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Accueil > Les équipes > Réactivité organométallique et catalyse pour la synthèse (ROCS) > Publications

Publications

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2017



  • M. Beaupérin, D. Polat, F. Roudesly, S. Top, A. Vessières, J. Oble, G. Jaouen, et G. Poli, « Approach to ferrocenyl-podophyllotoxin analogs and their evaluation as anti-tumor agents », Journal of Organometallic Chemistry.
    Résumé : Podophyllotoxin is a natural product endowed of a high antimitotic activity and a high affinity for tubulin. Its action results in the cessation of cell division, inducing cell death. However, its high toxicity restrains its use as drug. To overcome this drawback, several chemical modifications of the native podophyllotoxin have been made. However, to date, no reports have so far been directed toward incorporation of a metallocene moiety. The search for new organometallic drugs is a central field in drug discovery, including the domain of cancer therapy. In particular, metallocenyl moieties are known to increase or decrease, depending on the degree of conjugation in the organometallic motif, the selectivity of drugs toward cancer cells. The conjugate organometallic compound reduces the damage of healthy tissues, yet permitting the selective desired antimitotic and cytotoxic effects of the active principle. We report here the synthesis of ferrocene-containing podophyllotoxin analogs and preliminary antiproliferative tests.
    Mots-clés : Antitumor agent, Bioorganometallic chemistry, CHEMBIO, Ferrocene, Multi-step synthesis, Palladium, Podophyllotoxin, POLE 1, POLE 3, ROCS.


  • V. N. Bochatay, L. Debien, F. Chemla, F. Ferreira, O. Jackowski, et A. Perez-Luna, « Synthesis of allenylzinc reagents by 1,2-rearrangement of alkynyl(disilyl)zincates derived from acetylenic epoxides and acetylenic aziridines », Comptes Rendus Chimie.
    Résumé : Lithium alkynyl(disilyl)zincates obtained from metalated ethynyloxiranes, as well as from N-tert-butanesulfinyl(ethynyl)aziridines or N-tert-butanesulfonyl(ethynyl)aziridines, undergo 1,2-migration of the organosilyl group with ring opening of the oxirane or aziridine ring by SNi displacement. A developed protocol that involves nBuLi for the metalation step offers a straightforward approach to the corresponding δ-oxy- and δ-amino α-silyl allenylzinc intermediates. The reagents derived from the epoxides are amenable to subsequent in situ condensation with aldehydes or ketones to provide 1,3-diols but not those derived from aziridines that only react sluggishly in similar condensations.
    Mots-clés : alkynes, carbenoids, POLE 1, rearrangement, ROCS, silicon, Zinc.


  • T. Borelli, S. Brenna, G. Broggini, J. Oble, et G. Poli, « (Diacyloxyiodo)benzenes-Driven Palladium-Catalyzed Cyclizations of Unsaturated N-Sulfonylamides: Opportunities of Path Selection », Advanced Synthesis & Catalysis, vol. 359, nᵒ 4, p. 623-628.
    Résumé : A study of the palladium(II)-catalyzed cyclization of unsaturated N-sulfonylamides was undertaken, using (diacyloxyiodo)benzenes as terminal oxidizing agents. Different reactivities were observed as a function of the nature of the unsaturation (terminal vs. internal), or of the hypervalent iodine compound used (diacetoxyiodobenzene vs. bistrifluoroacetoxyiodobenzene). Proper parameter selection allows the direction of the cyclization to be chosen towards either a global aminoacetoxylation, an allylic amination via aminopalladation, or an allylic amination via allylic C–H activation.
    Mots-clés : allylic compounds, amination, C–H activation, homogeneous catalysis, Palladium, POLE 1, ROCS.


  • C. Fopp, K. Isaac, E. Romain, F. Chemla, F. Ferreira, O. Jackowski, M. Oestreich, et A. Perez-Luna, « Stereodivergent Synthesis of β-Heteroatom-Substituted Vinyl­silanes by Sequential Silylzincation–Copper(I)-Mediated Electrophilic­ Substitution », Synthesis, vol. 49, nᵒ 04, p. 724-735.
    Résumé : Thieme E-Books & E-Journals
    Mots-clés : POLE 1, ROCS.


  • A. Pontes da Costa, D. Rosa Nunes, M. Tharaud, J. Oble, G. Poli, et J. Rieger, « Pd(0)-Nanoparticles Embedded in Core-Shell Nanogels as Recoverable Catalysts for the Mizoroki-Heck Reaction », ChemCatChem, p. n/a-n/a.
    Résumé : Core-shell nanogels are attractive stabilizers and supports for catalytically active metallic nanoparticles. Herein, we present the synthesis and the characterization of a nanostructured well-defined core-shell nanogel with the ability to stabilize palladium(0) nanoparticles in its core. This hybrid nanogel displays a remarkable stability in both solid state and in solution. This feature allowed its successful application as catalyst for the Mizoroki-Heck reaction between n-butyl acrylate and a series of bromo- and iodo-arenes. The yields spanned from good to excellent, and catalyst recycling could be achieved up to three times without significant activity loss. Three-phase tests indicated that the hybrid nanogel acts as a Pd(0) nano-reservoir. The catalysis proceeds in a quasi-homogenous fashion, with part of the catalytic activity occurring outside the nanogel explaining the observed limited recyclability.
    Mots-clés : Core-Shell Nanogels by PISA, Mizoroki-Heck Reaction, Palladium, POLE 1, RAFT Dispersion Polymerization, Recycling, ROCS.


  • F. Roudesly, J. Oble, et G. Poli, « Metal-catalyzed CH activation/functionalization: The fundamentals », Journal of Molecular Catalysis A: Chemical, vol. 426, Part B, p. 275-296.
    Résumé : An isolated CH bond in a molecule has a very low reactivity owing to the large kinetic barrier associated to the CH bond cleavage and the apolar nature of this bond. For this reason, the selective reactivity of such a non-functional group is under active study since several decades and is still regarded as the Holy Grail in chemistry. Metal-catalyzed CH activation/functionalization chemistry allows the step-economical and original construction of CC as well as CO and CN bonds starting from hydrocarbons (or hydrocarbon fragments) without the need of prior non catalytic oxidation steps. Furthermore, it can be of utmost importance in the domain of multistep syntheses, and also in transformations of societal significance such as the conversion of methane into methanol. This tutorial review addresses to students and researchers who would like to become acquainted with this fascinating topic. After a brief historical introduction, the main mechanistic fundaments of metal-catalyzed CH activation are exposed. Then, a selection of seminal advances and conceptual breakthroughs are presented.
    Mots-clés : C-heteroatom bond formation, CC bond formation, CH activation, CH functionalization, Mechanistic study, POLE 1, ROCS.


