15164-44-0Relevant articles and documents
N-Doped carbon encapsulated molybdenum carbide as an efficient catalyst for oxidant-free dehydrogenation of alcohols
Leng, Yan,Li, Jingjing,Zhang, Chenjun,Jiang, Pingping,Li, Yue,Jiang, Yuchen,Du, Shengyu
, p. 17580 - 17588 (2017)
We report molybdenum carbide (Mo2C) encapsulated in N-doped carbon as an efficient and stable catalyst for oxidant-free dehydrogenation of alcohols, prepared by anion exchange of H3PMo12O40 (PMo) with an ionic copolymer (DIM-AN) of dicationic imidazole ionic liquid and acrylonitrile, followed by a two-step carbonization at 400 °C in air and 800 °C in Ar. The synthesized catalyst (PMo@DIM-AN400/800) exhibits outstanding catalytic activity and selectivity for dehydrogenation of various alcohols under oxidant-free conditions and can be steadily reused at least five times for dehydrogenation of benzyl alcohol without changing its crystalline structure. The characterizations and comparative experimental results demonstrate that the active sites for dehydrogenation stem from the Mo2C, as well as the abundant N atoms in the carbon shell, which contribute to the enhancement of catalytic performance. The strategy for the preparation of such N-doped carbon encapsulated Mo2C using polyoxometalate-based ionic hybrids as precursors may open up new opportunities for exploring more transition-metal carbides for more catalytic applications.
Copper(II) Complexes of 2,2:6,2-Terpyridine Derivatives for Catalytic Aerobic Alcohol Oxidations - Observation of Mixed-Valence CuICuII Assembles
Zhang, Guoqi,Liu,Yang, Chengxiong,Li, Li,Golen, James A.,Rheingold, Arnold L.
, p. 939 - 947 (2015)
The reactions of copper(II) salts with simple terpyridine (tpy) ligands gave mononuclear monoligand complexes 1-3, of which two new structures have been characterized by X-ray crystallography. These complexes were applied as catalysts for the oxidation of benzylic alcohol to benzaldehyde in air in the presence of the radical 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO). Copper complexes 1 and 2 are efficient catalysts for the reactions in water at 70 C with 4-dimethylaminopyridine (DMAP) as an extra base. The influence of TEMPO on the formation of new reactive intermediates during the catalytic reactions was tentatively investigated by introducing TEMPO into the reaction solutions of tpy derivatives with copper dichloride. Two new complexes with interesting solid-state structures resulting from these reactions have been isolated and characterized. The coordination reactions in the presence of TEMPO led to new mixed-valence CuICuII supramolecular assembles (4 and 5), although they adopt either discrete complex or 1D polymeric structures. Further catalytic studies indicated that the mixed-valence assembles 4 and 5 displayed higher catalytic activity than those of the mononuclear complexes under milder conditions. The relationship between the molecular structures of diverse copper complexes and their reactivity is discussed on the basis of the results obtained.
Practical and efficient ipso-iodination of arylboronic acids via KF/I2 system
Tramutola, Francesco,Chiummiento, Lucia,Funicello, Maria,Lupattelli, Paolo
, p. 1122 - 1123 (2015)
A facile and effective iododeboronation of variously substituted aryl and heteroarylboronic acids through activation and subsequent ipso-introduction of iodine is presented. The use of KF and I2 at 80 °C in 1,4-dioxane furnishes iodinated compounds in high yields.
Ti3C2/TiO2 nanowires with excellent photocatalytic performance for selective oxidation of aromatic alcohols to aldehydes
Xu, Chong,Yang, Fan,Deng, Bijian,Zhuang, Yue,Li, Dingyao,Liu, Baocheng,Yang, Wang,Li, Yongfeng
, p. 1 - 12 (2020)
The Ti3C2/TiO2 nanowires photocatalyst is synthesized by in situ growth through a facile hydrothermal method and mild chemical processes for the first time. The Ti3C2/TiO2-0.7 exhibits high photocatalytic activity for selective oxidation of aromatic alcohols to aldehydes under visible light irradiation. The 92% benzyl alcohol conversion and almost 99% selectivity is observed for the Ti3C2/TiO2-0.7 photocatalyst, higher than that of P25 and TiO2 nanowires. Results reveal that the photocatalytic activity of this photocatalyst is mainly attributed to the introduction of Ti3C2, which results in the narrowed energy band gap by altering the position of CB and VB of TiO2 and the enhanced light-harvesting ability. In our design, a Schottky barrier is established between Ti3C2 and TiO2 nanowires to improve the separation efficiency of photogenerated electrons and holes. Significantly, the feasible reaction mechanism of Ti3C2/TiO2 nanowires photocatalyst under visible light is proposed.
Synthesis of a single-molecule nanotruck
Sasaki, Takashi,Morin, Jean-Fran?ois,Lu, Meng,Tour, James M.
, p. 5817 - 5820 (2007)
We report the synthesis of a new nanovehicle, a porphyrin-based nanotruck. The porphyrin inner core was designed for possible transportation of metals and small molecules across a surface.
