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  • J. M. Cameron, G. Guillemot, T. Galambos, S. S. Amin, E. Hampson, K. Mall Haidaraly, G. N. Newton, et G. Izzet, « Supramolecular assemblies of organo-functionalised hybrid polyoxometalates: from functional building blocks to hierarchical nanomaterials », Chemical Society Reviews, vol. 51, nᵒ 1, p. 293-328, 2022.
    Résumé : Organic–inorganic hybrid polyoxometalates are versatile building blocks for the self-assembly of functional supramolecular materials. , This review provides a comprehensive overview of recent advances in the supramolecular organisation and hierarchical self-assembly of organo-functionalised hybrid polyoxometalates (hereafter referred to as hybrid POMs), and their emerging role as multi-functional building blocks in the construction of new nanomaterials. Polyoxometalates have long been studied as a fascinating outgrowth of traditional metal-oxide chemistry, where the unusual position they occupy between individual metal oxoanions and solid-state bulk oxides imbues them with a range of attractive properties ( e.g. solubility, high structural modularity and tuneable properties/reactivity). Specifically, the capacity for POMs to be covalently coupled to an effectively limitless range of organic moieties has opened exciting new avenues in their rational design, while the combination of distinct organic and inorganic components facilitates the formation of complex molecular architectures and the emergence of new, unique functionalities. Here, we present a detailed discussion of the design opportunities afforded by hybrid POMs, where fine control over their size, topology and their covalent and non-covalent interactions with a range of other species and/or substrates makes them ideal building blocks in the assembly of a broad range of supramolecular hybrid nanomaterials. We review both direct self-assembly approaches (encompassing both solution and solid-state approaches) and the non-covalent interactions of hybrid POMs with a range of suitable substrates (including cavitands, carbon nanotubes and biological systems), while giving key consideration to the underlying driving forces in each case. Ultimately, this review aims to demonstrate the enormous potential that the rational assembly of hybrid POM clusters shows for the development of next-generation nanomaterials with applications in areas as diverse as catalysis, energy-storage and molecular biology, while providing our perspective on where the next major developments in the field may emerge.

  • S. Curpanen, G. Poli, A. Perez-Luna, et J. Oble, « C3−H Silylation of Furfurylimines: Direct Access to a Novel Biobased Versatile Synthetic Platform Derived from Furfural », Asian Journal of Organic Chemistry, vol. 11, nᵒ 7, p. e202200199, 2022.
    Résumé : Herein we report directed iridium-catalyzed C3−H silylation of furfuryl imines, which grants access to versatile synthetic platforms. This transformation was developed on furfuryl derivatives, using imines as directing groups, and trialkylsilanes or bis(trimethylsilyl)methylsilane as silylating agents, in the presence of a hydride scavenger. Subsequently, fluoride-mediated activation strategies were applied to the C3−SiMe(OSiMe3)2 furfural derivatives to achieve a wide range of transformations of the C3−Si bond. Arylation, alkenylation, alkynylation, allylation and alkylation, as well as halogenation and trifluoromethylation were achieved in modest to high yields. A variety of high value-added products were thus easily obtained from the same common C3-silylated furfural-based platform.
    Mots-clés : Biomass, Fluoride, Furfural, Iridium, POLE 1, ROCS, Silicon.

  • S. Curpanen, P. Reichert, G. Lupidi, G. Poli, J. Oble, et A. Perez-Luna, « Modular synthesis of 2-furyl carbinols from 3-benzyldimethylsilylfurfural platforms relying on oxygen-assisted C–Si bond functionalization », Beilstein Journal of Organic Chemistry, vol. 18, nᵒ 1, p. 1256-1263, sept. 2022.
    Résumé : Beilstein Journal of Organic Chemistry
    Mots-clés : POLE 1, ROCS.

  • P. Idlas, A. Ladaycia, F. Némati, E. Lepeltier, P. Pigeon, G. Jaouen, D. Decaudin, et C. Passirani, « Ferrocifen stealth LNCs and conventional chemotherapy: a promising combination against multidrug-resistant ovarian adenocarcinoma », International Journal of Pharmaceutics, p. 122164, sept. 2022.
    Résumé : Ovarian cancer is one of the deadliest epithelial malignancies in women, owing to the multidrug resistance that restricts the success of conventional chemotherapy, carboplatin and paclitaxel. High grade serous ovarian carcinoma can be classified into two subtypes, the chemosensitive High OXPHOS and the Low OXPHOS tumour, less sensitive to chemotherapy. This difference of treatment efficacy could be explained by the redox status of these tumours, High OXPHOS exhibiting a chronic oxidative stress and an accumulation of reactive oxygen species. Ferrocifens, bio-organometallic compounds, are believed to be ROS producers with a good cytotoxicity on ovarian cancer cell lines. The aim of this study was to evaluate the in vivo efficacy of ferrocifen stealth lipid nanocapsules on High and Low OXPHOS ovarian Patient-Derived Xenograft models, alone or in combination to standard chemotherapy. Accordingly, two ferrocifens, P53 and P722, were encapsulated in stealth LNCs. The treatment by stealth P722-LNCs in combination with standard chemotherapy induced, with a concentration eight time lower than in stealth P53-LNCs, similar tumour reduction on a Low OXPHOS model, allowing us to conclude that P722 could be a leading ferrocifen to treat ovarian cancer. This combination of treatments may represent a promising synergistic approach to treat resistant ovarian adenocarcinoma.
    Mots-clés : CHEMBIO, Multidrug resistance, Nanoparticle, Organometallic compound, Ovarian cancer, Patient-Derived Xenograft model, POLE 3, ROS producer molecule.

  • D. Illuminati, A. Fantinati, T. De Ventura, D. Perrone, C. Sturaro, V. Albanese, E. Marzola, V. Cristofori, J. Oble, G. Poli, et C. Trapella, « Synthesis of 2,6-Dimethyltyrosine-Like Amino Acids through Pinacolinamide-Enabled C–H Dimethylation of 4-Dibenzylamino Phenylalanine », The Journal of Organic Chemistry, vol. 87, nᵒ 5, p. 2580-2589, mars 2022.
    Résumé : The synthesis of a small library of NH-Boc- or NH-Fmoc-protected l-phenylalanines carrying methyl groups at positions 2 and 6 and diverse functionalities at position 4 has been achieved. The approach, which took advantage of a Pd-catalyzed directed C–H dimethylation of picolinamide derivatives, allowed the electronic and steric properties of the resulting amino acid derivatives to be altered by appending a variety of electron-withdrawing, electron-donating, or bulky groups.
    Mots-clés : POLE 1, ROCS.

