38693-90-2Relevant academic research and scientific papers
Mizoroki-Heck Reaction of Unstrained Aryl Ketones via Ligand-Promoted C-C Bond Olefination
Wang, Mei-Ling,Xu, Hui,Li, Han-Yuan,Ma, Biao,Wang, Zhen-Yu,Wang, Xing,Dai, Hui-Xiong
supporting information, p. 2147 - 2152 (2021/04/05)
Mizoroki-Heck reaction of unstrained aryl ketone with acrylate/styrene is accomplished via palladium-catalyzed ligand-promoted C-C bond cleavage. Various (hetero)aryl ketones are compatible in the reaction, affording the alkene product in good to excellent yields. Further applications in the late-stage olefination of some drugs, natural products, and fragrance-derived aryl ketones demonstrate the synthetic utility of this protocol. By employing ketone as both the directing group and the leaving group, 1,2-bifunctionalization is achieved via sequential ortho-C-H alkylation/ipso-Heck olefination.
Reduction of Electron-Deficient Alkenes Enabled by a Photoinduced Hydrogen Atom Transfer
Larionova, Natalia A.,Ondozabal, Jun Miyatake,Cambeiro, Xacobe C.
supporting information, p. 558 - 564 (2020/12/07)
Direct hydrogen atom transfer from a photoredox-generated Hantzsch ester radical cation to electron-deficient alkenes has enabled the development of an efficient formal hydrogenation under mild, operationally simple conditions. The HAT-driven mechanism is supported by experimental and computational studies. The reaction is applied to a variety of cinnamate derivatives and related structures, irrespective of the presence of electron-donating or electron-withdrawing substituents in the aromatic ring and with good functional group compatibility. (Figure presented.).
A Photocatalytic Regioselective Direct Hydroaminoalkylation of Aryl-Substituted Alkenes with Amines
Larionova, Natalia A.,Ondozabal, Jun Miyatake,Smith, Emily G.,Cambeiro, Xacobe C.
supporting information, p. 5383 - 5388 (2021/07/26)
A photocatalytic method for the α-selective hydroaminoalkylation of cinnamate esters has been developed. The reaction involves the regioselective addition of α-aminoalkyl radicals generated from aniline derivatives or aliphatic amines to the α-position of unsaturated esters. The scope of aromatic alkenes was extended to styrenes undergoing hydroaminoalkylation with anti-Markovnikov selectivity, which confirms the importance of the aromatic group at the β-position. Simple scale-up is demonstrated under continuous flow conditions, highlighting the practicality of the method.
C–C Cross-Coupling Reactions of Organosilanes with Terminal Alkenes and Allylic Acetates Using PdII Catalyst Supported on Starch Coated Magnetic Nanoparticles
Patra, Debabrata,Panja, Subir,Saha, Amit
supporting information, p. 878 - 883 (2020/02/13)
Starch coated magnetic nanoparticles supported palladium catalyst has been explored to perform C–C cross coupling reactions, such as oxidative Heck coupling and Tsuji–Trost allylic coupling using organosilicon compounds as one of the coupling partners. The biopolymer coated magnetic catalyst was very easy to recover magnetically and was efficiently recycled in the subsequent batches. All the reactions were performed in air and thus the necessity of air and moisture free reaction condition is avoided. The present protocols show wide substrate scope and good yields of the products.
Templating effect of carbon nanoforms on highly cross-linked imidazolium network: Catalytic activity of the resulting hybrids with Pd nanoparticles
Campisciano, Vincenzo,Calabrese, Carla,Liotta, Leonarda Francesca,La Parola, Valeria,Spinella, Alberto,Aprile, Carmela,Gruttadauria, Michelangelo,Giacalone, Francesco
, (2019/05/10)
Two different carbon nanoforms (CNFs), namely multi-walled carbon nanotubes (MWCNTs) and carbon nanohorns (CNHs), have been chosen as support for the direct polymerization of a bis-vinylimidazolium salt. Transmission electron microscopy analyses revealed a templating effect of the CNFs on the growth of the polymeric network, which perfectly covers their whole surfaces creating a cylindrical or spherical coating for MWCNTs and CNHs, respectively. Subsequently, the CNFs-polyimidazolium have been used as stabilizers for Pd nanoparticles (Pd NPs), and the obtained materials have been characterized by means of analytical and spectroscopic techniques and then employed as easily recoverable and recyclable catalysts for Suzuki and Heck reactions. Quantitative conversions have been obtained in almost all the explored reactions, even employing low loading of catalyst (down to 0.007 mol%). Suzuki reactions were carried out in pure water under aerobic conditions. Both materials showed excellent activity and recyclability for the investigated C-C coupling reactions, with the CNHs-based material resulting slightly more active than the MWCNTs-based one due to a higher superficial exposure of Pd NPs.
SBA-15/POSS-Imidazolium Hybrid as Catalytic Nanoreactor: the role of the Support in the Stabilization of Palladium Species for C?C Cross Coupling Reactions.
