939-23-1Relevant articles and documents
Re(VII) complex of N-fused tetraphenylporphyrin
Toganoh, Motoki,Ikeda, Shinya,Furuta, Hiroyuki
, p. 4589 - 4591 (2005)
By treatment of N-fused tetraphenylporphyrin rhenium(I) tricarbonyl complex with trimethylamine N-oxide, oxidation of the metal center proceeded to afford N-fused tetraphenylporphyrin rhenium(VII) trioxo complex, which was quite stable against air, light and heat. The Royal Society of Chemistry 2005.
Cobalt-catalyzed cross-coupling of nitrogen-containing heterocyclic phosphonium salts with arylmagnesium reagents
Cui, Yan-Ying,Na, Jin-He,Guo, Meng-Meng,Huang, Jie-Ying,Chu, Xue-Qiang,Rao, Weidong,Shen, Zhi-Liang
supporting information, (2022/02/16)
Cobalt-catalyzed cross-couplings of nitrogen-containing heterocyclic phosphonium salts with arylmagnesium halides proceeded efficiently with the aid of cobalt(II) catalyst and copper(I) salt in tetrahydrofuran at ambient temperature, producing the desired
Highly Chemoselective Deoxygenation of N-Heterocyclic N-Oxides Using Hantzsch Esters as Mild Reducing Agents
An, Ju Hyeon,Kim, Kyu Dong,Lee, Jun Hee
supporting information, p. 2876 - 2894 (2021/02/01)
Herein, we disclose a highly chemoselective room-temperature deoxygenation method applicable to various functionalized N-heterocyclic N-oxides via visible light-mediated metallaphotoredox catalysis using Hantzsch esters as the sole stoichiometric reductant. Despite the feasibility of catalyst-free conditions, most of these deoxygenations can be completed within a few minutes using only a tiny amount of a catalyst. This technology also allows for multigram-scale reactions even with an extremely low catalyst loading of 0.01 mol %. The scope of this scalable and operationally convenient protocol encompasses a wide range of functional groups, such as amides, carbamates, esters, ketones, nitrile groups, nitro groups, and halogens, which provide access to the corresponding deoxygenated N-heterocycles in good to excellent yields (an average of an 86.8% yield for a total of 45 examples).
Metal-Free Deoxygenation of Amine N-Oxides: Synthetic and Mechanistic Studies
Lecroq, William,Schleinitz, Jules,Billoue, Mallaury,Perfetto, Anna,Gaumont, Annie-Claude,Lalevée, Jacques,Ciofini, Ilaria,Grimaud, Laurence,Lakhdar, Sami
, p. 1237 - 1242 (2021/06/01)
We report herein an unprecedented combination of light and P(III)/P(V) redox cycling for the efficient deoxygenation of aromatic amine N-oxides. Moreover, we discovered that a large variety of aliphatic amine N-oxides can easily be deoxygenated by using only phenylsilane. These practically simple approaches proceed well under metal-free conditions, tolerate many functionalities and are highly chemoselective. Combined experimental and computational studies enabled a deep understanding of factors controlling the reactivity of both aromatic and aliphatic amine N-oxides.
Inhibition of (dppf)nickel-catalysed Suzuki-Miyaura cross-coupling reactions by α-halo-N-heterocycles
Burton, Paul M.,Cooper, Alasdair K.,Donohoe, William,Greaves, Megan E.,Kennedy, Alan R.,Nelson, David J.,Ronson, Thomas O.
, p. 14074 - 14082 (2021/11/12)
A nickel/dppf catalyst system was found to successfully achieve the Suzuki-Miyaura cross-coupling reactions of 3- and 4-chloropyridine and of 6-chloroquinoline but not of 2-chloropyridine or of other α-halo-N-heterocycles. Further investigations revealed that chloropyridines undergo rapid oxidative addition to [Ni(COD)(dppf)] but that α-halo-N-heterocycles lead to the formation of stable dimeric nickel species that are catalytically inactive in Suzuki-Miyaura cross-coupling reactions. However, the corresponding Kumada-Tamao-Corriu reactions all proceed readily, which is attributed to more rapid transmetalation of Grignard reagents.
Palladium nanoparticles encapsulated in polyimide nanofibers: An efficient and recyclable catalyst for coupling reaction
Du, Yijun,Gou, Faliang,Gao, Danning,Liu, Zhifeng,Shao, Linjun,Qi, Chenze
, (2021/09/15)
In this study, palladium-encapsulated poly(amic acid) (Pd@PAA) nanofibers were prepared by electrospinning, followed by thermal imidization to synthesize palladium-encapsulated polyimide (Pd@PI) nanofibers. Scanning electron microscopy (SEM) images confirmed the preparation of uniform and smooth Pd@PAA and Pd@PI nanofibers. Thermogravimetric analysis (TGA) results reveal that the Pd@PI nanofibers possessed excellent thermal stability. The dispersion of palladium nanoparticles in the polyimide nanofibers was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The catalysis results show that this Pd@PI fibrous catalyst was very efficient to catalyze the cross-coupling reactions of aromatic iodides with n-butyl acrylate (Heck reaction) or phenylboronic acid derivatives (Suzuki reaction) to afford the desired products in good to excellent yields. Moreover, the Pd@PI catalyst could be easily separated and recovered from the reaction mixture by simple filtration due to the regular fibrous structure and reused for 10 times for both Heck and Suzuki reactions without obvious loss of its initial catalytic activity. Thus, the Pd@PI nanofiber catalyst holds great potential in chemical industry in terms of its excellent catalytic activity and stability.