  • L. K/Bidi, A. Desjonquères, G. Izzet, et G. Guillemot, « H<sub>2</sub> Evolution at a Reduced Hybrid Polyoxometalate and Its Vanadium-Oxo Derivative Used as Molecular Models for Reducible Metal Oxides », Inorganic Chemistry, p. acs.inorgchem.2c01741, juill. 2022.

  • S. Kassamba, A. Perez-Luna, F. Ferreira, et M. Durandetti, « Modular access to substituted germoles by intramolecular germylzincation », Chemical Communications, vol. 58, nᵒ 24, p. 3901-3904, mars 2022.
    Résumé : Intramolecular alkyne germylzincation giving access to a wide range of germoles is achieved from triarylhydrogermanes in the presence of diethylzinc and AIBN as radical initiator. The reaction proceeds through activation of the Ge–H bond, leading to a heteroarylzinc intermediate after cyclisation, which can then be involved in a post-functionalisation reaction. Our results show that only 5-endo-dig cyclizations occur, with benzogermoles being exclusively obtained.
    Mots-clés : POLE 1, ROCS.

  • M. Laurans, M. Mattera, R. Salles, L. K’Bidi, P. Gouzerh, S. Renaudineau, F. Volatron, G. Guillemot, S. Blanchard, G. Izzet, A. Solé-Daura, J. M. Poblet, et A. Proust, « When Identification of the Reduction Sites in Mixed Molybdenum/Tungsten Keggin-Type Polyoxometalate Hybrids Turns Out Tricky », Inorganic Chemistry, vol. 61, nᵒ 20, p. 7700-7709, mai 2022.

  • Y. Mazouzi, F. Sallem, F. Farina, A. Loiseau, N. R. Tartaglia, M. Fontaine, A. Parikh, M. Salmain, C. Neri, et S. Boujday, « Biosensing Extracellular Vesicle Subpopulations in Neurodegenerative Disease Conditions », ACS Sensors, vol. 7, nᵒ 6, p. 1657-1665, juin 2022.
    Résumé : Extracellular vesicles (EVs) are secreted nanoparticles that are involved in intercellular communication and that modulate a wide range of biological processes in normal and disease conditions. However, EVs are highly heterogeneous in terms of origin in the cell, size, and density. As a result, complex protocols are required to identify and characterize specific EV subpopulations, limiting biomedical applications, notably in diagnostics. Here, we show that combining quartz crystal microbalance with dissipation (QCM-D) and nanoplasmonic sensing (NPS) provides a facile method to track the viscoelastic properties of small EVs. We applied this multisensing strategy to analyze small EVs isolated by differential ultracentrifugation from knock-in mouse striatal cells expressing either a mutated allele or wild-type allele of huntingtin (Htt), the Huntington’s disease gene. Our results validate the sensing strategy coupling QCM-D and NPS and suggest that the mass and viscoelastic dissipation of EVs can serve as potent biomarkers for sensing the intercellular changes associated with the neurodegenerative condition.
    Mots-clés : CHEMBIO, POLE 3.

  • A. Mori, S. Curpanen, C. Pezzetta, A. Perez-Luna, G. Poli, et J. Oble, « C−H Activation Based Functionalization of Furfural Derivatives », European Journal of Organic Chemistry, vol. n/a, nᵒ n/a, p. e202200727, 2022.
    Résumé : Furfural and related compounds are building blocks of industrial interest, obtained from raw biomass. Their use as precursors of basic and fine chemicals has gained increasing attention as a green alternative to petroleum-derived compounds. Several works have reported the functionalization of furfurals to obtain a wider range of chemicals, opening up new synthetic possibilities and applications, ranging from biofuels to pharmaceuticals. Among these works, processes based on C−H activation are the most attractive ones for their atom economy and the possibility to use non-activated substrates. This minireview summarizes the reported methods of direct C−H functionalization of furfurals without prior modification of the redox state of the aldehyde function. In particular, the transition metal catalyzed functionalization of each bond of the heteroaromatic nucleus of these molecules is systematically discussed, as well as examples of C−H transformations of the aldehyde function.
    Mots-clés : Biomass, Catalysis, C−H Activation, Furfural, POLE 1, ROCS, Transition metal.

  • F. Najlaoui, B. Busser, G. S. Taïwe, P. Pigeon, N. Sturm, D. Giovannini, N. Marrakchi, A. Rhouma, G. Jaouen, S. Gibaud, et M. De Waard, « Succinimido–Ferrocidiphenol Complexed with Cyclodextrins Inhibits Glioblastoma Tumor Growth In Vitro and In Vivo without Noticeable Adverse Toxicity », Molecules, vol. 27, nᵒ 14, p. 4651, janv. 2022.
    Résumé : SuccFerr (N-[4-ferrocenyl,5-5-bis (4-hydroxyphenyl)-pent-4-enyl]-succinimide) has remarkable antiproliferative effects in vitro, attributed to the formation of a stabilized quinone methide. The present article reports in vivo results for a possible preclinical study. SuccFerr is lipophilic and insoluble in water, so the development of a formulation to obviate this inconvenience was necessary. This was achieved by complexation with randomly methylated cyclodextrins (RAMEßCDs). This supramolecular water-soluble system allowed the in vivo experiments below to proceed. Application of SuccFerr on the glioblastoma cancer cell line U87 indicates that it affects the cellular cycle by inducing a blockade at G0/G1 phase, linked to apoptosis, and another one at the S phase, associated with senescence. Using healthy Fischer rats, we show that both intravenous and subcutaneous SuccFerr: RAMEßCD administration at 5 mg/kg lacks toxic effects on several organs. To reach lethality, doses higher than 200 mg/kg need to be administered. These results prompted us to perform an ectopic in vivo study at 1 mg/kg i.v. ferrocidiphenol SuccFerr using F98 cells xenografted in rats. Halting of cancer progression was observed after six days of injection, associated with an immunological defense response linked to the active principle. These results demonstrate that the properties of the selected ferrocidiphenol SuccFerr transfer successfully to in vivo conditions, leading to interesting therapeutic perspectives based on this chemistry.
    Mots-clés : anticancer drug, CHEMBIO, cyclodextrin, ferrocenyl tamoxifen derivatives, glioblastoma, POLE 3.