  • I. Zelocualtecatl-Montiel, F. García-Álvarez, J. R. Juárez, L. Orea, D. Gnecco, A. Mendoza, F. Chemla, F. Ferreira, O. Jackowski, D. M. Aparicio, A. Perez-Luna, et J. L. Terán, « Asymmetric Tandem Conjugate Addition–Aldol Condensation with N-Acryloyloxazolidines Derived from 2-Phenylglycinol », Asian Journal of Organic Chemistry, vol. 6, nᵒ 1, p. 67-70.
    Résumé : The tandem 1,4-addition–aldol condensation reaction of diethylzinc, α,β-unsaturated chiral enantiopure oxazolidines derived from 2-phenylglycinol, and carbonyl compounds is disclosed. The reaction proceeds through a radical-polar crossover mechanism involving the aldol condensation of a trisubstituted zinc enolate through a Zimmerman–Traxler transition state. Installation of a 2-pyridine moiety at the hemiaminal position of the chiral auxiliary allows obtaining both excellent asymmetric induction and diastereoselectivity (up to >90 % de). The developed protocol is suitable for aromatic and aliphatic aldehydes, as well as ketones.
    Mots-clés : aldol reaction, chiral oxazolidines, Diastereoselectivity, domino reactions, POLE 1, radical-polar mechanism, ROCS.

2016



  • V. N. Bochatay, Z. Neouchy, F. Chemla, F. Ferreira, O. Jackowski, et A. Pérez-Luna, « 4-Amino-1-allenylsilanes from 4-Aminopropargylic Acetates through a Silylzincation/Elimination Sequence », Synthesis, vol. 48, nᵒ 19, p. 3287-3300.
    Résumé : Thieme E-Books & E-Journals
    Mots-clés : POLE 1, ROCS.


  • D. Diamante, S. Gabrieli, T. Benincori, G. Broggini, J. Oble, et G. Poli, « Dehydrogenative Allylic Aminations of But-3-enoic Acid Derivatives », Synthesis, vol. 48, nᵒ 19, p. 3400-3412.
    Résumé : Thieme E-Books & E-Journals
    Mots-clés : POLE 1, ROCS.


  • F. J. S. Duarte, G. Poli, et M. J. Calhorda, « Mechanistic Study of the Direct Intramolecular Allylic Amination Reaction Catalyzed by Palladium(II) », ACS Catalysis, vol. 6, nᵒ 3, p. 1772-1784.
    Résumé : DFT calculations (PBE1PBE/6-31G(d,p), Def2-TZVPPD) were performed to study the intramolecular C–H amination of an unsaturated carbamate catalyzed by [Pd(LL)(OAc)2] (2), where LL is the bis(sulfoxide) ligand PhS(O)(CH2)2S(O)Ph. The coordination takes place by an associative path over a trigonal-bipyramidal transition state. The LL ligand undergoes a coordination shift from κ2S,S to κ1S, leaving an open position for binding of the substrate (C═C). In the next step, the C–H activation, the transition state for the hydrogen abstraction from the substrate to form the σ-allyl complex has an energy of 124.0 kJ mol–1, which is the highest energy in the whole mechanism (TOF-determining transition state). The σ-allyl converts easily in the π-allyl, the acetic acid molecule leaving the coordination sphere. The remaining acetate receives the second hydrogen from the NH group, while the newly formed acetic acid molecule is replaced by the pendant arm of the LL ligand, and the cyclization takes place (nucleophilic attack). During these changes, the metal is reduced to Pd(0) in the form of the Pd(0) complex of the oxazolidinone product, the most stable species in the cycle (TOF-determining intermediate). Either the C–H activation or the Pd(0) oxidation may be the step determining the energy span of the reaction, depending on reaction conditions.
    Mots-clés : POLE 1, ROCS.


  • B. J. Fallon, V. Corcé, M. Amatore, C. Aubert, F. Chemla, F. Ferreira, A. Perez-Luna, et M. Petit, « A well-defined low-valent cobalt catalyst Co(PMe3)4 with dimethylzinc: a simple catalytic approach for the reductive dimerization of benzyl halides », New Journal of Chemistry, vol. 40, nᵒ 12, p. 9912-9916.
    Résumé : Herein, we report the first catalytic version of a cobalt-catalysed reductive homocoupling of benzyl halides which proceeds with low catalyst loadings (0.5 to 5 mol%). By synthetizing each cobalt intermediate we demonstrate that reaction proceeds through two single electron transfers (SET) and that dimethylzinc is only involved in the regeneration of the catalytic species.
    Mots-clés : MACO, POLE 1, ROCS.


  • B. J. Fallon, E. Derat, M. Amatore, C. Aubert, F. Chemla, F. Ferreira, A. Perez-Luna, et M. Petit, « C2-Alkylation and Alkenylation of Indoles Catalyzed by a Low-Valent Cobalt Complex in the Absence of Reductant », Organic Letters, vol. 18, nᵒ 9, p. 2292-2295.
    Résumé : Herein an extremely versatile, well-defined, low-valent cobalt catalyst [Co(PMe3)4] capable of intermolecular and intramolecular imine-directed C2-alkylation and alkenylation of indoles is reported. The reaction proceeds in the absence of reducing agents or additives, affording a range of substituted indoles and dihydropyrroloindoles in high yields and regioselectivities. With the aid of deuterium labeling studies and DFT (Density Functional Theory) calculations, a mechanism is proposed that is based on a Ligand-to-Ligand Hydrogen Transfer pathway.
    Mots-clés : MACO, POLE 1, ROCS.