Acetylenic Scaffolding with Subphthalocyanines
Gotfredsen, Henrik,Jevric, Martyn,Kadziola, Anders,Nielsen, Mogens Brondsted
, p. 17 - 21 (2016)
A new boron subphthalocyanine (SubPc) derivative with a terminal alkyne substituent on the central boron atom was prepared by substitution of a triflate at the boron atom with but-3-yn-1-ol. This compound was shown to be a versatile building block for metal-catalyzed coupling reactions, such as modified Glaser-Hay, Cadiot-Chodkiewicz, and Sonogashira reactions as well as the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). For example, metal-catalyzed reactions provided access to a SubPc dimer containing a butadiyne bridging unit, two different SubPc-fullerene dyads as well as two cross-conjugated SubPc-tetraethynylethene (TEE) scaffolds. These TEEs containing two silyl-protected alkyne units are potential building blocks for further acetylenic scaffolding. The work shows how the axial position is post-functionalized in steps not involving a substitution reaction at the central boron atom, which is otherwise often used as the terminal step in axial functionalization of SubPcs.
Chiral tetranuclear and dinuclear copper(ii) complexes for TEMPO-mediated aerobic oxidation of alcohols: Are four metal centres better than two?
Zhang, Guoqi,Proni, Gloria,Zhao, Sherry,Constable, Edwin C.,Housecroft, Catherine E.,Neuburger, Markus,Zampese, Jennifer A.
, p. 12313 - 12320 (2014)
The one-pot reaction of 3,5-di-tert-butyl-2-hydroxybenzaldehyde, (R)-2-aminoglycinol and Cu(OAc)2·2H2O in a 1:1:1 ratio in the presence of triethylamine led to the isolation of X-ray quality crystals of the chiral complex (R)-1 in high yield. The single crystal structure of (R)-1 reveals a tetranuclear copper(ii) complex that contains a {Cu 4(μ-O)2(μ3-O)2N 4O4} core. A reaction using (1S,2R)-2-amino-1,2- diphenylethanol as precursor under the same conditions generated the chiral complex (S,R)-2; its structure was determined by single crystal X-ray crystallography and was found to contain a {Cu2(μ-O) 2N2O2} core. Both (R)-1 and (S,R)-2 have been used for catalytic aerobic oxidation of benzylic alcohols in combination with the TEMPO (2,2,6,6-tetramethylpiperidinyl-1-oxyl) radical. (R)-1 selectively catalyses the conversion of various aromatic primary alcohols to the corresponding aldehydes with high yields (99%) and TONs (770) in the air, while (S,R)-2 exhibits less promising catalytic performance under the same reaction conditions. The role of the cluster structures in (R)-1 and (S,R)-2 in controlling the reactivity towards aerobic oxidation reactions is discussed.
Facile aromatic finkelstein iodination (AFI) reaction in 1,3-dimethyl-2-imidazolidinone (DMI)
Yamashita, Ken-Ichi,Tsuboi, Michihiro,Asano, Motoko S.,Sugiura, Ken-Ichi
, p. 170 - 175 (2012)
In this communication, we report the superior role of 1,3-dimethyl-2- imidazolidinone (DMI) as a solvent for aromatic Finkelstein iodination (AFI), the conversion of aryl bromides to aryl iodides. DMI accelerates the reaction rate and affords product(s) that could not be prepared using previous methods. Our findings for AFI avoid the use of toxic solvents such as N,N-dimethylformamide and hexamethylphosphoramide. Taylor & Francis Group, LLC.
Photo-tunable oxidation of toluene and its derivatives catalyzed by TBATB
Mardani, Atefeh,Kazemi, Foad,Kaboudin, Babak
, (2021/05/04)
In this report, tetrabutylammonium tribromide (TBATB) was introduced as an efficient visible light active catalyst to carry out the aerobic oxidation of toluene, its derivatives, and some of methyl arenes to benzaldehydes, benzoic acids and ketones in good to high yields. All the oxidation reactions were performed under mild conditions using oxygen as a green oxidant, a catalytic amount of TBATB under blue (460 nm), royal blue (430 nm), and violet LED (400 nm) irradiation. It was found that the reactions selectivity was significantly affected by changing the solvent (from CH3CN to EtOAc) and LED wavelength (from blue to violet). In the following, our mechanistic studies revealed that the visible light oxidation of toluenes and methyl arenes over TBATB could be following a benzyl peroxy radical intermediate.
METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
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Paragraph 0071; 0077, (2021/07/10)
A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method includes the steps of: (A) providing a compound (I) with an unsaturated double bond, a trifluoromethyl-containing reagent, and a catalyst; wherein, the catalyst is represented by Formula (II): M(O)mL1yL2z??(II);wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and(B) mixing the compound with an unsaturated double bond and the trifluoromethyl-containing reagent to perform an oxidative cleavage of the compound with the unsaturated double bond by using the catalyst in air or under oxygen atmosphere condition to obtain a compound represented by Formula (III):
Merging N-Hydroxyphthalimide into Metal-Organic Frameworks for Highly Efficient and Environmentally Benign Aerobic Oxidation
Wang, Man,Liang, Gan,Wang, Yunhao,Fan, Tao,Yuan, Baoling,Liu, Mingxian,Yin, Ying,Li, Liangchun
supporting information, p. 9674 - 9685 (2021/06/09)
Two highly efficient metal-organic framework catalysts TJU-68-NHPI and TJU-68-NDHPI have been successfully synthesized through solvothermal reactions of which the frameworks are merged with N-hydroxyphthalimide (NHPI) units, resulting in the decoration of pore surfaces with highly active nitroxyl catalytic sites. When t-butyl nitrite (TBN) is used as co-catalyst, the as-synthesized MOFs are demonstrated to be highly efficient and recyclable catalysts for a novel three-phase heterogeneous oxidation of activated C?H bond of primary and secondary alcohols, and benzyl compounds under mild conditions. Based on the high efficiency and selectivity, an environmentally benign system with good sustainability, mild conditions, simple work-up procedure has been established for practical oxidation of a wide range of substrates.