  • M. Nicolas, B. Beito, M. Oliveira, M. Tudela Martins, B. Gallas, M. Salmain, S. Boujday, et V. Humblot, « Strategies for Antimicrobial Peptides Immobilization on Surfaces to Prevent Biofilm Growth on Biomedical Devices », Antibiotics, vol. 11, nᵒ 1, p. 13, janv. 2022.
    Résumé : Nosocomial and medical device-induced biofilm infections affect millions of lives and urgently require innovative preventive approaches. These pathologies have led to the development of numerous antimicrobial strategies, an emergent topic involving both natural and synthetic routes, among which some are currently under testing for clinical approval and use. Antimicrobial peptides (AMPs) are ideal candidates for this fight. Therefore, the strategies involving surface functionalization with AMPs to prevent bacterial attachment/biofilms formation have experienced a tremendous development over the last decade. In this review, we describe the different mechanisms of action by which AMPs prevent bacterial adhesion and/or biofilm formation to better address their potential as anti-infective agents. We additionally analyze AMP immobilization techniques on a variety of materials, with a focus on biomedical applications. Furthermore, we summarize the advances made to date regarding the immobilization strategies of AMPs on various surfaces and their ability to prevent the adhesion of various microorganisms. Progress toward the clinical approval of AMPs in antibiotherapy is also reviewed.
    Mots-clés : AMP, antimicrobial, biofilms, biofunctionalization, CHEMBIO, immobilization, peptide, POLE 3.

  • P. Pigeon, M. Gaschard, M. Othman, M. Salmain, et G. Jaouen, « α-Hydroxylactams as Efficient Entries to Diversely Functionalized Ferrociphenols: Synthesis and Antiproliferative Activity Studies », Molecules, vol. 27, nᵒ 14, p. 4549, janv. 2022.
    Résumé : The [ferrocene-ene-phenol] motif has been identified as the pharmacophore responsible for the anticancer activity of the family of ferrocene-based molecules coined ferrocifens, owing to its unique redox properties. The addition of imide entities to the historical ferrociphenol scaffold tremendously enhanced the cytotoxic activity of a large panel of cancer cell cultures and preliminary studies showed that the reduction of one of the carbonyl groups of the imide groups to the corresponding α-hydroxylactams only slightly affected the antiproliferative activity. As a continuation to these studies, we took advantage of the facile conversion of α-hydroxylactams to highly electrophilic N-acyliminium ions to graft various substituents to the imide motif of phthalimido ferrocidiphenol. Cell viability studies showed that the newly synthesized compounds showed diverse cytotoxic activities on two breast cancer cell lines, while only one compound was significantly less active on the non-tumorigenic cell line hTERT-RPE1.
    Mots-clés : <i>N</i>-acyliminium ion, anticancer activity, CHEMBIO, ferrocene, ferrocifen, hydroxylactam, POLE 3.

  • R. Sala, G. Kiala, L. F. Veiros, G. Broggini, G. Poli, et J. Oble, « Redox-Neutral Ru(0)-Catalyzed Alkenylation of 2-Carboxaldimine-heterocyclopentadienes », The Journal of Organic Chemistry, vol. 87, nᵒ 7, p. 4640-4648, avr. 2022.
    Résumé : A new Ru3(CO)12-catalyzed directed alkenylation of 2-carboxaldimine-heterocyclopentadienes has been accomplished. This process allows coupling of furan, pyrrole, indole, and thiophene 2-carboxaldimines with electron-poor alkenes such as acrylates, vinylsulfones, and styrenes. This regio- and chemoselective oxidative C–H coupling does not require the presence of an additional sacrificial oxidant. Density functional theory calculations allowed us to propose a mechanism and unveiled the nature of the H2 acceptor.
    Mots-clés : POLE 1, ROCS.

  • J. Sanz Garcia, M. Gaschard, I. Navizet, M. Sahihi, S. Top, Y. Wang, P. Pigeon, A. Vessières, M. Salmain, et G. Jaouen, « Inhibition of cathepsin B by ferrocenyl indenes highlights a new pharmacological facet of ferrocifens », European Journal of Inorganic Chemistry, vol. 2022, nᵒ 9, janv. 2022.
    Résumé : The family of ferrocifens initially built up from the anti-estrogen tamoxifen shows a broad antitumor activity both  in vitro  and  in vivo . Their mechanism of action relies on the presence of the redox motif [ferrocene-ene-phenol] that, under oxidative conditions, generates reactive oxygen species (ROS) and affords electrophilic quinone methides (QMs) having the ability to alkylate biological nucleophiles and in turn elicit a strong antiproliferative activity. In this context, the cysteine protease cathepsin B was initially presumed to be a target for ferrocenyl QMs.  In vitro  enzymatic assays ruled out this hypothesis but unexpectedly revealed that other ferrocifen metabolites, i.e. ferrocenyl indenes, acted as moderate inhibitors of cathepsin B. These experimental results were nicely confirmed by molecular docking calculations, that showed that the monophenol ferrocenyl indene and to a lower extent the diphenol interacted with the active site of cathepsin B, making it an unanticipated target of ferrocifens.
    Mots-clés : antitumor agent, bioorganometallic chemistry, CHEMBIO, computational chemistry, cysteine protease, docking, POLE 3.
    Note Note

  • Y. Wang, P. Pigeon, W. Li, J. Yan, P. M. Dansette, M. Othman, M. J. McGlinchey, et G. Jaouen, « Diversity-oriented synthesis and bioactivity evaluation of N-substituted ferrocifen compounds as novel antiproliferative agents against TNBC cancer cells », European Journal of Medicinal Chemistry, p. 114202, mars 2022.
    Résumé : Ferrociphenols are characterized by the presence of a biologically active redox motif [ferrocenyl-ene-p-phenol], and are known to exhibit anticancer properties. Recent studies have identified a new series of ferrociphenols that bear an imido-type heterocycle at the terminus of a short alkyl chain, and which showed very strong antiproliferativity against multiple types of cancer cells. This work describes the syntheses and an SAR study of ferrociphenols bearing a diversity-based range of nitrogen-containing substituents on the alkyl chain. Preliminary oxidative metabolism experiments and ROS-related bioactivity measurements were also carried out to probe the origin of the cytotoxicity of the imido-ferrociphenols. Furthermore, an interesting dimerization phenomenon was observed in the X-ray crystal structure of the 2,3-naphthalenedicarboximidopropyl-ferrocidiphenol, 21, which may be a factor in decreasing its rate of oxidation to form the corresponding quinone methide, 21-QM, thereby affecting its antitumor activity. These results suggest that both the formation rate and the stability of QMs could affect the antiproliferative activity of their ferrociphenol precursors.
    Mots-clés : Anticancer agents, Bioorganometallic chemistry, CHEMBIO, Ferrocene, Imides, POLE 3, Quinones.


