Nos tutelles

CNRS

Rechercher





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

Publications

publié le , mis à jour le

2012



  • G. Bertrand, L. Tortech, D. Fichou, M. Malacria, C. Aubert, et V. Gandon, « An Improved Protocol for the Synthesis of [(η4-C4R4)Co(η5-C5H5)] Complexes », Organometallics, vol. 31, nᵒ 1, p. 126-132, janv. 2012.
    Résumé : The reaction of bulky alkynes C2R2 with (?5-C5H5)Co(CO)(dimethyl fumarate) under microwave irradiation provides complexes of the type [(?4-C4R4)Co(?5-C5H5)] in good to excellent yields. This protocol represents a significant improvement over those reported previously. In particular, the formation of insertion products such as cyclopentadienones or cyclohexadienes can be avoided. In addition, because of the exceptional stability of (?5-C5H5)Co(CO)(dimethyl fumarate), the reactions can be carried out in crude solvents. The easy access to [(?4-C4R4)Co(?5-C5H5)] complexes stimulated a study of their reactivity, notably under cross-coupling conditions.
    Mots-clés : COS, MACO, NASCO, POLE 1, POLE 2.

  • S. Blanchard, E. Derat, M. Desage-El Murr, L. Fensterbank, M. Malacria, et V. Mouries-Mansuy, « Non-Innocent Ligands: New Opportunities in Iron Catalysis », European Journal of Inorganic Chemistry, nᵒ 3, p. 376-389, janv. 2012.
    Résumé : Introduced in the late sixties, non-innocent (or redox) ligands have been extensively studied for their unusual and intriguing chemical behavior. Their ability to delocalize and/or provide electrons to the metal center of organometallic complexes confers them undisputable chemical interest and has proved valuable in the development of novel synthetic methodologies. This review will focus on the chemistry and applications of low-valent iron complexes bearing potentially non-innocent ligands. Because of the elusive nature of these ligands, and whenever possible, theoretical calculations and analysis of spectroscopic data will be presented in an effort to provide insights into the catalytic activity of the complexes.
    Mots-clés : 2-pi+2-pi cycloaddition, 2-state reactivity, ab-initio, COS, cross-coupling reactions, Density functional calculations, E-POM, electronic-structure, ethylene polymerization catalysts, h bond activation, Iron, Low-valent iron complexes, MACO, mechanistic aspects, Non-innocent ligands (NILs), olefin polymerization, POLE 1, POLE 2, POM, Redox chemistry, transition-metal complexes.


  • B. Braïda, E. Derat, S. Humbel, P. C. Hiberty, et S. Shaik, « The Valence Bond Workshop in Paris: The Phoenix Rises from the Ashes or, Has a Love Story with MO-Based Theories Begun? », ChemPhysChem, vol. 13, nᵒ 18, p. 4029-4030, 2012.

  • N. Dupre, C. Brazel, L. Fensterbank, M. Malacria, S. Thorimbert, B. Hasenknopf, et E. Lacôte, « Self-Buffering Hybrid Gold-Polyoxometalate Catalysts for the Catalytic Cyclization of Acid-Sensitive Substrates », Chemistry – A European Journal, vol. 18, nᵒ 41, p. 12962-12965, 2012.
    Mots-clés : allenes, asymmetric enamine catalysts, carbene nhc complexes, CHEMBIO, COS, Cycloisomerization, epoxidation, GOBS, Gold, Heterocycles, heteropoly compounds, highly efficient, Hydroamination, intercluster compound, MACO, organic-inorganic hybrid composites, oxidation, POLE 1, POLE 3, Polyoxometalates, polyoxotungstates, protonation, SUPRA.

  • A. Ekomie, G. Lefevre, L. Fensterbank, E. Lacote, M. Malacria, C. Ollivier, et A. Jutand, « Iron-Catalyzed Reductive Radical Cyclization of Organic Halides in the Presence of NaBH4: Evidence of an Active Hydrido Iron(I) Catalyst », Angewandte Chemie-International Edition, vol. 51, nᵒ 28, p. 6942-6946, 2012.
    Mots-clés : aromatic halides, bond formation, catalysis, chloride, complexes, COS, coupling reactions, Electrochemistry, grignard-reagents, heterocyclic carbene boranes, Hydrides, Hydrogen, Iron, MACO, POLE 1, radical reactions, sodium-borohydride, tin-free.


