148-86-7Relevant articles and documents
Palladium supported on functionalized mesoporous silica as an efficient catalyst for Suzuki-Miyaura coupling reaction
Zhang, Guoheng,Wang, Peiyu,Wei, Xiufang
, p. 1188 - 1194 (2013)
Mesoporous SBA-15 was modified with organic functional groups by co-condensation method. The functionalized mesoporous silica can be loaded with palladium and the resulting material used as a catalyst for the Suzuki-Miyaura coupling reactions. Highly dispersed and uniform palladium nanoparticles could be detected using transmission electron microscopy. The Pd-SBA-15 nanocomposite with controlled molar ratio of amino groups to palladium exhibits an excellent catalytic activity and low Pd leaching for the Suzuki-Miyaura coupling reaction. The catalyst can also be reused at least six recycles in air with only a minor loss of activity. Graphical Abstract: Mesoporous SBA-15 was modified with organic functional groups by co-condensation method. The functionalized mesoporous silica can be loaded with palladium and the resulting material used as a catalyst for the Suzuki-Miyaura coupling reactions. Highly dispersed and uniform palladium nanoparticles could be detected using transmission electron microscopy. The Pd-SBA-15 nanocomposite with controlled molar ratio of amino groups to palladium exhibits an excellent catalytic activity and low Pd leaching for the Suzuki-Miyaura coupling reaction. The catalyst can also be reused at least six recycles in air with only a minor loss of activity.[Figure not available: see fulltext.]
D-Glucosamine based-phosphine for Suzuki-Miyaura cross-coupling reactions in the supported aqueous phase catalysis system
Wójcik, Karolina,Goux-Henry, Catherine,Andrioletti, Bruno,Micha? Pietrusiewicz,Framery, Eric
, p. 5602 - 5604 (2012)
A d-glucosamine-based phosphine/Pd(OAc)2 complex has been applied to the Suzuki-Miyaura coupling reaction of aryl bromides with arylboronic acids using the supported aqueous phase catalysis, SAPC, concept. The recyclability of the catalyst was investigated and revealed a very high activity during the 4 runs.
A graphdiyne-based carbon material for electroless deposition and stabilization of sub-nanometric Pd catalysts with extremely high catalytic activity
Yang, Liang-Liang,Wang, Hong-Juan,Wang, Juan,Li, Yu,Zhang, Wen,Lu, Tong-Bu
, p. 13142 - 13148 (2019)
The development of sub-nanometric metal particles (1 nm) as advanced heterogeneous catalysts has received considerable interest due to their outstanding catalytic performance, while the synthesis and stabilization of sub-nanometric catalysts (SNCs) without using additional surface capping agents remains a challenge. Herein, we report the synthesis of novel three-dimensional pyrenyl graphdiyne (Pyr-GDY) ultrafine nanofibers (3-10 nm), which can serve as an ideal substrate for electroless deposition and stabilization of Pd SNCs through the terminal uncoupled acetenyl groups in Pyr-GDY, with an average Pd particle size of only 0.83 nm. The as-synthesized Pd/Pyr-GDY composite shows extremely high catalytic activities for the reduction of nitroarenes to arylamines and Suzuki coupling reactions, 300 and 25 times higher than those of commercial Pd/C, respectively. The outstanding catalytic performance can be ascribed to the sub-nanometric Pd particles with a "clean surface", and the unique three-dimensional network structure of Pyr-GDY, being favorable for rapid mass transfer. Our result provides an ideal carbon material for electroless deposition and stabilization of other SNCs with a "clean surface", which will display outstanding catalytic activity for various catalytic reactions.
Direct Acetoxylation of Arenes
Hong Nguyen, Thi Anh,Hou, Duen-Ren
supporting information, p. 8127 - 8131 (2021/08/23)
Acetoxylation of arenes is an important reaction and an unmet need in chemistry. We report a metal-free, direct acetoxylation reaction using sodium nitrate under an anhydrous environment of trifluoroacetic acid, acetic acid, and acetic anhydride. Arenes (31 examples), with oxidation potentials (Eox, in V vs SCE) lower than benzene (2.48 V), were acetoxylated with good yields and regioselectivity. A stepwise, single electron-transfer mechanism is proposed.
Rhodium-Catalyzed Carbonylative Coupling of Alkyl Halides with Phenols under Low CO Pressure
Ai, Han-Jun,Li, Chong-Liang,Wang, Hai,Wu, Xiao-Feng
, p. 5147 - 5152 (2020/05/27)
A rhodium-catalyzed carbonylative transformation of alkyl halides under low pressure of CO has been developed. This robust catalyst system allows using phenols as the carbonylative coupling partner and, meanwhile, exhibits high functional group tolerance and good chemoselectivity. Substrates even with a large steric hindrance group or multiple reaction sites can be selectively converted into the desired products in good to excellent yields. A gram-scale experiment was performed and delivered an almost quantitative amount of the product. Control experiments were performed as well, and a possible reaction mechanism is proposed.