  • C. Fopp, K. Isaac, E. Romain, F. Chemla, F. Ferreira, O. Jackowski, M. Oestreich, et A. Perez-Luna, « Stereodivergent Synthesis of β-Heteroatom-Substituted Vinyl­silanes by Sequential Silylzincation–Copper(I)-Mediated Electrophilic­ Substitution », Synthesis.
    Résumé : Thieme E-Books & E-Journals
    Mots-clés : POLE 1, ROCS.

  • D. Lebœuf, L. Marin, B. Michelet, A. Perez-Luna, R. Guillot, E. Schulz, et V. Gandon, « Harnessing the Lewis Acidity of HFIP through its Cooperation with a Calcium(II) Salt: Application to the Aza-Piancatelli Reaction », Chemistry (Weinheim an Der Bergstrasse, Germany), vol. 22, nᵒ 45, p. 16165-16171.
    Résumé : A method to extend the scope of the aza-Piancatelli reaction between 2-furylcarbinols and anilines is depicted. We found that 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) is the solvent of choice for this transformation, as it outcompetes the usual solvents in terms of rate and yield. Side reactions and other issues raised by the title reaction are prevented, thereby providing an avenue to complex molecules that were previously inaccessible. Lewis acidity studies and computations were carried out to unveil the role of HFIP. Based on these results, we propose that HFIP is, in fact, acting as a Lewis acid and that its acidity can be enhanced when combined with a calcium(II) salt.
    Mots-clés : alcohol, Calcium, cooperative catalysis, density functional calculations, electrocyclic reactions, POLE 1, ROCS.


  • M. M. Lorion, F. J. S. Duarte, M. J. Calhorda, J. Oble, et G. Poli, « Opening the Way to Catalytic Aminopalladation/Proxicyclic Dehydropalladation: Access to Methylidene γ-Lactams », Organic Letters, vol. 18, nᵒ 5, p. 1020-1023.
    Résumé : A new aerobic intramolecular palladium(II)-based catalytic system that triggers aminopalladation/dehydropalladation of N-sulfonylalkenylamides to give the corresponding methylidene γ-lactams has been identified. Use of triphenylphosphine and chloride anion as ligands is mandatory for optimal yields, and molecular oxygen can be used as the sole terminal oxidant. Scope and limitations of the methods are described. A mechanism is proposed on the basis of experimental results as well as density functional theory calculations.
    Mots-clés : POLE 1, ROCS.


  • M. M. Lorion, J. Oble, et G. Poli, « Palladium catalyzed oxidative aminations and oxylations: where are we? », Pure and Applied Chemistry, vol. 88, nᵒ 4, p. 381–389.
    Résumé : Selective product formation in the Pd-catalyzed cyclization of unsaturated amide and carboxylic acid derivatives is an intriguing and challenging task. We recently discovered that the oxidative intramo-lecular Pd(II)-catalyzed amination or oxylation of unsaturated N-su

    lfonyl carbamates, N-sulfonyl carbox-amides and carboxylic acids takes place through the involvement of cyclic (usually, 5-or 6-membered) aminopalladated (AmPIs) or oxypalladated (OxPI) intermediates. Such cyclic intermediates can undergo a variety of transformations such as distocyclic β-H elimination, oxidative acetoxylation or intramolecular car-bopalladation, depending upon the substrate and/or the reaction conditions. In the absence of appropriate reaction pathways, the cyclic nucleopalladated intermediates (NuPIs) simply engage in an inconsequential equilibrium with the initial substrate and other transformations occur such as allylic C–H activation or, in the particular case of allyl carbamates, [3,3]-sigmatropic rearrangement.
    Mots-clés : POLE 1, ROCS.


  • R. Maazaoui, M. Pin-Nó, K. Gervais, R. Abderrahim, F. Ferreira, A. Perez-Luna, F. Chemla, et O. Jackowski, « Domino Methylenation/Hydrogenation of Aldehydes and Ketones by Combining Matsubara's Reagent and Wilkinson's Catalyst », European Journal of Organic Chemistry, p. 5732-5737.
    Résumé : The methylenation/hydrogenation cascade reaction of aldehydes or ketones through a domino process involving two ensuing steps in a single pot is realized. The compatibility of Matsubara's reagent and Wilkinson's complex give a combination that allows, under dihydrogen, the transformation of a carbonyl function into a methyl group. This new method is suitable to introduce an ethyl motif from aromatic and aliphatic aldehydes with total chemoselectivity and total retention of α-stereochemical purity. The developed procedure is also extended to the introduction of methyl groups from ketones.
    Mots-clés : aldehydes, chemoselectivity, domino reactions, hydrogenation, ketones, Methylenation, POLE 1, ROCS.

  • J. Ramirez Hernandez, F. Chemla, F. Ferreira, O. Jackowski, J. Oble, A. Perez-Luna, et G. Poli, « tert-Butanesulfinamides as Nitrogen Nucleophiles in Carbon–Nitrogen Bond Forming Reactions », CHIMIA International Journal for Chemistry, vol. 70, nᵒ 1, p. 84-92.
    Résumé : The use of tert-butanesulfinamides as nitrogen nucleophiles in carbon–nitrogen bond forming reactions is reviewed. This field has grown in the shadow of the general interest in N-tert-butanesulfinyl imines for asymmetric synthesis and occupies now an important place in its own right in the chemistry of the chiral amine reagent tert-butanesulfinamide. This article provides an overview of the area and emphasizes recent contributions wherein the tert-butanesulfinamides act as chiral auxiliaries or perform as nitrogen donors in metal-catalyzed amination reactions.
    Mots-clés : amination, Chiral Nucleophiles, POLE 1, ROCS, Tert-Butanesulfinamide.

2015



  • R. Beniazza, E. Romain, F. Chemla, F. Ferreira, O. Jackowski, et A. Perez-Luna, « Zinc Radical Transfer Based Modular Approach to Enantiopure Alkylidene-β-Prol­ines from N-(tert-Butylsulfinyl)-α-(aminomethyl)acrylates », European Journal of Organic Chemistry, p. 7661-7665.
    Résumé : N-(tert-Butylsulfinyl)-α-(aminomethyl)acrylates with tethered silylated alkynes undergo a tandem 1,4-addition/carbozincation reaction upon exposure to dialkylzinc compounds in the presence of air. The process follows a zinc-radical-transfer mechanism and provides vinylzinc adducts that can react subsequently with electrophiles. High levels of chiral induction (dr > 90:10) from the tert-butylsulfinyl directing group are achieved during the radical 5-exo-dig cyclization by adding samarium(III) triflate. The sequence overall provides straightforward modular access to enantiopure (E)-4-alkylidene-β-prolines from tert-butanesulfinamide.
    Mots-clés : Amino acids, cyclization, POLE 1, radicals, ROCS, Synthetic methods, Tandem reactions, Zinc.


