551-93-9Relevant academic research and scientific papers
Photoinduced Reduction of Nitroarenes Using a Transition-Metal-Loaded Silicon Semiconductor under Visible Light Irradiation
Tsutsumi, Ken,Uchikawa, Fumito,Sakai, Kentaro,Tabata, Kenji
, p. 4394 - 4398 (2016)
We investigated transition-metal-loaded silicon nanoparticles for the photocatalytic reduction of nitroarene derivatives in the presence of formic acid under visible light irradiation. Formic acid assumes the role of both a hydrogen source and a sacrificial reagent for the introduction of electrons into the generated holes of semiconductors. As such, in the presence of formic acid, photocatalytic reactions smoothly proceed under mild conditions without gaseous hydrogen. In particular, palladium-loaded silicon (Pd/Si) was the most suitable catalyst for the conversion of nitrobenzene to aniline, compared to Pt/Si, Ru/Si, and Pd/C.
PqsBC, a condensing enzyme in the biosynthesis of the pseudomonas aeruginosa quinolone signal: Crystal structure, inhibition, and reaction mechanism
Drees, Steffen Lorenz,Li, Chan,Prasetya, Fajar,Saleem, Muhammad,Dreveny, Ingrid,Williams, Paul,Hennecke, Ulrich,Emsley, Jonas,Fetzner, Susanne
, p. 6610 - 6624 (2016)
Pseudomonas aeruginosa produces a number of alkylquinolone- type secondary metabolites best known for their antimicrobial effects and involvement in cell-cell communication. In the alkylquinolone biosynthetic pathway, the β-ketoacyl-(acyl carrier protein) synthase III (FabH)-like enzyme PqsBC catalyzes the condensation of octanoyl-coenzyme A and 2-aminobenzoylacetate (2-ABA) to form the signal molecule 2-heptyl- 4(1H)-quinolone. PqsBC, a potential drug target, is unique for its heterodimeric arrangement and an active site different from that of canonical FabH-like enzymes. Considering the sequence dissimilarity between the subunits, a key question was how the two subunits are organized with respect to the active site. In this study, the PqsBC structure was determined to a 2 A￠ resolution, revealing that PqsB and PqsC have a pseudo-2-fold symmetry that unexpectedly mimics the FabH homodimer. PqsC has an active site composed of Cys-129 and His-269, and the surrounding active site cleft is hydrophobic in character and approximately twice the volume of related FabH enzymes that may be a requirement to accommodate the aromatic substrate 2-ABA. From physiological and kinetic studies, we identified 2-aminoacetophenone as a pathway-inherent competitive inhibitor of PqsBC, whose fluorescence properties could be used for in vitro binding studies. In a time-resolved setup,wedemonstrated that the catalytic histidine is not involved in acyl-enzyme formation, but contributes to an acylation-dependent increase in affinity for the second substrate 2-ABA. Introduction of Asn into the PqsC active site led to significant activity toward the desamino substrate analog benzoylacetate, suggesting that the substrate 2-ABA itself supplies the asparagine- equivalent amino function that assists in catalysis.
Synthesis of functionalised 2,3-dihydroquinolin-4(1: H)-ones vs. quinoline or N -alkenylindole derivatives through sequential reactions of 2-alkynylanilines with ketones
Marsicano, Vincenzo,Arcadi, Antonio,Chiarini, Marco,Fabrizi, Giancarlo,Goggiamani, Antonella,Iazzetti, Antonia
, p. 421 - 438 (2021)
This study describes diversity-oriented synthesis of 2,2,3-substituted-2,3-dihydroquinolin-4(1H)-ones vs. functionalised quinoline or N-alkenylindole derivatives through Br?nsted acid mediated or Lewis acid catalyzed sequential reactions of 2-alkynylanilines with ketones. In particular, a series of challenging quinolin-4-one derivatives are prepared with good functional group tolerance in an atom-economical fashion by using p-toluenesulfonic acid monohydrate as a promoter of the reaction of ketones with 2-alkynylanilines in EtOH at reflux, while the same starting materials give the corresponding 4-substituted quinolines in toluene at 110 °C both in the presence of p-toluenesulfonic acid monohydrate as the promoter and FeCl3 as the catalyst. The divergent formation of N-alkenylindole derivatives occurs by switching to the use of ZnBr2 as the catalyst under the same reaction conditions. Conversely, only 4-methylsubstituted quinoline derivatives were isolated by reacting 2-ethynylanilines and/or 2-trimethylsylilanilines with ketones in all examined cases. This journal is
Catalytic Synthesis of 3-Substituted Indoles using CO as Building Block and Supported Rhodium as Catalyst
Ucciani, Eugene,Bonfand, Andre
, p. 82 - 83 (1981)
Under hydroformylation conditions, using supported rhodium as catalyst, 2-nitrostyrene is directly converted into skatole in ca. 70percent yield, by a reaction involving formation of 2-(o-nitrophenyl)propionaldehyde by homogeneous catalysis, reduction of the nitro-group by heterogeneous catalysis, then ring closure and thermal dehydration.
Selective hydrogenation of nitroarenes using an electrogenerated polyoxometalate redox mediator
Macdonald, Lewis,Rausch, Benjamin,Symes, Mark D.,Cronin, Leroy
, p. 1093 - 1096 (2018)
The 2-electron reduced form of the polyoxometalate silicotungstic acid (H4[SiW12O4]) is shown to be an effective and selective hydrogenation agent for a range of nitroarenes without the need for any co-catalyst. The ease of generation of the active species and its recyclability suggest that a new approach to this important class of chemical conversions is possible.