  • M. Abdellaoui, A. Millanvois, E. Levernier, C. Ollivier, et L. Fensterbank, « Visible-Light-Mediated Z-Stereoselective Monoalkylation of β,β-Dichlorostyrenes by Photoredox/Nickel Dual Catalysis », Synlett, janv. 2021.
    Résumé : <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>
    Mots-clés : MACO, POLE 1.
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  • M. Balas, S. Beaudoin, A. Proust, F. Launay, et R. Villanneau, « Advantages of Covalent Immobilization of Metal-Salophen on Amino-Functionalized Mesoporous Silica in Terms of Recycling and Catalytic Activity for CO2 Cycloaddition onto Epoxides », European Journal of Inorganic Chemistry, vol. 2021, nᵒ 16, p. 1581-1591, 2021.
    Résumé : NiII and MnIII Schiff base complexes (Salophen-Ni and Salophen-MnCl) bearing a pending carboxylic group were prepared and characterized. Both complexes were grafted onto a mesoporous amino-functionalized SBA-15 silica, by formation of an amide function between the propylamine groups of the support and the carboxylic acid functions of the salophen ligand (corresponding respective to 1.30 wt.% of Ni and 1.06 wt.% of Mn). The co-catalytic behaviour of the free and grafted complexes was then evaluated in the CO2 cycloaddition reaction onto styrene oxide, using tetra-butylammonium bromide (n−Bu4NBr) as the main catalyst. In homogeneous conditions, the MnIII Schiff base complex and the NiII one, to a lesser extent, behave as efficient co-catalysts for this reaction (styrene conversion of 100 % and 65 % respectively after 3 h at 120 °C, under 15 bars of CO2). Upon immobilization at the surface of the amino-functionalized SBA-15, we showed that the co-catalytic activity of the less efficient one, i. e. Ni2+ salophen complex, could be enhanced (reaching a full conversion after 7 h), hence highlighting a potential synergistic effect between the unused amine functions of the support and the Ni2+ salophen co-catalyst. Both salophen complexes were successfully re-used in homogeneous conditions or after their immobilization without any appreciable loss of activity. This work is only a first step towards a completely heterogeneous catalytic system, in which the tetraalkylammonium halide catalyst and the metal-salophen co-catalyst will both be covalently anchored on the same support.
    Mots-clés : CO2 valorization, Cyloaddition, E-POM, Hybrid catalysts, Mesoporous materials, POLE 2, Salen derivatives.
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  • M. Balas, L. K/Bidi, F. Launay, et R. Villanneau, « Chromium-Salophen as a Soluble or Silica-Supported Co-Catalyst for the Fixation of CO2 Onto Styrene Oxide at Low Temperatures », Frontiers in Chemistry, vol. 9, p. 765108, oct. 2021.
    Résumé : Addition of a soluble or a supported Cr III -salophen complex as a co-catalyst greatly enhances the catalytic activity of Bu 4 NBr for the formation of styrene carbonate from styrene epoxide and CO 2 . Their combination with a very low co-catalyst:Bu 4 NBr:styrene oxide molar ratio = 1:2:112 (corresponding to 0.9 mol% of Cr III co-catalyst) led to an almost complete conversion of styrene oxide after 7 h at 80°C under an initial pressure of CO 2 of 11 bar and to a selectivity in styrene carbonate of 100%. The covalent heterogenization of the complex was achieved through the formation of an amide bond with a functionalized {NH 2 }-SBA-15 silica support. In both conditions, the use of these Cr III catalysts allowed excellent conversion of styrene already at 50°C (69 and 47% after 24 h, respectively, in homogeneous and heterogeneous conditions). Comparison with our previous work using other metal cations from the transition metals particularly highlights the preponderant effect of the nature of the metal cation as a co-catalyst in this reaction, that may be linked to its calculated binding energy to the epoxides. Both co-catalysts were successfully reused four times without any appreciable loss of performance.
    Mots-clés : E-POM, POLE 2.

  • E. Benazzi, J. Karlsson, Y. Ben M'Barek, P. Chabera, S. Blanchard, S. Alves, A. Proust, T. Pullerits, G. Izzet, et E. A. Gibson, « Acid-triggering of light-induced charge-separation in hybrid organic/inorganic molecular photoactive dyads for harnessing solar energy », Inorganic Chemistry Frontiers, vol. 8, nᵒ 6, p. 1610-1618, 2021.
    Résumé : H + modulated charge-transfer in photoexcited covalently linked W and Mo Keggin-bodipy conjugates is demonstrated using transient absorption spectroscopy and photoluminescence. Adding acid switches on (W) or accelerates (Mo) charge separation. , H + modulated charge-transfer in photoexcited covalent polyoxometalate-bodipy conjugates is described. The hybrid organic/inorganic molecular photoactive dyads are based on Keggin-type polyoxometalates (POMs, where K M = [PM 11 O 39 ] and M = Mo or W) covalently grafted via an organotin linker to a bodipy (BOD) photosensitizer. The relative potentials of the photosensitizer and POM are aligned such that light-induced electron transfer from BOD to POM is permitted for the polyoxomolybdate KMoSn[BOD] but not effective for the polyoxotungstate analogue KWSn[BOD] . In both cases, the addition of acid shifts the redox potential of the POM only, to increase the driving force for electron transfer. This leads to charge-separation being switched on for KWSn[BOD] in the presence of acid. The addition of acid to KMoSn[BOD] accelerates charge-separation by an order of magnitude (from 2 ns to 200 ps) and is accompanied by a deceleration of charge recombination, leading to a charge-separated state lifetime of up to 1.3 μs. This behaviour is consistent with proton coupled electron transfer, which has previously been observed electrochemically for POMs, but this study shows, for the first time, the impact of protonation on photoinduced electron transfer.
    Mots-clés : CSOB, E-POM, POLE 2, POLE 3.