  • V. N. Bochatay, Y. Sanogo, F. Chemla, F. Ferreira, O. Jackowski, et A. Pérez-Luna, « Ring-Opening of N-tert-Butanesulfinylethynylaziridines with Lithium Tris(dimethylphenylsilyl)zincate: Stereoselective Access to 4-Amino-1-allenylsilanes », Advanced Synthesis & Catalysis, vol. 357, nᵒ 13, p. 2809-2814.
    Résumé : The ring-opening of N-tert-butanesulfinylethynylaziridines with lithium tris(dimethylphenylsilyl)zincate is reported. The reaction is demonstrated to be both stereoselective and stereospecific and to proceed through an anti-SN2′ process. Further deprotection of the nitrogen atom under mild conditions allows access to 4-amino-1-(dimethylphenylsilyl)allenes with high yields and levels of stereoselectivity.
    Mots-clés : allenes, Asymmetric synthesis, aziridines, Diastereoselectivity, POLE 1, ROCS, zincates.


  • G. Broggini, G. Poli, E. M. Beccalli, F. Brusa, S. Gazzola, et J. Oble, « Ruthenium-Catalyzed Hydroamination of Aminoallenes: an Approach to Vinyl Substituted Heterocycles », Advanced Synthesis & Catalysis, vol. 357, nᵒ 4, p. 677-682.
    Résumé : Heterosubstituted aminoallenes underwent smooth ruthenium-catalyzed intramolecular exo-hydroamination reactions yielding the corresponding five-, six-, or seven-membered 1,3-diaza- or 1,3-oxaza-heterocyclic structures. This procedure is a valuable and less expensive alternative to the already known transition metal-catalyzed hydroamination reactions of aminoallenes.
    Mots-clés : allenes, heterocycles, homogeneous catalysis, Hydroamination, POLE 1, ROCS, Ruthenium.


  • B. J. Fallon, E. Derat, M. Amatore, C. Aubert, F. Chemla, F. Ferreira, A. Perez-Luna, et M. Petit, « C–H Activation/Functionalization Catalyzed by Simple, Well-Defined Low-Valent Cobalt Complexes », Journal of the American Chemical Society, vol. 137, nᵒ 7, p. 2448-2451.
    Résumé : A facile C?H activation and functionalization of aromatic imines is presented using low-valent cobalt catalysts. Using Co(PMe3)4 as catalyst we have developed an efficient and simple protocol for the C?H/hydroarylation of alkynes with an anti selectivity. Deuterium-labeling experiments, DFT calculations coupled with the use of a well-defined catalyst have for the first time shed light on the elusive black box of cobalt catalyzed C?H functionalization.
    Mots-clés : MACO, POLE 1, ROCS.


  • F. Louafi, M. M. Lorion, J. Oble, et G. Poli, « Dichotomous Reaction Pathways for the Oxidative Palladium(II)-Catalyzed Intramolecular Acyloxylation of Alkenes », Synlett, vol. 26, nᵒ 16, p. 2237-2242.
    Résumé : Thieme E-Books & E-Journals
    Mots-clés : POLE 1, ROCS.

2014



  • I. Erray, J. Oble, G. Poli, et F. Rezgui, « Regioselective <i>S</i> -allylation of thiols with cyclic Baylis–Hillman acetates », Journal of Sulfur Chemistry, vol. 35, nᵒ 2, p. 128-136.
    Mots-clés : adducts, allyl sulfides, alpha-(nitroalkyl)enones, Baylis-Hillman, carbonates, catalyzed allylic alkylations, conjugate addition, esters, mild, nucleophiles, Nucleophilic substitution, POLE 1, replacement, ROCS, stereoselective-synthesis, sulfides.

  • I. Erray, F. Rezgui, J. Oble, et G. Poli, « Microwave-Assisted Palladium-Catalyzed Allylation of beta-Enaminones », Synlett, vol. 25, nᵒ 15, p. 2196-2200.
    Résumé : A new palladium-catalyzed approach for the C-allylation of beta-enaminones under microwave irradiation is reported. This methodology provides an easy access to a variety of alpha-allylated enaminones. The reaction takes place with the preservation of the enamine function, which is poised for further transformations towards nitrogen-containing heterocycles.
    Mots-clés : aldehydes, allyl acetate, Allylation, alpha-allylation, asymmetric allylic alkylation, direct alkenylation, domino sequence, enaminone, indoles, intramolecular heck reaction, microwave irradiation, nonaromatic enamides, Palladium, POLE 1, ROCS, sequential wittig, transition-metal.


