and G. Lemière, “Synthesis of α-oxygenated β,γ-unsaturated ketones by a catalytic rearrangement strategy”, Organic & Biomolecular Chemistry, vol. 16, no. 30, p. 5441-5445, Aug. 2018.
    Abstract: A straightforward two-step entry to α-oxgenated β,γ-unsaturated ketones from readily available α,β-unsaturated ketones is disclosed. It was found that bis(allylic) alcohols undergo a skeletal rearrangement in the presence of 1 mol% of cheap and non-corrosive p-toluenesulfonic acid. Computational studies were conducted to support the mechanism and to rationalise the influence of the catalyst acidity on the product selectivity.
    Tags: MACO, POLE 1.
    Attachment Full Text PDF 807.7 kb (source)


  • F. Medici, G. Gontard, E. Derat, G. Lemière, and L. Fensterbank, “Synthesis of Stable Pentacoordinate Silicon(IV)–NHC Adducts: An Entry to Anionic N-Heterocyclic Carbene Ligands”, Organometallics, vol. 37, no. 4, p. 517-520, Feb. 2018.
    Abstract: This work features the previously undescribed interactions of Martin’s spirosilane with different types of N-heterocyclic carbenes (NHCs). The level of interaction proved to be strongly dependent on the size of the Lewis base and could vary from the formation of isolable classical Lewis adducts to abnormal Lewis adducts, as evidenced by X-ray diffraction structure analyses and NMR studies. It has been found that abnormal adducts could be used as precursors for the synthesis of anionic NHCs bearing a weakly coordinating siliconate component. Complexation of these new types of carbenes with gold(I) and copper(I) has been efficiently accomplished. DFT calculations performed on the siliconate-based anionic NHC ligands revealed a high-lying HOMO and therefore a strong σ-donor character.
    Tags: MACO, POLE 1.


  • V. Mouriès-Mansuy and L. Fensterbank, “Gold-Catalyzed Migration of Propargyl Acetate as an Entry into the Total Synthesis of Natural Products”, Israel Journal of Chemistry, vol. 58, no. 5, p. 586-595, Apr. 2018.
    Abstract: Abstract Gold catalysis has emerged over the last two decades as a protocole of choice for the efficient and selective activation of a variety of organic functional groups. This has served to the total synthesis of natural products at several occasions. In this context, the gold-catalyzed migration (1,2- or 1,3-) of propargyl acetates has been particularly used. This review highlights these different synthetic developments which are presented according to the involved mechanisms.
    Tags: acetate migration, gold catalysis, MACO, organogold intermediate, POLE 1, propargyl acetate, total synthesis.
    Attachment Full Text PDF 4.6 Mb (source)


  • Y. Ren, K. Cheaib, J. Jacquet, H. Vezin, L. Fensterbank, M. Orio, S. Blanchard, and M. Desage‐El Murr, “Copper-Catalyzed Aziridination with Redox-Active Ligands: Molecular Spin Catalysis”, Chemistry – A European Journal, vol. 24, no. 20, p. 5086-5090, Apr. 2018.
    Abstract: Small-molecule catalysts as mimics of biological systems illustrate the chemists’ attempts at emulating the tantalizing abilities displayed by nature's metalloenzymes. Among these innate behaviors, spin multistate reactivity is used by biological systems as it offers thermodynamic leverage towards challenging chemical reactivity but this concept is difficult to translate into the realm of synthetic organometallic catalysis. Here, we report a rare example of molecular spin catalysis involving multistate reactivity in a small-molecule biomimetic copper catalyst applied to aziridination. This behavior is supported by spin state flexibility enabled by the redox-active ligand.
    Tags: aziridination, copper catalysis, E-POM, MACO, multistate reactivity, POLE 1, POLE 2, redox-active ligands, spin catalysis.
    Attachment Full Text PDF 963.4 kb (source)