  • A. Benchohra, Y. Li, L. - M. Chamoreau, B. Baptiste, E. Elkaïm, N. Guillou, D. Kreher, et R. Lescouëzec, « The Atypical Hysteresis of [Fe(C6F5Tp)2]: Overlay of Spin-Crossovers and Symmetry-Breaking Phase Transition », Angewandte Chemie, vol. 133, nᵒ 16, p. 8885-8889, 2021.
    Résumé : The [FeII(C6F5Tp)2] spin-crossover complex is an atypical molecular switch, which can be converted upon annealing between two archetypal spin-crossover behaviours: from an extremely gradual spin-crossover to a broad hysteretic spin-transition (of ca. 65 K). The hysteresis shows an uncommon “rounded shape” that is reproducible upon cycling temperature. In depth structural studies reveal a first crystal phase transition, which occurs upon melting and recrystallizing at high temperature. This first irreversible transition is associated with a radical change in the crystal packing. More importantly, the “rounded and broad” hysteretic transition is shown to occur in a non-cooperative SCO system and is associated with the occurrence of a symmetry-breaking phase transition that appears when roughly ca. 50 % of the SCO complexes are switched.
    Mots-clés : ERMMES, POLE 2.

  • C. C. Bories, M. Barbazanges, E. Derat, et 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.
    Résumé : 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.
    Mots-clés : MACO, POLE 1.

  • S. Boujday et M. Salmain, « Nanoparticules d’or pour les biocapteurs : lecture optique de la reconnaissance moléculaire », Photoniques, nᵒ 106, p. 39-43, janv. 2021.
    Résumé : Les propriétés extraordinaires des nanoparticules d’or et/ou d’argent en ont fait des objets courtisés par les scientifiques toutes disciplines confondues. L’intensité de leur couleur ainsi que leur grande sensibilité optique au milieu environnant en font de puissants transducteurs pour les biocapteurs ; que ce soit grâce à des spectrophotomètres ou simplement par observation à l’oeil nu. Elles assurent la lecture de la reconnaissance moléculaire via des scénarios variés alliant simplicité et faible coût.
    Mots-clés : CHEMBIO, POLE 3.

  • F. Carlet, G. Bertarini, G. Broggini, A. Pradal, et G. Poli, « Oxoammonium-Mediated Allylsilane–Ether Coupling Reaction », European Journal of Organic Chemistry, vol. 2021, nᵒ 15, p. 2162-2168, 2021.
    Résumé : A new C(sp3)−H functionalization reaction consisting of the oxidative α-allylation of allyl- and benzyl- methyl ethers has been developed. The C−C coupling could be carried out under mild conditions thanks to the use of cheap and green oxoammonium salts. The scope of the reaction was studied over 27 examples, considering the nature of the substituents on the two coupling partners.
    Mots-clés : Allylation, Benzyl ethers, C(sp3)−H functionalization, Cinnamyl ethers, Oxoammonium, ROCS.

  • L. Chang, N. Fischer-Durand, G. Gontard, B. Bertrand, S. Thorimbert, et L. Dechoux, « A solvent-free, catalyst-free formal [3+3] cycloaddition dearomatization strategy: towards new fluorophores for biomolecules labelling », ChemSusChem, vol. n/a, nᵒ n/a, 2021.
    Résumé : A general, sustainable dearomatization reaction for nitrogen-containing heterocycles was developed. Under solvent free conditions and without catalyst, the biorenewable methyl coumalate ( MC ) reacts as an efficient C3 partner to convert eleven types of basic aromatic rings into their pyrido[1,2-a] fused derivatives in good to excellent yields. The fluorescence properties of some of the products were harnessed to conjugate fluorescent tags to BSA and immunoglobulin G.
    Mots-clés : CHEMBIO, dearomatization reaction, fluorescent probes, methyl coumalate, Michael addition, Nitrogen heterocycles, POLE 3.
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  • F. Chemla et A. Perez-Luna, « 2.5 Radical–Polar Crossover Reactions », in Free Radicals: Fundamentals and Applications in Organic Synthesis 2, 2021ᵉʳ éd., Thieme Verlag, 2021.
    Résumé : Radical–polar crossover reactions, that is, single-electron redox events allowing for the interconversion between radical and ionic intermediates, make it possible to connect radical and polar processes in the same synthetic transformation. Such a combination is the basis of much original synthetic methodology, which is particularly useful in the context of domino, tandem, or multicomponent reactions. This chapter comprehensively covers the field of radical–polar crossover reactions, with a primary emphasis on transformations wherein both the radical and polar processes provide synthetic elaboration.
    Mots-clés : Organic Chemistry, POLE 1, ROCS.
    Pièce jointe Snapshot 617.9 ko (source)

  • S. Curpanen, G. Poli, J. Oble, et A. Perez‐Luna, « C(sp2)−Si Bond Functionalization through Intramolecular Activation by Alkoxides », European Journal of Organic Chemistry, vol. 2021, nᵒ 7, p. 1055-1071, 2021.
    Résumé : Organosilicon reagents are invaluable tools in the hands of the modern chemist that allow accomplishing a number of synthetically useful transformations. While some are standard reactions, others are more complex transformations, such as the Brook rearrangement and its variants. This carbon-to-oxygen silyl migration represents a privileged method to generate transient carbanionic species well suited to undergo functionalization upon electrophilic substitution in the presence of an electrophile. This minireview focuses on recent advances in C(sp2)−Si bond functionalization through intramolecular activation by alkoxides. The key elements of reactivity will be highlighted in the introduction to allow the proper understanding of the migration process. Then, an overview of the reactivity of substrates incorporating the C(sp2)−Si motif and their synthetic applications will be provided.
    Mots-clés : Anion Relay Chemistry, Brook rearrangement, Hiyama cross-coupling, POLE 1, ROCS, Silyl migration, Synthetic methods.
    Pièce jointe Snapshot 484.1 ko (source)

  • K. de la Vega-Hernández, F. Chemla, F. Ferreira, O. Jackowski, et A. Perez-Luna, « Radical Germylzincation of Aryl- and Alkyl-Substituted Internal Alkynes », Organic Letters, vol. 23, nᵒ 11, p. 4426-4430, juin 2021.
    Résumé : The stereoselective germylzincation of internal alkynes delivering trisubstituted vinylgermanes is achieved via a radical chain process involving Ph3GeH and Et2Zn with AIBN as the initiator. Excellent levels of regiocontrol are observed for nonsymmetric (aryl, alkyl)-substituted alkynes and for propargylic alcohols with aryl-, alkyl-, or silyl-substituted alkynes. The germylzincation reaction can be combined in one pot with the Cu(I)-mediated electrophilic substitution of the C(sp2)–Zn bond to obtain synthetically challenging tetrasubstituted vinylgermanes.
    Mots-clés : POLE 1, ROCS.