  • C. Kammerer, G. Prestat, D. Madec, et G. Poli, « Synthesis of γ-Lactams and γ-Lactones via Intramolecular Pd-Catalyzed Allylic Alkylations », Accounts of Chemical Research, vol. 47, nᵒ 12, p. 3439-3447.
    Résumé : ConspectusLactones and lactams are a well-known class of natural products and can be used as building blocks in organic synthesis. In addition, they can be found in many natural sources and synthetic drugs and have a broad range of biological or odorant properties. Chemists can create these useful compounds through palladium catalysis, which is a highly efficient tool for organic synthesis and is conveniently functional group tolerant. In this Account, we describe our work over the past 15 years in intramolecular Pd-catalyzed allylations where we have tethered the nucleophile and the electrophile by either an amide or an ester moiety, to produce ?-lactams and ?-lactones. We discuss in detail how the nature of the heteroatom tether influences the regioselectivity of the reaction. For example, a ketone [?C(O)CH2?] tether leads to mixtures of 5-exo and 7-endo cyclization products, while ester or amide [?C(O)X?] tethers afford sole 5-exo products. However, in the case of X = O, we were required to overcome two issues in the synthesis of ?-lactones. First of all, the tethering ester function can compete with the allylic leaving group in the oxidative addition to the Pd(0) center. Second, in this case, the proportion of the conformers that have a suitable geometry for cyclization is very low. When we insert a juxtaposed silyl group on the allyl fragment, the molecule can undergo oxidative addition and functionalization of the lactone via Hiyama cross-coupling.We also performed DFT calculations on these systems, which allowed us to better understand the behavior of [?C(O)X?] and [?C(O)CH2?] tethers. Computations also let us rationalize the different reactivities that we observed as a function of the geometry (Z or E) of the starting substrates. In addition, we were able to synthesize natural products or analogs (α-kainic acid, isoretronecanol, and picropodophyllin). We could turn these allylation reactions into asymmetric transformations and incorporate them into domino sequences. Thus, an allylation/Mizoroki?Heck sequence allowed us to straightforwardly access an aza-analog of picropodophyllin, as well as reach the lysergic acid backbone. Finally, we found that through carbopalladation of allenes, we could efficiently synthesize the key ?3-allylpalladium intermediates that were then ready for allylation reactions.
    Mots-clés : acid, cyclizations, domino sequence, POLE 1, ROCS, route, silylated pyrrolidones.


  • F. Liron, J. Oble, M. M. Lorion, et G. Poli, « Direct Allylic Functionalization Through Pd-Catalyzed C-H Activation: Direct Allylic Functionalization by Pd-Catalyzed C-H Activation », European Journal of Organic Chemistry, vol. 2014, nᵒ 27, p. 5863-5883.
    Mots-clés : aerobic oxidative amination, Allylation, bond activation, c-h activation, free nonacidic conditions, homogeneous catalysis, hydrocarbon oxidation, molecular-oxygen, multistep electron-transfer, olefin-palladiumchlorid-komplexe, Palladium, POLE 1, POLE 2, Reaction mechanisms, ROCS, serial ligand catalysis, synthetic reactions, terminal olefins.
    Pièce jointe

  • M. M. Lorion, F. Nahra, V. L. Ly, C. Mealli, A. Messaoudi, F. Liron, J. Oble, et G. Poli, « Digging into the mechanism of oxidative Pd(II)-catalyzed aminations », Chimica Oggi-Chemistry Today, vol. 32, nᵒ 5, p. 30-34.
    Résumé : Although the Pd(II)-catalyzed alkene aminopalladation and allylic C-H activation have been much described in literature, the in-depth mechanism of such type of process is far from being a simple matter. This account focuses on the oxidative intramolecular Pd(II)-catalyzed amination of unsaturated N-sulfonyl carbamates and carboxamides, revealing that different mechanistic paths can be operative. In particular, after activation of the unsaturation by Pd(II) catalyst, aminopalladation can take place, affording the corresponding high-energy cyclic (5- or 6-membered) aminopalladated intermediate (AmPI). This latter can evolve along different pathways, such as: distocyclic beta-H elimination, oxidation by a strong terminal oxidant, or carbopalladation. Otherwise, the cyclic AmPI can lay dormant, in equilibrium with the initial substrate. In this case, alternative reactivities may take place, such as allylic C-H activation of the olefinic substrate, [3,3]-sigmatropic rearrangement, or decomposition.
    Mots-clés : alkenes, Allylic alkylation, aminopalladation, beta-hydride elimination, c-h activation, c-h alkylation, Catalysis, DFT calculations, dicationic palladium(ii), highly electrophilic site, molecular-oxygen, olefins, organic-synthesis, Palladium, platinum(ii) complexes, POLE 1, ROCS, [3,3]-sigmatropic rearrangement.


  • L. Mistico, E. Ay, V. Huynh, A. Bourderioux, F. Chemla, F. Ferreira, J. Oble, A. Perez-Luna, G. Poli, et G. Prestat, « Reactivity of tert-butanesulfinamides in palladium-catalyzed allylic substitutions », Journal of Organometallic Chemistry, vol. 760, p. 124-129.
    Mots-clés : 1,2-addition, Allylic substitution, alpha-diketones, amination, amines, asymmetric-synthesis, cyclization, Palladium, POLE 1, ROCS, Sulfinamide, sulfur-olefin ligands.
    Pièce jointe


  • J. Rajabi, M. M. Lorion, V. L. Ly, F. Liron, J. Oble, G. Prestat, et G. Poli, « Dormant versus Evolving Aminopalladated Intermediates: Toward a Unified Mechanistic Scenario in Pd <sup>II</sup> -Catalyzed Aminations », Chemistry - A European Journal, vol. 20, nᵒ 6, p. 1539-1546.
    Mots-clés : aerobic oxidative amination, allylic amination, aminopalladation, beta-hydride elimination, c-h activation, c-h alkylation, dicationic palladium(ii), highly electrophilic site, hydrocarbon oxidation, hypervalent iodine reagents, organic-synthesis, Palladium, platinum(ii) complexes, POLE 1, ROCS, terminal olefins, [3,3]-sigmatropic rearrangement.
    Pièce jointe


  • M. Rigamonti, G. Prestat, G. Broggini, et G. Poli, « Synthesis of 1,4-benzodiazepinones via palladium-catalysed allene carbopalladation/amination domino sequence », Journal of Organometallic Chemistry, vol. 760, p. 149-155.
    Résumé : Vinyl-substituted 1,4-benzodiazepinones were obtained in good yields (10 examples, 61–82% yield) via the reaction between N-allenyl anthranyl amides and aryl iodides under Pd(0) catalysis. This new single cycle catalytic domino transformation involves a C–C followed by an N–C bond formation.
    Mots-clés : 1,4-Benzodiazepinones, allene, amination, analogs, antagonists, asymmetric-synthesis, carboamination, Carbopalladation, derivatives, domino reactions, gaba(a) receptor, inhibitors, Palladium, POLE 1, potent, pyrrolobenzodiazepines, ROCS, route.
    Pièce jointe

  • E. Romain, C. Fopp, F. Chemla, F. Ferreira, O. Jackowski, M. Oestreich, et A. Perez-Luna, « Trans-Selective Radical Silylzincation of Ynamides », Angewandte Chemie-International Edition, vol. 53, nᵒ 42, p. 11333-11337.
    Résumé : The silylzincation of terminal ynamides is achieved through a radical-chain process involving (Me3Si)(3)SiH and R2Zn. A potentially competing polar mechanism is excluded on the basis of diagnostic control experiments. The unique feature of this addition across the CC bond is its trans selectivity. One-pot electrophilic substitution of the Csp2Zn bond by Cu-I-mediated CC bond formation and subsequent manipulation of the Csp2Si bond provides a modular access to Z-,-disubstituted enamides.
    Mots-clés : acetylenes, alkenes, carbon multiple bonds, catalyzed silylzincation, Copper, enamides, POLE 1, radical reactions, ROCS, silicon, silylcupration, silylmetalation, stereoselective-synthesis, terminal alkynes, vinylsilanes, Zinc.