Calabrese, Carla,Campisciano, Vincenzo,Siragusa, Fabiana,Liotta, Leonarda F.,Aprile, Carmela,Gruttadauria, Michelangelo,Giacalone, Francesco
, p. 3758 - 3767 (2019/05/15)
Supported imidazolium modified polyhedral oligomeric silsesquioxanes (POSS) on SBA-15 have been used as platform for Pd(II) species. The so-obtained material was firstly characterized by means of TGA, solid state NMR, TEM, XPS, SAXS, porosimetry and ICP-OES and it was successfully tested as pre-catalyst in C?C cross couplings, namely Suzuki-Miyaura and Heck reactions. In both cases, the solid proved to be highly efficient and easily recoverable from the reaction mixture. The recyclability was verified for up to seven cycles without showing any activity decrease. Interestingly, only Pd(II) was detected in the reused catalyst in the Heck reaction. Therefore, the versatility of the material was investigated by using various aryl halides. Our palladium nanocomposite was able to promote both Suzuki and Heck reactions down to 0.0007 mol% showing outstanding turnover frequency (TOF) values of 114,286 and 32,381 h?1, respectively. Comparison with the palladium catalyst on SiO2-POSS-imidazolium support showed interesting differences in terms of stabilization of Pd species and recyclability. The excellent outcome of the reactions could be ascribed to the textural properties of the SBA-15 support and the presence of the imidazolium-POSS nanocage within the pores of SBA-15, that worked as a sort of nanoreactor. (Figure presented.).
Evaluating aryl esters as bench-stable C(1)-ammonium enolate precursors in catalytic, enantioselective Michael addition-lactonisations
Young, Claire M.,Taylor, James E.,Smith, Andrew D.
supporting information, p. 4747 - 4752 (2019/05/24)
An evaluation of a range of aryl, alkyl and vinyl esters as prospective C(1)-ammonium enolate precursors in enantioselective Michael addition-lactonisation processes with (E)-trifluoromethylenones using isothiourea catalysis is reported. Electron deficient aryl esters are required for reactivity, with 2,4,6-trichlorophenyl esters providing optimal product yields. Catalyst screening showed that tetramisole was the most effective isothiourea catalyst, giving the desired dihydropyranone product in excellent yield and stereoselectivity (up to 90 : 10 dr and 98 : 2 er). The scope and limitations of this process have been evaluated, with a range of diester products being generated after ring-opening with MeOH to give stereodefined dihydropyranones with excellent stereocontrol (10 examples, typically ～90 : 10 dr and >95 : 5 er).
Design, synthesis, trypanocidal activity, and studies on human albumin interaction of novel s-alkyl-1,2,4-triazoles
Franklim, Tatiany N.,Freire-De-Lima, Leonardo,Chaves, Otávio A.,LaRocque-De-Freitas, Isabel F.,da Silva-Trindade, Joana D.,Netto-Ferreira, José C.,Freire-De-Lima, Célio G.,Decoté-Ricardo, Debora,Previato, José O.,Mendon?a-Previato, Lucia,De Lima, Marco E.F.
, p. 1378 - 1394 (2019/08/26)
Chagas disease is a neglected tropical disease caused by the hemoflagellated parasite Trypanosoma cruzi (Kinetoplastida). The only available drug to treat chagasic patients in Brazil, the nitroheterocycle benznidazole, is effective solely during the acute phase of the infection. There is accordingly a need to develop new therapeutic tools for the treatment of Chagas disease. This work reports the synthesis, trypanocidal evaluation and human serum albumin (HSA) interactions of a novel series of 1,2,4-triazoles. The new derivatives were synthesized via microwave irradiation in good yields. Most compounds showed toxic effects against T. cruzi with low toxicity to host cells. Three S-alkylated-triazoles showed the best activity profile against amastigotes, with half maximal inhibitory concentration (IC50) values of 3.95 ± 1.41, 4.15 ± 0.92 and 3.61 ± 0.65 μmol L-1, respectively. The interaction between HSA and 3-[(1E,3E)-4-(1,3-benzodioxol-5-yl)buta-1,3-dien-1-yl]-5-(butylthio)-4-cyclohexyl-4,5-dihydro-1H-1,2,4-triazole was investigated using multiple spectroscopic techniques and molecular docking, revealing that serum albumin is a potential endogenous carrier to this compound in the human bloodstream.
Magnetic dendritic polymer nanocomposites as supports for palladium: A highly efficient and reusable catalyst for Mizoroki-Heck and Suzuki-Miyaura coupling reactions
Ma, Rong,Yang, Pengbo,Bian, Fengling
, p. 4748 - 4756 (2018/03/21)
A novel catalyst Fe3O4@SiO2-Dendrimer-Pd based on palladium immobilized on magnetic dendritic polymer nanocomposites was successfully synthesized and characterized by FT-IR, EA, XRD, TEM, EDX, VSM and XPS. This nanocatalyst showed excellent catalytic activity for solvent-free Mizoroki-Heck reaction and Suzuki-Miyaura reaction in EtOH/H2O at a palladium loading of only 0.009 mol%. Moreover, the Fe3O4@SiO2-Dendrimer-Pd catalyst could be conveniently recovered by an external magnet and used consecutively five times with excellent yields. The remarkable catalytic performances and convenient magnetic separability of the Fe3O4@SiO2-Dendrimer-Pd catalyst make it promising for practical application.
Dimethylisosorbide (DMI) as a Bio-Derived Solvent for Pd-Catalyzed Cross-Coupling Reactions
Wilson, Kirsty L.,Murray, Jane,Sneddon, Helen F.,Jamieson, Craig,Watson, Allan J. B.
, p. 2293 - 2297 (2018/10/20)
Palladium-catalyzed bond-forming reactions, such as the ?-Suzuki-Miyaura and Mizoroki-Heck reactions, are some of the most broadly utilized reactions within the chemical industry. These reactions frequently employ hazardous solvents; however, to adhere to increasing sustainability pressures and restrictions regarding the use of such solvents, alternatives are highly sought after. Here we demonstrate the utility of dimethyl isosorbide (DMI) as a bio-derived solvent in several benchmark Pd-catalyzed reactions: Suzuki-Miyaura (13 examples, 62-100% yield), Mizoroki-Heck (13 examples, 47-91% yield), and Sonogashira (12 examples, 65-98% yield).