  • J. Wengler, S. Ognier, M. Zhang, E. Levernier, C. Guyon, C. Ollivier, L. Fensterbank, and M. Tatoulian, “Microfluidic chips for plasma flow chemistry: application to controlled oxidative processes”, Reaction Chemistry & Engineering, Oct. 2018.
    Abstract: The present paper reports the integration of nonthermal plasma into a biphasic gas–liquid microfluidic chip. It evaluates the potential of plasma activation to become a synthetic tool in organic chemistry, operating under mild conditions (room temperature, atmospheric pressure) and without a catalyst. Few preceding works on plasma chemistry involved a liquid phase and none of them was able to handle the high reactivity of plasma to achieve both high conversion rates and selective reactions. We fabricated a glass-polymer microfluidic chip comprising a one metre long serpentine channel, in which a parallel gas–liquid flow was stabilized thanks to a specific step-like cross-sectional shape. Transparent ITO electrodes, deposited on both sides of the chip and linked to an AC high voltage source, produced a dielectric barrier discharge along the channel. We assessed the behaviour of the flow through optical observations and characterized the discharge through electrical measurements and real time intensified-CCD monitoring. We report the successful treatment of liquid cyclohexane with oxygen plasma inside our chip. The GC analysis of the outflowing liquid revealed only a partial oxidation of cyclohexane into a mixture of cyclohexanol and cyclohexanone (industrially known as “KA oil”), and cyclohexyl hydroperoxide, with a total selectivity above 70% and conversion up to 30%. This indicates that alkanes can be activated and functionalized by means of plasma discharges, in a controlled way. In that respect, we claim to have successfully overcome some of the barriers to industrially relevant plasma chemistry. We believe that the combined use of plasma and microfluidic technologies is essential to the development of this new field of research.
    Tags: MACO, POLE 1.

2017



  • M. Desage‐El Murr, L. Fensterbank, and C. Ollivier, “Iron and Single Electron Transfer: All is in the Ligand”, Israel Journal of Chemistry, vol. 57, no. 12, p. 1160-1169, Dec. 2017.
    Abstract: This account describes some advances we have made in the field of iron catalysis. Two types of reactivity have been uncovered. Based on the use of an iron(II) precatalyst in the presence of NaBH4, the first one consists in a SET which can be useful for the reductive dehalogenation of iodide and bromide derivatives. Switching to the non-innocent bis-iminopyridine ligands promotes a previously undescribed Csp2−H activation reaction leading to biaryl derivatives. First clues into the intricate nature of the mechanism were obtained and suggested that the redox-active bis-iminopyridine ligand acts as an electron reservoir. The resulting buildup of electron density triggers the C−H bond breaking. All these findings are discussed in light of the existing literature and perspectives are given.
    Tags: C−H Activation, C−X Activation, Iron Hydride, MACO, Redox Ligand, Single Electron Transfer.
    Attachment Full Text PDF 3.8 Mb (source)


  • T. Driant, F. Nachon, C. Ollivier, P. - Y. Renard, and E. Derat, “On the Influence of the Protonation States of Active Site Residues on AChE Reactivation: A QM/MM Approach”, ChemBioChem, vol. 18, no. 7, p. 666-675, 2017.
    Abstract: Acetylcholinesterase (AChE), an enzyme of the serine hydrolase superfamily, is a mediator of signal transmission at cholinergic synapses by catalyzing acetylcholine cleavage into acetate and choline. This enzyme is vulnerable to covalent inhibition by organophosphate compounds (like VX). Covalent inhibition of AChE does not revert spontaneously. Known reactivator compounds have limited action in restoring catalytic activity. QM/MM simulations of VX-inhibited AChE reactivation by pralidoxime

    (2-PAM), a classical reactivator, were performed. These afforded a broad view of the effect of protonation states of active-site residues, and provide evidence for the role of Glu202, which needs to be protonated for reactivation to occur. In situ deprotonation of 2-PAM for both protonation states of Glu202 showed that His447 is able to deprotonate 2-PAM with the assistance of Glu202. Because the active site of serine hydrolases is highly conserved, this work provides new insights on the interplay between the catalytic triad residues and this glutamate, newly identified as protonatable.
    Tags: acetylcholinesterase, Computational chemistry, MACO, organophosphate, POLE 1, protonation, QM/MM, reactivation.


  • L. Ferrand, Y. Lyu, A. Rivera-Hernández, B. J. Fallon, M. Amatore, C. Aubert, and M. Petit, “Hydroboration and Diboration of Internal Alkynes Catalyzed by a Well-Defined Low-Valent Cobalt Catalyst”, Synthesis, Apr. 2017.
    Abstract: Thieme E-Books & E-Journals
    Tags: MACO, POLE 1.