2013



  • C. Caumes, N. Delsuc, R. Beni Azza, I. Correia, F. Chemla, F. Ferreira, L. Carlier, A. Perez Luna, R. Moumné, O. Lequin, et P. Karoyan, « Homooligomers of substituted prolines and β-prolines: syntheses and secondary structure investigation », New Journal of Chemistry, vol. 37, nᵒ 5, p. 1312-1319.
    Résumé : Homooligomers of enantiomerically pure (2S,3R)-3-methyl-proline, (3R,4R)-4-methyl-β-proline and (3R,4S)-3,4-dimethyl-β-proline were synthesized and studied using circular dichroism (CD) in water, methanol and propanol and using NMR in water. Changes in the far-UV CD spectrum were observed from dimers to hexa Prolines
    Mots-clés : POLE 1, ROCS, SSO.

  • F. Chemla, F. Dulong, F. Ferreira, et A. Perez-Luna, « Radical zinc-atom-transfer-based carbozincation of haloalkynes with dialkylzincs », Beilstein Journal of Organic Chemistry, vol. 9, p. 236-245.
    Résumé : The formation of alkylidenezinc carbenoids by 1,4- addition/carbozincation of dialkylzincs or alkyl iodides based on zinc atom radical transfer, in the presence of dimethylzinc with beta-(propargyloxy)enoates having pendant iodo- and bromoalkynes, is disclosed. Formation of the carbenoid intermediate is fully stereoselective at -30 degrees C and arises from a formal anti-selective carbozincation reaction. Upon warming, the zinc carbenoid is stereochemically labile and isomerizes to its more stable form.
    Mots-clés : alpha,alpha-disubstituted amino-acids, buttenberg-wiechell rearrangement, carbenoid formation, carbenoids, carbometallation, carbozincation, enantioselective reformatsky reaction, enolate derivatives, exchange-reactions, n-enoyloxazolidinones, nickel-catalyzed carbozincation, POLE 1, radicals, reactions involving organozinc, ROCS, SSO, tandem reaction, unactivated alkenes.


  • A. Denichoux, M. Cyklinsky, F. Chemla, F. Ferreira, et A. Pérez-Luna, « Conjugated Enyne Synthesis by Rearrangement of Acetylenic Epoxides Mediated by Low-Valence Organotitanium and Organozirconium Reagents », Synlett, vol. 24, nᵒ 08, p. 1001-1005.

  • A. Denichoux, L. Debien, M. Cyklinsky, M. Kaci, F. Chemla, F. Ferreira, et A. Perez-Luna, « Three-Carbon Homologation of Diorganozincs with Lithiated Acetylenic Epoxides », Journal of Organic Chemistry, vol. 78, nᵒ 1, p. 134-145.
    Résumé : Reaction of dialkylzincs with lithiated acetylenic epoxides is described to give zincates that undergo a 1,2-metallate rearrangement by an anti-S(N)2' pathway. This rearrangement occurs with the transfer of an alkyl or a silyl group affording allenylzinc intermediates. Allenic and/or homopropargylic alcohols are obtained upon hydrolysis. Quenching the reaction mixture with aldehydes or ketones is shown to give access to 2-alkynyl-1,3-diols in a stereoselective manner.
    Mots-clés : alpha-allenic alcohols, beta-hydroxy ketones, carbonyl-compounds, diastereoselective synthesis, homopropargylic alcohols, organic-synthesis, POLE 1, propargylic epoxides, ROCS, SSO, stereospecific synthesis, synthetic applications, zinc reagents.

  • M. M. Lorion, D. Gasperini, J. Oble, et G. Poli, « Palladium-Catalyzed Arylic/Allylic Aminations: Permutable Domino Sequences for the Synthesis of Dihydroquinolines from Morita-Baylis-Hillman Adducts », Organic Letters, vol. 15, nᵒ 12, p. 3050-3053.
    Résumé : An efficient palladium-catalyzed synthesis of 1,2-dihydroquinolines has been developed via the reaction between anilines and Morita-Baylis-Hillman adducts derived from o-bromobenzaldehyde. This new Pd(0)-catalyzed pseudo-domino type I sequence Involves a Buchwald-Hartwig arylic amination and an allylic amination. When starting from an o-bromo allylic alcohol, the chronology Is arylic amination/allylic arylation. However, the sequence reverses when the reaction is performed on the corresponding o-bromo allylic acetate.
    Mots-clés : acetates, Allylic alkylation, aromatic-amines, asymmetric-synthesis, cobalt nanoparticles, intramolecular heck reaction, one-pot synthesis, organic-synthesis, POLE 1, ring-closing metathesis, ROCS, sequential actions, SSO.

  • M. M. Lorion, B. Matt, S. Alves, A. Proust, G. Poli, J. Oble, et G. Izzet, « Versatile Post-functionalization of Polyoxometalate Platforms By Using An Unprecedented Range of Palladium-Catalyzed Coupling Reactions », Chemistry-a European Journal, vol. 19, nᵒ 38, p. 12607-12612.
    Mots-clés : Allylic alkylation, clusters, cross-coupling, CSOB, dawson, E-POM, head groups, Heck reaction, hybrid, Keggin, organic-inorganic hybrids, Palladium, POLE 1, POLE 2, POLE 3, Polyoxometalates, polyoxotungstates, POM, ROCS, SSO, surfaces, surfactants.