  • M. Fellah, G. Lhommet, et V. Mouriès-Mansuy, « Total Synthesis of Indolizidine (+)-223A », European Journal of Organic Chemistry, vol. 2012, nᵒ 3, p. 463–465, 2012.
    Résumé : We described the diastereoselective total synthesis of indolizidine (+)-223A in 10 % overall yield over 14 steps starting from 6-chlorohex-2-ynoate. Our strategy involved chain elongation through aldolization, the formation of the indolizidine skeleton by cyclization, and stereocontrolled hydrogenation.
    Mots-clés : Aldol reactions, Alkaloids, Heterocycles, MACO, Nitrogen­ heterocycles, POLE 1, Protecting groups, Total synthesis.

  • L. Fensterbank, J. - P. Goddard, M. Malacria, et C. Ollivier, « Homolytic Reduction of Onium Salts », Chimia, vol. 66, nᵒ 6, p. 425-432, 2012.
    Résumé : Onium salts have proved to be efficient sources of carbon-centered radicals. They can undergo homolytic reduction by single electron transfer (SET) and participate in subsequent synthetic transformations. This review aims to provide an overview on the behavior of onium salts including diazonium, sulfonium, selenonium, telluronium, phosphonium and iodonium cations toward various reductive methods such as radiolysis, electrolysis, photolysis or the use of SET reagents. Mechanistic and synthetic aspects are presented. Applications in polymers and materials science are not covered.
    Mots-clés : aryl diazonium salts, bond-cleavage, c-h arylation, COS, diaryliodonium salts, Diazoniums, electrochemical reduction, Iodoniums, MACO, one-electron reduction, Phosphoniums, POLE 1, pulse-radiolysis, radicals, redox catalysis, reduction, Selenoniums, substituted diphenyliodonium salts, sulfonium salts, Sulfoniums, Telluroniums.

  • T. Fukuyama, Y. Ohta, C. Brancour, K. Miyagawa, I. Ryu, A. - L. Dhimane, L. Fensterbank, et M. Malacria, « Rh-Catalyzed [5+1] and [4+1] Cycloaddition Reactions of 1,4-Enyne Esters with CO: A Shortcut to Functionalized Resorcinols and Cyclopentenones », Chemistry – A European Journal, vol. 18, nᵒ 23, p. 7243-7247, juin 2012.
    Résumé : We have developed novel Rh-catalyzed [n+1]-type cycloadditions of 1,4-enyne esters, which involve an acyloxy migration as a key step. The efficient preparation of functionalized resorcinols, including biaryl derivatives, from readily available 1,4-enyne esters and CO was achieved by Rh-catalyzed [5+1] cycloaddition accompanied by 1,2-acyloxy migration. When enyne esters had an internal alkyne moiety, the reaction proceeded by a [4+1]-type cycloaddition involving 1,3-acyloxy migration, leading to cyclopentenones.
    Mots-clés : 1, 4-enyne esters, acetates, acyloxy migration, alkynes, carbon-monoxide, carbonylation, complexes, COS, cycloaddition, Gold catalysis, ketene ligand, MACO, metal, phenol derivatives, POLE 1, propargylic esters, rhodium.

  • P. Garcia, Y. Evanno, P. George, M. Sevrin, G. Ricci, M. Malacria, C. Aubert, et V. Gandon, « Synthesis of Aminopyridines and Aminopyridones by Cobalt-Catalyzed [2+2+2] Cycloadditions Involving Yne-Ynamides: Scope, Limitations, and Mechanistic Insights », Chemistry – A European Journal, vol. 18, nᵒ 14, p. 4337-4344, avr. 2012.
    Résumé : An in-depth study of the cobalt-catalyzed [2+2+2] cycloaddition between yne-ynamides and nitriles to afford aminopyridines has been carried out. About 30 nitriles exhibiting a broad range of steric demand and electronic properties have been evaluated, some of which open new perspectives in metal-catalyzed arene formation. In particular, the use of [CpCo(CO)(dmfu)] (dmfu=dimethyl fumarate) as a precatalyst made possible the incorporation of electron-deficient nitriles into the pyridine core. Modification of the substitution pattern at the yne-ynamide allows the regioselectivity to be switched toward 3- or 4-aminopyridines. Application of this

    synthetic methodology to the construction of the aminopyridone framework using a yne-ynamide and an isocyanate was also briefly examined. DFT computations suggest that 3-aminopyridines are formed by formal [4+2] cycloaddition between the nitrile and the intermediate cobaltacyclopentadiene, whereas 4-aminopyridines arise from an insertion pathway.
    Mots-clés : alkynes, alpha,omega-diynes, atom economy, c-c, cobalt, COS, cycloaddition, cyclobutadiene complexes, derivatives, isocyanates, MACO, nitriles, nitrogen heterocycles, organic-synthesis, POLE 1, reaction mechanisms, Reactive intermediates, substituted pyridines.