  • L. Ferrand, Y. Tang, C. Aubert, L. Fensterbank, V. Mouriès-Mansuy, M. Petit, and M. Amatore, “Niobium-Catalyzed Intramolecular Addition of O–H and N–H Bonds to Alkenes: A Tool for Hydrofunctionalization”, Organic Letters, vol. 19, no. 8, p. 2062-2065, 2017.
    Abstract: A convenient, versatile, and easy to handle intramolecular hydrofunctionalization of alkenes (C–O and C–N bonds formation) is reported using a novel niobium-based catalytic system. This atom economic and eco-friendly methodology provides an additional synthetic tool for the straightforward formation of valuable building blocks enabling molecular complexity. Various pyran, furan, pyrrolidine, piperidine, lactone, and lactam derivatives as well as spirocyclic compounds are produced in high yields and selectivities.
    Tags: MACO, POLE 1.


  • S. Guélen, M. Blazejak, L. - M. Chamoreau, A. Huguet, S. Derenne, F. Volatron, V. Mouriès-Mansuy, and L. Fensterbank, “Photochemical studies on bis-sulfide and -sulfone tethered polyenic derivatives”, Organic & Biomolecular Chemistry, vol. 15, no. 19, p. 4180-4190, May 2017.
    Abstract: This study focusses on the [2 + 2]-photocycloaddition of a symmetric polyenic system tethered by an aryl bis-sulfide or sulfone platform. Using direct irradiation or photosensitization, no expected ladderane product was isolated. In most cases, only tricyclic products including a single cyclobutane moiety were formed. Irradiation of bis-acrylic precursors in water with encapsulation by a host (cyclodextrin or cucurbituril) provided a stereoselective access to valuable cyclobutyl adducts.
    Tags: MACO, POLE 1.
    Attachment Full Text PDF 1002.8 kb (source)


  • J. Jacquet, K. Cheaib, Y. Ren, H. Vezin, M. Orio, S. Blanchard, L. Fensterbank, and M. Desage‐El Murr, “Circumventing Intrinsic Metal Reactivity: Radical Generation with Redox-Active Ligands”, Chemistry – A European Journal, vol. 23, no. 60, p. 15030-15034, Oct. 2017.
    Abstract: Nickel complexes have gained sustained attention as efficient catalysts in cross-coupling reactions and co-catalysts in dual systems due to their ability to react with radical species. Central to this reactivity is nickel's propensity to shuttle through several accessible redox states from Ni0 to NiIV. Here, we report the catalytic generation of trifluoromethyl radicals from a nickel complex bearing redox-active iminosemiquinone ligands. This unprecedented reactivity is enabled through ligand-based oxidation performing electron transfer to an electrophilic CF3+ source while the nickel oxidation state is preserved. Additionally, extension of this reactivity to a copper complex bearing a single redox equivalent is reported, thus providing a unified reactivity scheme. These results open new pathways in radical chemistry with redox-active ligands.
    Tags: CF3. radicals, E-POM, MACO, nickel, POLE 2, redox-active ligand, single electron transfer.
    Attachment Full Text PDF 790 kb (source)


  • C. Lévêque, V. Corcé, L. Chenneberg, C. Ollivier, and L. Fensterbank, “Photoredox/Nickel Dual Catalysis for the C(sp3)–C(sp3) Cross-Coupling of Alkylsilicates with Alkyl Halides”, European Journal of Organic Chemistry, vol. 2017, no. 15, p. 2118-2121, 2017.
    Abstract: Alkylsilicates were engaged under photoredox/nickel dual catalysis conditions with alkyl halides for the first time. The C(sp3)–C(sp3) cross-coupling products were obtained in moderate yields and were accompanied by the homocoupling products of the alkyl halide derivatives. These promising findings are strongly suggestive of the high synthetic potential of the dual catalytic approach for the forging of alkyl carbon–carbon bonds.
    Tags: cross-coupling, C–C coupling, MACO, Nickel, photoredox catalysis, POLE 1, radical reactions.
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