  • K. de la Vega-Hernández, K. Isaac, F. Chemla, F. Ferreira, O. Jackowski, et A. Perez-Luna, « Radical Silyl- and Germylzincation of Propargylic Alcohols », Helvetica Chimica Acta, vol. 104, nᵒ 10, p. e2100128, 2021.
    Résumé : The silyl- and germylzincation of terminal or internal propargylic alcohols by reaction with (Me3Si)3SiH/Et2Zn, [(Me3Si)3Si]2Zn/Et2Zn or Ph3GeH/Et2Zn is examined. These reactions proceed through the addition of silicon- or germanium-centered radicals across the carbon≡carbon triple bond followed by the trapping by diethylzinc of the produced vinyl radical through homolytic substitution at the zinc atom. The influence of the hydroxy unit on the regio- and stereoselectivity of these reactions is discussed and compared to its role played in radical hydrosilylation and hydrogermylation reactions. Protocols developed to achieve the β-regioselective silylzincation of propargyl alcohol and the α-regioselective germylzincation of internal propargylic alcohols are particularly important, as they occur with trans stereoselectivity. For both procedures the C(sp2)−Zn bond remains available for subsequent in-situ electrophilic substitution leading overall to net alkyne trans difunctionalization.
    Mots-clés : germanium, germylmetalation, POLE 1, propargylic alcohols, radical reactions, ROCS, silylmetalation, zinc.

  • 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.

  • H. Dossmann, L. Fontaine, T. Weisgerber, V. Bonnet, E. Monflier, A. Ponchel, et C. Przybylski, « First Steps to Rationalize Host–Guest Interaction between α-, β-, and γ-Cyclodextrin and Divalent First-Row Transition and Post-transition Metals (Subgroups VIIB, VIIIB, and IIB) », Inorganic Chemistry, vol. 60, nᵒ 2, p. 930-943, janv. 2021.
    Mots-clés : CSOB, Cyclodextrin, POLE 3.

  • Y. Fu, Y. Ding, L. Zhang, Y. Zhang, J. Liu, et P. Yu, « Poly ethylene glycol (PEG)-Related controllable and sustainable antidiabetic drug delivery systems », European Journal of Medicinal Chemistry, vol. 217, p. 113372, 2021.

  • D. Gatineau, H. Dossmann, H. Clavier, A. Memboeuf, L. Drahos, Y. Gimbert, et D. Lesage, « Ligand effects in gold-carbonyl complexes: evaluation of the bond dissociation energies using blackbody infrared radiative dissociation », International Journal of Mass Spectrometry, p. 116545, févr. 2021.

  • A. Gillet, S. Cher, M. Tassé, T. Blon, S. Alves, G. Izzet, B. Chaudret, A. Proust, P. Demont, F. Volatron, et S. Tricard, « Polarizability is a key parameter for molecular electronics », Nanoscale Horizons, vol. 6, nᵒ 3, p. 271-276, mars 2021.
    Résumé : Identifying descriptors that govern charge transport in molecular electronics is of prime importance for the elaboration of devices. The effects of molecule characteristics, such as size, bulkiness or charge, have been widely reported. Herein, we show that the molecule polarizability can be a crucial parameter to consider. To this end, platinum nanoparticle self-assemblies (PtNP SAs) are synthesized in solution, including a series of polyoxometalates (POMs). The charge of the POM unit can be modified according to the nature of the central heteroatom while keeping its size constant. POM hybrids that display remote terminal thiol functions strongly anchor the PtNP surface to form robust SAs. IV curves, recorded by conductive AFM, show a decrease in Coulomb blockade as the dielectric constant of the POMs increases. In this system, charge transport across molecular junctions can be interpreted as variations in polarizability, which is directly related to the dielectric constant.
    Mots-clés : E-POM, POLE 2.
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  • A. Harbi, Y. L. Godec, Y. Li, H. Moutaabbid, S. Benmokhtar, et M. Moutaabbid, « Experimental and theoretical investigation of the electronic, magnetic, and optical properties of a new oxyphosphate, Ni0.25Mn0.25TiO(PO4) », Journal of Physics and Chemistry of Solids, vol. 148, p. 109633, 2021.
    Résumé : The structural, magnetic, and optical properties of a new oxyphosphate, Ni0.25Mn0.25TiOPO4, have been investigated by X-ray diffraction (XRD) analysis, magnetic FC-ZFC measurements, and vibrational spectroscopy (Raman, IR, WDS, and UV/visible). XRD analysis showed that the compound crystallizes in a monoclinic structure, space group P21/c, with unit cell parameters of a = 7.3758(2) Å, b = 7.3255(2) Å, c = 7.3448(2) Å, and β = 120.25(2)°. Elemental analysis of the powder confirmed the presence of Ni, Mn, Ti, and P therein. Raman and IR spectra show strong bands at 749 and 787 cm−1, respectively, attributable to the vibration of –Ti–O–Ti–O– bonds in infinite chains. Magnetic studies have been performed in the temperature range from 2 to 300 K. The results revealed a weak antiferromagnetic coupling between spins in Ni0.25Mn0.25TiOPO4. The band-gap energy was estimated as Eg = 1.99 eV based on UV/Vis spectrophotometry. To better understand the experimental data, density functional theory (DFT) computations were performed within the generalized gradient approximation (GGA) and GGA + U. The partial density of states (PDOS) shows strong hybridization between O 2p, Mn 3d, and Ni 3d in the valence band and between Mn 3d, Ni 3d, and Ti 3d in the conduction band.
    Mots-clés : ERMMES, POLE 2.

  • X. He, Y. Nie, M. Zhong, S. Li, X. Li, Y. Guo, Z. Liu, Y. Gao, F. Ding, D. Wen, et Y. Zhang, « New organoselenides (NSAIDs-Se derivatives) as potential anticancer agents: Synthesis, biological evaluation and in silico calculations », European Journal of Medicinal Chemistry, vol. 218, p. 113384, 2021.