  • M. - H. Larraufie, G. Maestri, M. Malacria, C. Ollivier, L. Fensterbank, et E. Lacote, « The Cyanamide Moiety, Synthesis and Reactivity », Synthesis-Stuttgart, vol. 44, nᵒ 9, p. 1279-1292, mai 2012.
    Résumé : The cyanamide moiety provides many opportunities as a building block for the synthesis of nitrogen-containing heterocycles. This review discusses the reported methods for the preparation of alkyl-and N-acylcyanamides and illustrates their reactivity vis-a-vis nucleophilic additions, cycloadditions, radical chemistry and coordination chemistry.
    Mots-clés : allyl cyanamides, butyl-n-chlorocyanamide, catalyzed 2+2+2 cycloaddition, COS, cyanamide, cyanation, efficient synthesis, heterocycles, MACO, mixed-valence complexes, nitrogen, nitrogen ligands, one-flask transformation, one-pot synthesis, phenylcyanamide ligands, POLE 1, ruthenium(ii) complexes, sodium bis(trimethylsilyl)amide.


  • G. Maestri, M. - H. Larraufie, C. Ollivier, M. Malacria, L. Fensterbank, et E. Lacôte, « Rearrangements of N-Acyl Isothioureas. Alternate Access to Acylguanidines from Cyanamides », Organic Letters, vol. 14, nᵒ 21, p. 5538-5541, nov. 2012.
    Résumé : We report a tin-free one-pot radical approach to the synthesis of N-acyl isothioureas and acylguanidines from N-acyl cyanamides. Photoactivated reduction of aromatic disulfides in the presence of Hünig?s base results in hydrothiolation of the cyanamide moiety, followed by spontaneous 1,3-migration of the acyl group. Onward reaction of the isothioureas obtained with amines led to the corresponding N-acylguanidines, where the acyl group is attached to the nitrogen atom formerly at the cyano-end of the starting material.
    Mots-clés : COS, MACO, POLE 1.


  • A. C. Neves, H. M. Aitken, S. H. Kyne, L. Fensterbank, E. Lacôte, M. Malacria, C. Ollivier, et C. H. Schiesser, « Intramolecular homolytic substitution of seleninates – a computational study », Tetrahedron, vol. 68, nᵒ 1, p. 323-328, janv. 2012.
    Résumé : Ab initio and density functional theory (DFT) calculations predict that intramolecular homolytic substitution by alkyl radicals at the selenium atom in seleninates proceeds through smooth transition states in which the attacking and leaving radicals adopt a near collinear arrangement. When forming a five-membered ring and the leaving radical is methyl, G3(MP2)-RAD calculations predict that this reaction proceeds with an activation energy (ΔE1‡) of 30.4 kJ mol−1. ROBHandHLYP/6-311++G(d,p) calculations suggest that the formation of five-membered rings through similar intramolecular homolytic substitution by aryl radicals, with expulsion of phenyl radicals, proceeds with the involvement of a hypervalent intermediate. This intermediate further dissociates to the observed products, with overall energy barriers of about 40 kJ mol−1. Homolytic addition to the phenyl group was found not to be competitive with substitution, with a calculated barrier of 57.6 kJ mol−1. This computational study provides insight into homolytic substitution chemistry involving seleninates.
    Mots-clés : Computational chemistry, COS, homolytic substitution, MACO, POLE 1, Radical, Seleninates, selenium.


  • C. Queffélec, M. Petit, P. Janvier, D. A. Knight, et B. Bujoli, « Surface Modification Using Phosphonic Acids and Esters », Chemical Reviews, vol. 112, nᵒ 7, p. 3777-3807, 2012.