2012



  • J. Bejjani, C. Botuha, F. Chemla, F. Ferreira, S. Magnus, et A. Pérez-Luna, « Metallotropic Equilibrium and Configurational Stability of 3-Chloro-1-(trimethylsilyl)propargyl and -allenyl Metals: Comparative Study among Lithium, Titanium, and Zinc », Organometallics, vol. 31, nᵒ 13, p. 4876-4885.
    Résumé : A comparative study of the metallotropic equilibrium between 1-chloro-3-(trimethylsilyl)propargyl and -allenyl metals was undertaken by means of lithio-, titano-, and zinco-carbenoids. The lithium and zinc species were shown to react mainly in their allenic metallotropic forms, whereas the titanium species proved to react in both its propargylic and allenic forms. The configurational stability of these organometallics was next examined using a modification of the Hoffmann test. In each case, the organometallic was reacted with a chiral enantiopure electrophile. A comparison of the diastereomeric ratios obtained at low and high conversion rates of the reagent allows assessment of its configurational stability. The lithium species thus exhibited a configurational lability at ?125 °C in Trapp mixture on the time scale of its reaction with (+)-camphor, while the titanium analogue proved to be configurationally stable at ?40 °C in THF/Et2O on the time scale defined by its reaction with (S)-N-tritylprolinal. In the context of its reaction with the same electrophile, the zinc bromide species was proven to be partially labile from ?80 °C in THF and its dynamic kinetic resolution was investigated.
    Mots-clés : POLE 1, POLE 2, ROCS, SSO.


  • A. Boutier, C. Kammerer-Pentier, N. Krause, G. Prestat, et G. Poli, « Pd-Catalyzed Asymmetric Synthesis of N-Allenyl Amides and Their Au-Catalyzed Cycloisomerizative Hydroalkylation: A New Route Toward Enantioenriched Pyrrolidones », Chemistry – A European Journal, vol. 18, nᵒ 13, p. 3840–3844.
    Mots-clés : allene, dynamic kinetic asymmetric transformation, Gold, lactams, Palladium, POLE 1, ROCS, SSO.


  • G. Broggini, E. Borsini, A. Fasana, G. Poli, et F. Liron, « Transition-Metal-Catalyzed Hydroamination and Carboamination Reactions of Anthranilic Allenamides as a Route to 2-Vinyl- and 2-(α-Styryl)quinazolin-4-one Derivatives », European Journal of Organic Chemistry, vol. 2012, nᵒ 19, p. 3617–3624.
    Résumé : 2-Vinyl- and 2-(α-styryl)quinazolin-4-ones have been synthesized by intramolecular gold-catalyzed hydroamination and palladium-catalyzed carboamination of anthranilic allenamides, easily prepared by prototropic isomerization of the corresponding propargylamides. These procedures, which lead to N-Boc-protected quinazolinones, represent a more flexible alternative to the reported palladium-catalyzedamination of anthranilic allylamides, achievable only from N-tosylallylamides.
    Mots-clés : allenes, Gold, Hydroamination, nitrogen heterocycles, Palladium, POLE 1, POLE 2, ROCS, SSO, Synthetic methods.


  • S. Giboulot, F. Liron, G. Prestat, B. Wahl, M. Sauthier, Y. Castanet, A. Mortreux, et G. Poli, « Pd-catalyzed domino carbonylative–decarboxylative allylation: an easy and selective monoallylation of ketones », Chemical Communications, vol. 48, nᵒ 47, p. 5889-5891.
    Résumé : In the presence of an allyl alcohol, α-chloroacetophenones undergo an allyloxycarbonylation reaction followed by in situ decarboxylative allylation to selectively afford the corresponding monoallylated ketones via a Pd-catalyzed domino sequence. The scope of the reaction was extended to substituted α-chloroa
    Mots-clés : POLE 1, ROCS, SSO.


  • C. Kammerer-Pentier, A. Diez Martinez, J. Oble, G. Prestat, P. Merino, et G. Poli, « Dual reactivity of O-α-allenyl esters under palladium(0) catalysis: From carbopalladation/allylic alkylation domino sequence to decarboxylative allenylation », Journal of Organometallic Chemistry, vol. 714, p. 53-59.
    Résumé : In a mechanistically-oriented study, O-α-allenyl esters have been evaluated as potential substrates for Pd-catalyzed carbopalladation/allylic alkylation domino sequences and decarboxylative allenylation reactions. The domino sequence turned out to be feasible only with electron-deficient aryl iodides, thereby showing a narrower potential than that previously observed with the malonamide-based series. The decarboxylative allenylation of O-α-allenyl esters was also tested and turned out to be practicable with β-ketoester-based substrates and using specific basic conditions. Plausible reaction mechanisms are proposed to account for the observed reactivities.
    Mots-clés : allene, Decarboxylative allenylation, domino reactions, Lactone, Palladium, POLE 1, ROCS, SSO.

  • S. Ouizem, F. Chemla, F. Ferreira, et A. Perez-Luna, « Synthesis of Enantiopure 5-Substituted 2,3-Methanopyrrolidines by Cyclization of Enantiopure alpha-Branched alpha-N-Homoallylamino Nitriles », Synlett, p. 1374-1378.
    Résumé : The preparation of 5-substituted 2,3-methanopyrrolidines by the stereoselective cyclization of zincated alpha-amino nitriles derived from enantiopure alpha-branched homoallylamines has been investigated. The formation of trans adducts in excellent diastereoselectivities (up to > 98:2) and good yields (up to 71%) is observed. The absolute configuration and enantiomeric excess are dependent on the nitrogen protecting group.
    Mots-clés : aminocyclopropanes, analogs, asymmetric-synthesis, bicyclic compounds, carbenoids, complexes, cyclization, cyclopropanation, imines, peptidase-iv inhibitors, POLE 1, potent, proline, reagents, ROCS, SSO, stereoselective synthesis, Zinc.