  • J. - R. Jiménez, B. Xu, H. E. Said, Y. Li, J. von Bardeleben, L. - M. Chamoreau, R. Lescouëzec, S. Shova, D. Visinescu, M. - G. Alexandru, J. Cano, et M. Julve, « Field-induced single ion magnet behaviour of discrete and one-dimensional complexes containing [bis(1-methylimidazol-2-yl)ketone]-cobalt(II) building units », Dalton Transactions, vol. 50, nᵒ 44, p. 16353-16363, nov. 2021.
    Résumé : We describe herein the first examples of six-coordinate CoII single-ion magnets (SIMs) based on the β-diimine Mebik ligand [Mebik = bis(1-methylimidazol-2-yl)ketone]: two mononuclear [CoII(Rbik)2L2] complexes and one mixed-valence {CoIII2CoII}n chain of formulas [CoII(Mebik)(H2O)(dmso)(μ-NC)2CoIII2(μ-2,5-dpp)(CN)6]n·1.4nH2O (3) [L = NCS (1), NCSe (2) and 2,5-dpp = 2,5-bis(2-pyridyl)pyrazine (3)]. Two bidentate Mebik molecules plus two monodentate N-coordinated pseudohalide groups in cis positions build somewhat distorted octahedral surroundings around the high-spin cobalt(II) ions in 1 and 2. The diamagnetic [CoIII2(μ-2,5-dpp)(CN)8]2− metalloligand coordinates the paramagnetic [CoII(Mebik)(H2O)(dmso)]2+ complex cations in a bis-monodentate fashion to afford neutral zigzag heterobimetallic chains in 3. Ab initio calculations, and cryomagnetic dc (2.0–300 K) and ac (2.0–12 K) measurements as well as EPR spectroscopy for 1–3 show the existence of magnetically isolated high-spin cobalt(II) ions with D values of 59.84–89.90 (1), 66.32–93.90 (2) and 70.40–127.20 cm−1 (3) and field-induced slow relaxation of the magnetization, being thus new examples of SIMs with transversal magnetic anisotropy. The analysis of their relaxation dynamics reveals that the relaxation of the magnetization occurs by the Raman (with values of the n parameter covering the range 6.0–6.8) and direct spin-phonon processes.
    Mots-clés : ERMMES, POLE 2.

  • S. C. L. Kamerlin, D. J. Allen, B. de Bruin, E. Derat, et H. Urdal, « Journal Open Access and Plan S: Solving Problems or Shifting Burdens? », Development and Change

    , vol. n/a, nᵒ n/a, 2021.
    Résumé : 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.
    Mots-clés : MACO, POLE 1.
    Pièce jointe Snapshot 648.7 ko (source)
    Pièce jointe Full Text PDF 275.8 ko (source)

  • S. Khodjoyan, E. Remadna, H. Dossmann, D. Lesage, G. Gontard, J. Forté, H. Hoffmeister, U. Basu, I. Ott, P. Spence, Z. Waller, M. Salmain, et B. Bertrand, « [(C^C)Au(N^N)]+ complexes as a new family of anticancer candidates: synthesis, characterization and exploration of the antiproliferative properties », Chemistry – A European Journal, vol. n/a, nᵒ n/a, 2021.
    Résumé : A library of eleven cationic gold(III) complexes of the general formula [(C^C)Au(N^N)] + when C^C is either biphenyl or 4,4’-ditertbutyldiphenyl and N^N is a bipyridine, phenanthroline or dipyridylamine derivative have been synthesized and characterized. Contrasting effects on the viability of the triple negative breast cancer cells MDA-MB-231 was observed from a preliminary screening. The antiproliferative activity of the seven most active complexes were further assayed on a larger panel of human cancer cells as well as on non-cancerous cells for comparison. Two complexes stood out for being either highly active or highly selective. Eventually, reactivity studies with biologically meaningful amino acids, glutathione, higher order DNA structures and thioredoxin reductase (TrxR) revealed a markedly different behavior from that of the well-known coordinatively isomeric [(C^N^C)Au(NHC)] + structure. This makes the [(C^C)Au(N^N)] + complexes a new class of organogold compounds with an original mode of action.
    Mots-clés : Bioorganometallics, Biphenyl, Cancer, Chelate, CHEMBIO, CSOB, Gold, POLE 3.

  • G. Lemière, A. Millanvois, C. Ollivier, et L. Fensterbank, « A Parisian Vision of the Chemistry of Hypercoordinated Silicon Derivatives », The Chemical Record, vol. 21, nᵒ 5, p. 1119-1129, 2021.
    Résumé : 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.
    Mots-clés : 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, et 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.
    Résumé : 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.
    Mots-clés : MACO, POLE 1.

  • A. Li, L. - M. Chamoreau, B. Baptiste, Y. Li, Y. Journaux, et L. Lisnard, « Solvothermal synthesis, structure and magnetic properties of heterometallic coordination polymers based on a phenolato-oxamato co-bidentate-tridentate ligand », Dalton Transactions, vol. 50, nᵒ 2, p. 681-688, janv. 2021.
    Résumé : The use of solvothermal conditions has succesfully led to the preparation of heterometallic 1D coordination polymers from a co-bidentate-tridentate phenolato-oxamato ligand. The reaction of the N-(2-hydoxyphenyl)oxamic acid (ohpma) with acetate salts of transition metal ions at 80 °C has yielded the heterobimetallic [Cu(ohpma)M(OAc)(DMF)2] (M = Co (1); Mn (2)) and the heterotrimetallic [Cu(ohpma)Co0.57Mn0.43(OAc)(DMF)2] (3) chain compounds. Single-crystal and powder diffraction studies show that the polymers are isostructural. Magnetic studies suggest the existence of an inter-chain two-dimensional antiferromagnetic interaction taking place in compounds 1–3.
    Mots-clés : ERMMES, POLE 2.

  • A. Li, J. Forté, Y. Li, Y. Journaux, et L. Lisnard, « Synthesis, structure and magnetic properties of an oxamate-based 1D coordination polymer built on pentametallic links », Inorganica Chimica Acta, vol. 521, p. 120320, juin 2021.
    Résumé : The solvothermal reaction of the hexadentate 2-(oxamato)benzoic acid ligand (oaba) with copper(II) and cobalt(II) ions has yielded the [Cu4Co3(oaba)4(OH)2(DMF)6]·2(DMF)·1H2O (1) 1D coordination polymer. The single-crystal X-ray diffraction study reveals the formation of a neutral chain built from pentametallic complexes where each multi-polydentate ligand bridges four metal centres. The atypical morphology observed here for an oxamate-based 1D polymer arises from the use of a ligand bearing extra coordination sites. Magnetometry indicates strong dominating antiferromagnetic interactions within the polymer resulting in a non-zero ferrimagnetic state at low temperature.
    Mots-clés : ERMMES, POLE 2.

  • J. Liu, X. Ding, Y. Fu, C. Xiang, Y. Yuan, Y. Zhang, et P. Yu, « Cyclodextrins based delivery systems for macro biomolecules », European Journal of Medicinal Chemistry, vol. 212, p. 113105, 2021.