  • J. Rieger, T. Antoun, S. - H. Lee, M. Chenal, G. Pembouong, J. Lesage de la Haye, I. Azcarate, B. Hasenknopf, et E. Lacôte, « Synthesis and Characterization of a Thermoresponsive Polyoxometalate–Polymer Hybrid », Chemistry – A European Journal, vol. 18, nᵒ 11, p. 3355–3361, 2012.
    Résumé : We report the synthesis of the first organo-POM with thermoresponsive properties. Our concept will provide chemists with a new tool to design POMs whose solubility is reversibly controllable through an external stimulus. POM–polymer TBA7[POM]-poly(N,N-diethylacrylamide) (POM–PDEAAm), was prepared by grafting PDEAAm-NH2 (obtained by RAFT polymerization) onto the activated Dawson acyl-POM, α2-[P2W17O61SnCH2CH2C(O)]6−. Extensive MS analysis was used to monitor the chain-functionalization steps and to confirm the formation of the hybrid. Aqueous solutions of the (NH4)7[POM–PDEAAm] exhibited a LCST of 38 °C. Thus, the solubility/aggregation of the hybrid was reversibly controlled by changing the temperature. Above 38 °C, the solution became cloudy, and cleared again upon cooling. Dynamic light scattering (DLS) revealed the formation of small aggregates in the range 100 nm. We assumed that the charged POM head units prevented the formation of the larger-scattering aggregates that are usually observed for PDEAAm, and promoted the formation of micelle-like structures. The conjugate exhibited a temperature transition, which was different from that of the polymer and depended on the counterions associated with the POM. This result demonstrates the potential for merging organic (in this case, polymer) and inorganic structures to afford materials that exhibit new properties.
    Mots-clés : aggregation, COS, GOBS, MACO, organic-inorganic hybrid composites, POLE 1, POLE 3, POLE 4, POLYMERES, polymerization, Polyoxometalates, SUPRA, thermoresponsive polymers.


  • M. - A. Tehfe, J. Monot, M. Malacria, L. Fensterbank, J. - P. Fouassier, D. P. Curran, E. Lacôte, et J. Lalevée, « A Water-Compatible NHC-Borane: Photopolymerizations in Water and Rate Constants for Elementary Radical Reactions », ACS Macro Letters, vol. 1, nᵒ 1, p. 92-95, janv. 2012.
    Résumé : Rate constants for important elementary reactions of 2,4-dimethyl-1,2,4-triazol-3-ylidene borane (1) and its derived boryl radical have been measured in the presence and absence of water. Reactions including H-abstraction by tBuO?, and onward reactions of the derived radical with methyl acrylate (addition), iodopropane (halogen abstraction), and an iodonium salt (oxidation) are unaffected by the presence of a high concentration (1.5 M) of water. Extending these results, borane (1) has been found to be an efficient new co-initiator for the visible light photopolymerization of monomers in the presence of both air and water.
    Mots-clés : COS, MACO, POLE 1.


  • Q. Zhao, D. Curran, M. Malacria, L. Fensterbank, J. - P. Goddard, et E. Lacôte, « NHC-Catalyzed Chemo- and Regioselective Hydrosilylation of Carbonyl Derivatives », Synlett, vol. 23, nᵒ 03, p. 433-437, janv. 2012.

Année non précisée



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


  • L. G. Fensterbank, E. Levernier, K. Jaouadi, H. - R. Zhang, V. Corcé, A. Bernard, G. Gontard, C. Troufflard, L. Grimaud, E. Derat, et C. Ollivier, « Phenyl Silicates with Substituted Catecholate Ligands: Synthesis, Structural Studies and Reactivity », Chemistry – A European Journal, vol. n/a, nᵒ n/a, sans date.
    Résumé : While the generation of aryl radicals by photoredox catalysis is well-documented under reductive conditions, it has remained challenging under an oxidative pathway. Because of the easy photooxidation of alkyl bis-catecholato silicates, a general study on phenyl silicates bearing substituted catecholate ligands has been achieved. The newly synthesized phenyl silicates have been fully characterized and their reactivity has been explored. It was found that thanks to the substitution of the catecholate moiety and notably with the 4-cyanocatecholato ligand, the phenyl radical could be generated and trapped. Computational studies provided a rationale for these findings.
    Mots-clés : catalysisDFT, CHEMBIO, MACO, photoredox, radical, redox, silicatesphenyl.
    Pièce jointe Full Text PDF 2.2 Mo (source)
    Pièce jointe Snapshot 535.1 ko (source)
--- Exporter la sélection au format