  • B. Wahl, H. Bonin, A. Mortreux, S. Giboulot, F. Liron, G. Poli, et M. Sauthier, « A General and Efficient Method for the Alkoxycarbonylation of alpha-Chloro Ketones », Advanced Synthesis & Catalysis, vol. 354, nᵒ 16, p. 3105-3114.
    Résumé : The alkoxycarbonylation of alpha-chloro ketones with carbon monoxide in alcoholic solvents could be optimized to generate beta-keto esters in high yields using much lower catalyst loadings than previously reported in the literature. Among the different screened parameters, the nature of the ligand proved to be the most crucial one, the Xantphos ligand affording the highest yields. The scope of the reaction could then be extended to a wide variety of chloro ketones with different types of alcohols.
    Mots-clés : alkoxycarbonylation, allyl phosphates, alpha-chloro ketones, benzyl-chloride, beta,gamma-unsaturated esters, beta-ketoesters, bite angle, carbon monoxide, carbon-monoxide, carbonylation, Catalysis, complexes, Palladium, palladium-catalyzed alkoxycarbonylation, POLE 1, ROCS, SSO, synthetic applications.


  • B. Wahl, S. Giboulot, A. Mortreux, Y. Castanet, M. Sauthier, F. Liron, et G. Poli, « Straightforward Synthesis of Allylated Keto Esters: The Palladium-Catalysed Haloketone Alkoxycarbonylation/ Allylation Domino Reaction », Advanced Synthesis & Catalysis, vol. 354, nᵒ 6, p. 1077–1083.
    Résumé : The palladium-catalysed α-chloro ketone methoxycarbonylation and allylic alkylation reactions can be efficiently combined to provide a new catalytic domino reaction. The first, carbonylative, step generates the β-keto ester, which acts as the nucleophile in a subsequent allylation step. The use of allyl phenates in combination with Xantphos ligand are the key features allowing one to obtain the allylated β-keto esters in good yields
    Mots-clés : Allylic alkylation, carbon monoxide, Catalysis, domino reaction, POLE 1, ROCS, selectivity, SSO.

2011



  • X. Bantreil, G. Prestat, A. Moreno, D. Madec, P. Fristrup, P. - O. Norrby, P. S. Pregosin, et G. Poli, « γ- and δ-Lactams through Palladium-Catalyzed Intramolecular Allylic Alkylation: Enantioselective Synthesis, NMR Investigation, and DFT Rationalization », Chemistry – A European Journal, vol. 17, nᵒ 10, p. 2885–2896.
    Résumé : The Pd-catalyzed intramolecular allylic alkylation of unsaturated amides to give γ- and δ-lactams has been studied in the presence of chiral ligands. Ligand (R)-3,5-tBu-MeOBIPHEP (MeOBIPHEP=6,6’-dimethoxybiphenyl-2,2-diyl)bis(diphenylphosphine)) afforded the best results and allowed the cyclization reactions to take place in up to 94:6 enantiomeric ratio. A model Pd–allyl complex has been prepared and studied through NMR spectroscopic analysis, which provided insight into the processes responsible for the observed enantiomeric ratios. DFT studies were used to characterize the diastereomeric reaction pathways. The calculated energy differences were in good agreement with the experimentally observed enantiomeric ratios.
    Mots-clés : cyclization, density functional calculations, enantioselectivity, lactams, Palladium, POLE 1, ROCS, SSO.

  • S. Cacchi, G. Fabrizi, A. Goggiamani, A. Iazzetti, D. Madec, G. Poli, et G. Prestat, « Functionalized 2,3-dihydrofurans via palladium-catalyzed oxyarylation of alpha-allyl-beta-ketoesters », Organic & Biomolecular Chemistry, vol. 9, nᵒ 24, p. 8233-8236.
    Résumé : The palladium-catalyzed reaction of (hetero) aryl bromides, chlorides, and nonaflates with alpha-allyl-beta-ketoesters provides ready efficient access to functionalized 2,3-dihydrofurans. The reaction tolerates several useful substituents including chloro, fluoro, ether, ketone, ester, cyano, and nitro groups.
    Mots-clés : 4,5-dihydrofuran derivatives, efficient synthesis, facile synthesis, feist-benary reaction, manganese(iii) acetate, neoclerodane diterpenoids, one-step cyclization, POLE 1, ROCS, SSO, stereoselective-synthesis, substituted dihydrofurans, tetrasubstituted 2,3-dihydrofurans.

  • F. Chemla, F. Dulong, F. Ferreira, M. P. Nuellen, et A. Perez-Luna, « Radical Zinc-Atom Transfer Based Multicomponent Approaches to 3-Alkylidene-Substituted Tetrahydrofurans », Synthesis-Stuttgart, nᵒ 9, p. 1347-1360.
    Résumé : A domino 1,4-addition/alkyne carbozincation sequence based on a radical zinc-atom transfer process is disclosed. Two efficient multicomponent approaches to 3-alkylidenetetrahydrofurans from beta-(propargyloxy)enoates bearing pendant alkynes (including ynamides) have been established: one involving the direct addition of dialkylzincs, and the second involving the dimethylzinc-mediated addition of alkyl iodides. Both sequences utilize the stereoselective formation of intermediate alkylidenezincs well suited for in situ functionalization with electrophiles.
    Mots-clés : addition-cyclization, alkynes, alpha,alpha-disubstituted amino-acids, aza-claisen rearrangement, dialkylzinc compounds, enantioselective reformatsky reaction, intramolecular carbozincation, metalation, n-enoyloxazolidinones, nickel-catalyzed carbozincation, POLE 1, radicals, reactions involving organozinc, ROCS, stereoselective-synthesis, tandem reaction, Zinc.

  • M. Cyklinsky, C. Botuha, F. Chemla, F. Ferreira, et A. Perez-Luna, « Diastereoselective Synthesis of Enantiopure Homopropargylic N-tert-Butylsulfinylamines », Synlett, nᵒ 18, p. 2681-2684.
    Résumé : The diastereoselective synthesis of enantiopure homopropargylic amines by propargylation of various N-tert-butylsulfinylimines (tBS-imines) with 1-trimethylsilyl allenylzinc bromide is presented.
    Mots-clés : 1,2-amino alcohols, alpha-imino ester, amines, Asymmetric synthesis, asymmetric-synthesis, beta-amino alcohols, butanesulfinyl imines, Chiral auxiliaries, common intermediate, concise synthesis, imines, mediated allylation, POLE 1, racemic allenylzinc, ROCS, SSO, stereoselective-synthesis, Zinc.

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