High catalytic activity of a bimetallic AgPd alloy supported on UiO-66 derived porous carbon for transfer hydrogenation of nitroarenes using formic acid-formate as the hydrogen source
Cheng, Saisai,Shang, Ningzhao,Zhou, Xin,Feng, Cheng,Gao, Shutao,Wang, Chun,Wang, Zhi
, p. 9857 - 9865 (2017)
Bimetallic AgPd nanoparticles anchored on metal-organic framework (UiO-66) derived N-doped porous carbon (NPC-UiO-66) was fabricated and used as a catalyst for the catalytic transfer hydrogenation of nitroarenes using formic acid-formate as the hydrogen source. The results demonstrated that the Ag1Pd9@NPC-UiO-66 composite exhibited extraordinary catalytic activity toward the hydrogenation of nitroarenes to anilines at room temperature. A series of substituted nitroarenes were successfully converted to the corresponding anilines in high yields under ambient conditions with other reducible groups remaining intact. The superior catalytic performance of the prepared catalyst can be attributed to the synergistic effect between the highly dispersed AgPd nanoparticles and the unique structure of the NPC-UiO-66 support, as well as the high adsorption ability of the catalyst for the nitroarenes.
A facile reduction of aromatic nitro compounds to aromatic amines with bis(cyclopentadienyl)titanium(IV) dichloride-indium system
Yoo, Byung Woo,Lee, Sung Jae,Yoo, Byoung Seung,Choi, Kyung Il,Kim, Joong Hyup
, p. 2489 - 2493 (2002)
Cp2TiCl2/In system was found to be a new reagent for reducing various aromatic nitro compounds to the corresponding aromatic amines in good yields under mild and neutral conditions.
Palladium(II)-mediated oxidative cyclization of N-carbamoyl aminoalkynes: A new route to γ-lactams
Doan, Huynh Dong,Gore, Jacques,Vatele, Jean-Michel
, p. 6765 - 6768 (1999)
Transformation of N-carbamoyl or acetyl-4-trimethylsilyl-3-alkyn-1-amines to diversely substituted 2-pyrrolidinones, via a Wacker-type reaction, is described.
Pd nanoparticles supported on a covalent triazine-based framework material: An efficient and highly chemoselective catalyst for the reduction of nitroarenes
Li, Jie,Zhang, Lihong,Liu, Xiaotong,Shang, Ningzhao,Gao, Shutao,Feng, Cheng,Wang, Chun,Wang, Zhi
, p. 9684 - 9689 (2018)
Pd nanoparticles anchored on a covalent triazine framework (Pd@CTF) were fabricated and employed to catalyze the transfer hydrogenation of nitro-compounds with formic acid as the hydrogen source. The results demonstrated that Pd@CTF displayed excellent catalytic activity and high chemoselectivity for the hydrogenation reaction at room temperature. Various substituted nitro-compounds were successfully converted to the corresponding amines in 0.2-2.5 h with other reducible functional moieties remaining intact. The high performance of Pd@CTF can be attributed to the synergistic interaction between the highly dispersed Pd nanoparticles and the covalent triazine framework support. The Pd@CTF catalyst can be readily reused for at least five consecutive runs without an obvious loss of its catalytic activity.
Intercalating ultrathin polymer interim layer for charge transfer cascade towards solar-powered selective organic transformation
Fu, Xiao-Yan,Hou, Shuo,Lin, Hua-Jian,Lin, Xin,Mo, Qiao-Ling,Wei, Zhi-Quan,Xiao, Fang-Xing,Xu, Shuai
, p. 150 - 161 (2021)
Transition metal chalcogenide quantum dots (TMCs QDs) constitute a crucial sector of semiconductors on account of large absorption coefficient for light harvesting, peculiar quantum confinement effect, and abundant active sites stemming from ultra-small size. However, elaborate and tunable modulation of anisotropic photoinduced charge carriers over TMCs QDs represents an enduring challenge in terms of sluggish charge transfer kinetic and ultra-short charge lifetime compared with nanoparticulate counterparts, thereby rendering maneuvering charge transfer of TMCs QDs a tough issue. We herein conceptually unlock the unanticipated charge transport capability of solid-state non-conductive poly(diallyl dimethylammonium chloride) (PDDA) for constructing cascade charge transfer pathway over self-assembled wide bandgap semiconductors (WBS)/PDDA/TMCs QDs multilayered heterostructures, by which unidirectional and accelerated electron transfer from TMCs QDs to WBS support mediums was spontaneously activated, markedly boosting the charge separation/migration efficiency. The integrated roles of such ultrathin insulating PDDA intermediate layer as simultaneous surface charge modifying agent and interfacial charge transfer mediator have been evidenced to be universal. The unexpected electron-withdrawing capability of ultrathin PDDA layer endows WBS (SnO2, TiO2)@PDDA@TMCs (CdSe, CdS) QDs heterostructures with significantly enhanced net efficiency of photoactivities toward selective anaerobic reduction of nitroaromatics to amino derivatives under visible light irradiation. Our work would feature a promising scope for rational design of multifarious novel insulating polymers-based photosystems for solar energy conversion.