Efficient and Economical Preparation of Hypercrosslinked Polymers-palladium Based on Schiff Base as Recyclable Catalyst for Suzuki-Miyaura Reactions
Gao, Xiyue,Lin, Hongwei,Liu, Shasha,Luo, Qionglin,Ouyang, Yuejun,Xiang, Bailin,Xiang, Dexuan,Yao, Huan,Zhang, Li
supporting information, p. 1879 - 1882 (2021/10/29)
A novel hypercrosslinked polymer (HCP) was prepared via Friedel-Crafts alkylation reaction of Schiff base with benzene and formaldehyde dimethyl acetal (FDA) promoted by FeCl3. The HCP was then metalated with Pd(II) to form heterogeneous catalyst. The protocol featured low cost, mild conditions, readily available materials, easy separation and high yield. Physicochemical methods, including IR, N2 sorption, ICP, TGA, XPS, SEM, EDX, and TEM, were used to characterize the catalyst structure and composition. The results reveal that the heterogeneous catalyst possesses high specific surface area, large pore volume, good chemical and thermal stability, and highly dispersed palladium. The heterogeneous catalysts were applied in Suzuki-Miyaura coupling reaction to evaluate their catalytic performance. The experiments reflected that the HCPs-Pd(OAc)2 was an efficient catalyst for Suzuki-Miyaura reactions with the yield of biaryl up to 99%, while the TON could reach 2250. The reusability test showed the catalyst was easily recovered and reused for at least six times without obvious decrease in activity.
Immobilization of a Pd(ii)-containing N-heterocyclic carbene ligand on porous organic polymers: efficient and recyclable catalysts for Suzuki-Miyaura reactions
Gao, Xiyue,Lin, Hongwei,Liu, Cijie,Luo, Qionglin,Ouyang, Yuejun,Xiang, Bailin,Xiang, Dexuan,Yao, Huan,Zhou, Nonglin
, p. 3676 - 3680 (2021/06/17)
Palladium coordinated with N-heterocyclic carbene-functionalized porous organic polymers (Pd@POPs) was successfully preparedviaScholl coupling reaction and a successive immobilization method. The protocol features simple reaction conditions, easy separation, high yield and low cost. The structure and composition of Pd@POPs were characterized by N2sorption, TGA, FT-IR, SEM, EDX, TEM, XPS and ICP. Then the obtained heterogeneous catalysts were applied in Suzuki-Miyaura coupling reaction to evaluate their catalytic performance. The Pd@POPs displayed high catalytic activity for the Suzuki-Miyaura coupling reaction in an EtOH/H2O solvent. A 0.03 mol% Pd loading was sufficient for the reaction with a high turnover number (TON) of 3220. Moreover, the catalyst was easily recovered and reused for at least six consecutive cycles without obvious loss of its initial activity.
Polydopamine-Encapsulated Dendritic Organosilica Nanoparticles as Amphiphilic Platforms for Highly Efficient Heterogeneous Catalysis in Water
Gao, Jing,Guo, Na,Jiang, Yanjun,Liu, Guanhua,Liu, Pengbo,Liu, Yunting,Wang, Zihan,Zhang, Lei
supporting information, p. 1975 - 1982 (2021/06/09)
Aqueous heterogeneous catalysis is a green, sustainable catalytic process that attracts increasing attention, but it often suffers from poor mass transfer, substrate adsorption and catalyst dispersion. Herein, we synthesized a type of amphiphilic core-shell catalysts with a hydrophilic polydopamine (PDA) shell and a hydrophobic dendritic organosilica nanoparticle (DON) core for heterogeneous catalysis in water. The hydrophilic shell allowed the catalyst dispersing well in water, and the hydrophobic core facilitated the absorption of organic reactants. The hierarchical core-shell structure facilitated rational arrangement of the location of catalytic species to match the reaction sequence. The obtained metal, enzyme and metal-enzyme amphiphilic catalysts demonstrated improved stability, selectivity and activity in aqueous reactions, including Pd-catalyzed cross-couplings (Suzuki, Liebeskind-Srogl, Heck and Sonogashira), enzymatic enantioselective reduction, chemoenzymatic cascade synthesis of chiral compounds and chemoenzymatic cascade degradation of organophosphates. The amphiphilic catalysts could be easily in situ recovered, and their high catalytic performance was sustained for five cycles.
Nickel-catalyzed heterocyclic phosphonium salt and aryl bromide direct reduction cross-coupling method and product
-
Paragraph 0034-0040; 0055-0077, (2021/09/15)
The invention discloses a nickel-catalyzed heterocyclic phosphonium salt and aryl bromide direct reduction cross-coupling method and a product, and the method comprises the following steps: in a nitrogen atmosphere, heating a mixture of magnesium chips and lithium chloride; cooling the mixture to room temperature, and adding an ultra-dry solvent into the mixture; then respectively adding a phosphonium salt compound, a catalyst, a ligand and aryl bromide, and stirring to react; and quenching, washing, extracting and drying the reaction product, and separating by column chromatography to obtain the arylated pyridine or diazine compound. The preparation method has the characteristics of mild reaction conditions, simple post-treatment, green steps, low pollution, high economic benefits and the like.