Synthesis and anti-inflammatory activity of 2-oxo-2H-chromenyl and 2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates
Bhimapaka, China Raju,Karri, Shailaja,Kuncha, Madhusudana,Kurma, Siva Hariprasad,Sistla, Ramakrishna
, (2020/06/22)
Cycloaddition reaction of 4-chloro-2-oxo-2H-chromene-3-carbaldehydes (3a-g) and 4-chloro-2H-chromene-3-carbaldehydes (7a-h) with activated alkynes (4a-b) provided the 2-oxo-2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates (5a-n) and 2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates (8a-p). All the prepared compounds were screened for anti-inflammatory activity. In vitro anti-inflammatory activity data demonstrated that the compounds 5g, 5i, 5k-l and 8f are effective among the tested compounds against TNF-α (1.108 ± 0.002, 0.423 ± 0.022, 0.047 ± 0.001, 0.070 ± 0.002 and 0.142 ± 0.001 μM) in comparison with standard compound Prednisolone (0.033 ± 0.002 μM). Based on in vitro results, three compounds (5i, 5k and 8f) have been selected for in vivo experiments and these compounds are identified as better compounds with respect to anti-inflammatory activity in LPS induced mice model. Compound 5i was identified as potent and showed significant reduction in TNF-α and IL-6.
Visible-Light-Induced [4+2] Annulation of Thiophenes and Alkynes to Construct Benzene Rings
Song, Chunlan,Dong, Xin,Wang, Zhongjie,Liu, Kun,Chiang, Chien-Wei,Lei, Aiwen
supporting information, p. 12206 - 12210 (2019/07/31)
The [4+2] annulation represents an elegant and versatile synthetic protocol for the construction of benzene rings. Herein, a strategy for visible-light induced [4+2] annulation of thiophenes and alkynes, to afford benzene rings, is presented. Under simple and mild reaction conditions, the ready availability and structural diversity of thiophenes and alkynes permit the facile synthesis of several substituted aromatic rings. Valuable drugs and amino acids are also well tolerated. Moreover, DFT calculations explain the high regioselectivity of the reaction.
Metal-Free and Redox-Neutral Conversion of Organotrifluoroborates into Radicals Enabled by Visible Light
Liu, Wenbo,Liu, Peng,Lv, Leiyang,Li, Chao-Jun
, p. 13499 - 13503 (2018/09/25)
Converting organoboron compounds into the corresponding radicals has broad synthetic applications in organic chemistry. To achieve these transformations, various strong oxidants such as Mn(OAc)3, AgNO3/K2S2O8, and Cu(OAc)2, in stoichiometric amounts are required, proceeding by a single-electron transfer mechanism. Established herein is a distinct strategy for generating both aryl and alkyl radicals from organotrifluoroborates through an SH2 process. This strategy is enabled by using water as the solvent, visible light as the energy input, and diacetyl as the promoter in the absence of any metal catalyst or redox reagent, thereby eliminating metal waste. To demonstrate its synthetic utility, an efficient acetylation to prepare valuable aryl (alkyl) methyl ketones is described and applications to construct C?C, C?I, C?Br, and C?S bonds are also feasible. Experimental evidence suggests that triplet diacetyl serves as the key intermediate in this process.
A PdII Carbene Complex with Anthracene Side-Arms for π-Stacking on Reduced Graphene Oxide (rGO): Activity towards Undirected C–H Oxygenation of Arenes
Majeed, Maitham H.,Shayesteh, Payam,Persson, Axel R.,Wallenberg, L. Reine,Schnadt, Joachim,Wendt, Ola F.
supporting information, p. 4742 - 4746 (2018/11/27)
An N-heterocyclic carbene palladium(II) complex containing two anthracene side arms was immobilized on the surface of reduced graphene oxide (rGO) by π-stacking. The activity of the homogeneous analogue and the supported complex in undirected C–H acetoxylation reaction of arenes was studied. The results show that the catalytic efficiency in acetoxylation of benzene is improved in the immobilized materials compared to the homogeneous analogue. According to XPS analysis, the immobilized catalyst maintains the original oxidation state of PdII after the catalytic reaction.
C-C cross-coupling reactions by palladium on barium and potassium polyoxotungstate supports
Karume,Tebandeke,Mbabazi,Ssekaalo,Wendt
, p. 2357 - 2360 (2018/09/09)
A heterogeneous catalyst system for Suzuki and Heck coupling reactions was developed using polyoxometalates as supports for palladium. The catalyst system was synthesized in a one step process using sodium phosphotungstate and palladium acetate. We used the supported catalyst in organic media without the need for special ligands. Substantial activity was observed after several recycles. The catalyst showed high product selectivity with yields up to > 95 % in both Suzuki and Heck reactions.