  • J. Liu, B. Wang, C. Przybylski, O. Bistri‐Aslanoff, M. Ménand, Y. Zhang, et M. Sollogoub, « Programmed Synthesis of Hepta‐Differentiated β‐Cyclodextrin: 1 out of 117655 Arrangements », Angewandte Chemie International Edition, vol. 60, nᵒ 21, p. 12090-12096, mai 2021.

  • S. Mabrouk, H. Rinnert, L. Balan, S. Blanchard, J. Jasniewski, G. Medjahdi, R. B. Chaabane, et R. Schneider, « Aqueous synthesis of highly luminescent ternary alloyed Mn-doped ZnSeS quantum dots capped with 2-mercaptopropionic acid », Journal of Alloys and Compounds, vol. 858, p. 158315, mars 2021.
    Résumé : Highly photoluminescent and water dispersible ternary alloyed Mn-doped ZnSeS and core/shell Mn:ZnSeS/ZnS quantum dots (QDs) with pure dopant emission were synthesized through a simple aqueous route using thiolactic acid (2-MPA) as a capping ligand. Transmission electron microscopy and X-ray diffraction show that Mn:ZnSeS nanocrystals are of spherical shape, with a diameter of 2.4 nm and a cubic zinc blende structure. With the overcoating of the ZnS shell, the particle size increases to 3.7 nm, which confirms the epitaxial growth of the shell on Mn:ZnSeS cores. The photoluminescence (PL) quantum yield depends on the Mn loading and reaches 22% for Mn:ZnSeS cores doped with 10% Mn and 41% after the growth of ZnS at the surface of the cores due to the effective elimination of surface-trap states. Mn:ZnSeS QDs exhibit also long PL lifetimes (up to 681 μs) indicating that the emission originates from the spin forbidden Mn2+ 4T1 → 6A1 transition. Electron paramagnetic resonance and X-ray photoelectron spectroscopy results suggest that Mn2+ ions are located at the interface of core/shell Mn:ZnSeS/ZnS QDs. Further, the stability of Mn:ZnSeS/ZnS QDs was also investigated along with their transfer in organic phase using octanethiol.
    Mots-clés : 2-Mercaptopropionic acid, Core/shell Mn:ZnSeS/ZnS, E-POM, Mn-doped ZnSeS, Photoluminescence, POLE 2, Quantum dots, Stability.

  • J. - P. Mahy, F. Avenier, W. Ghattas, R. Ricoux, et M. Salmain, « Current Applications of Artificial Metalloenzymes and Future Developments », in Enzymes for Solving Humankind's Problems: Natural and Artificial Systems in Health, Agriculture, Environment and Energy, J. J. G. Moura, I. Moura, et L. B. Maia, Éd. Cham: Springer International Publishing, 2021, p. 363-411.
    Résumé : In between traditional homogeneous metal catalysts and enzyme catalysts, a new class of hybrid catalysts named artificial metalloenzymes resulting from the controlled embedding of transition metal species (ions, synthetic inorganic or organometallic complexes) within natural, genetically-engineered or even de novo protein scaffolds currently undergoes a tremendous development at the academic level. This family of hybrid assemblies ideally combines the features of their individual components, allowing a wide range of chemical reactions, including new-to-nature reactions, to be catalyzed under mild, eco-compatible conditions with high chemo- and/or stereoselectivity. This chapter intends to summarize the most remarkable achievements in artificial metalloenzyme design and properties with emphasis put on industrially relevant chemical reactions, including oxidations, imine reductions, C–C and C–N bonds formation. It also gives an up-to-date survey on the most advanced applications of artificial metalloenzymes in cascade reactions and in vivo catalysis.
    Mots-clés : Carbene insertion, Cascade reactions, CHEMBIO, Directed evolution, In vivo catalysis, Metathesis, Oxidation, POLE 3, Polymerization, Reduction, Uncaging.

  • T. Martinez, A. Vanitcha, C. Troufflard, N. Vanthuyne, J. Forté, G. Gontard, G. Lemière, V. Mouriès-Mansuy, et 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.
    Résumé : 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.
    Mots-clés : asymmetric catalysis, carbene, DFT, gold, MACO, phosphine oxide, POLE 1.

  • Y. Mazouzi, A. Miche, A. Loiseau, B. Beito, C. Méthivier, D. Knopp, M. Salmain, et S. Boujday, « Design and Analytical Performances of a Diclofenac Biosensor for Water Resources Monitoring », ACS sensors, août 2021.
    Résumé : Because the broadly consumed pain killer diclofenac (DCF) is a recognized pollutant, monitoring of its concentration is routinely performed in surface waters. As a valuable alternative to chromatographic and immunochemical assays, we developed a piezoelectric immunosensor to quantify DCF, first in buffer (PBS) and then in river water samples. A sensing layer comprising DCF was built up on the surface of silica-coated quartz sensors using a robust coupling chemistry. Binding of a highly affine monoclonal anti-DCF antibody was monitored in real time by quartz crystal microbalance with dissipation (QCM-D) measurements from which were determined a dissociation constant KD of 0.24 nM and an acoustic antibody surface coverage of 1120 ng/cm2 at saturation. On the other hand, an optical antibody surface coverage of 260 ng/cm2 was determined by combined nanoplasmonic sensing measurement, giving a hydration percentage of 75% for the antibody monolayer. DCF assay was further set up following a competitive format for which binding of antibody to the sensing layer is inhibited by DCF in solution. The piezoelectric sensor response expressed as frequency shift ΔF was inversely related to the concentration of DCF with a dynamic range of 15-46 nM and a limit of detection (LoD) of 9.5 nM (2.8 μg/L) in PBS. This piezoelectric immunosensor was eventually applied to the assay of DCF in surface water samples taken at three different locations in the Seine and Marne rivers. The calculated concentration of DCF in these samples was in good agreement with official data published by the French center of water analysis eaufrance.
    Mots-clés : antibody, CHEMBIO, immunosensor, nanoplasmonics, nonsteroidal anti-inflammatory drug, POLE 3, quartz crystal microbalance.

  • C. Medena, C. Aubert, E. Derat, L. Fensterbank, G. Gontard, O. Khaled, C. Ollivier, N. Vanthuyne, M. Petit, et M. Barbazanges, « Helical Bisphosphinites in Asymmetric Tsuji-Trost Allylation: a Remarkable P:Pd Ratio Effect », ChemCatChem, vol. 13, nᵒ 21, p. 4543-4548, 2021.
    Résumé : 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.
    Mots-clés : chirality, helicene, homogeneous catalysis, MACO, phosphinite, POLE 1, Tsuji-Trost allylation.
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