626-64-2Relevant articles and documents
Fullerene soot and a fullerene nanodispersion as recyclable heterogeneous off-the-shelf photocatalysts
Jozeliūnait?, Augustina,Val?eckas, Domantas,Orentas, Edvinas
, p. 4104 - 4111 (2021/02/02)
Metal-free heterogeneous photocatalysis, which requires no prior catalyst immobilization or chemical modification and can operate in green solvents, represents a highly-sought after, yet currently still underdeveloped, synthetic method. In this report we present a comparative study which aims to evaluate the use of unmodified fullerene soot and a fullerene nanodispersion as non-soluble and quasi-soluble carbon-based photocatalysts, respectively, for sulfide oxidation and other transformations using oxygen as an oxidant in ethanol. A wide range of sulfoxides were successfully prepared with good yields and chemoselectivity using a very low catalyst loading. The fullerene soot photocatalyst is easily recovered and shows excellent stability of the catalytic properties. The reaction was shown to proceed via a singlet oxygen pathway and has a high selectivity for aliphatic sulfides, whereas the oxidation of thioanisoles can be accomplished using an amine mediated electron transfer mechanism. The applicability of the fullerene nanodispersion as a general purpose photocatalyst was demonstrated in radical cyclization, boronic acid oxidation and imine formation reactions.
Isotruxene-based porous polymers as efficient and recyclable photocatalysts for visible-light induced metal-free oxidative organic transformations
Zhang, Haowen,Zhang, Xiao,Zheng, Ying,Zhou, Cen
supporting information, p. 8878 - 8885 (2021/11/27)
Two new isotruxene-based porous polymers were prepared and demonstrated to be highly efficient, metal-free heterogeneous photocatalysts for oxidative transformations using air as the mild oxidant under visible-light irradiation. Both catalysts show excellent recyclability. In addition, the reactions can be performed in water, further indicating the greenness of this method. This journal is
Coordination Polymers as a Functional Material for the Selective Molecular Recognition of Nitroaromatics and ipso-Hydroxylation of Arylboronic Acids
Bhasin, K. K.,Husain, Ahmad,Kumar, Girijesh,Rani, Pooja
, (2021/12/06)
We report the synthesis and structural characterization of two coordination polymers (CPs), namely; [{Zn(L)(DMF)4} ? 2BF4]α (1) and [{Cd(L)2(Cl)2} ? 2H2O]α (2) (where L=N2,N6-di(pyridin-4-yl)naphthalene-2,6-dicarboxamide). Crystal packing of 1 reveals the existence of channels running along the b- and c-axis filled by the ligated DMF and lattice anions, respectively. Whereas, crystal packing of 2 reveals that the metallacycles of each 1D chain are intercalating into the groove of adjacent metallacycles resulting in the stacking of 1D loop-chains to form a sheet-like architecture. In addition, both 1 and 2 were exploited as multifunctional materials for the detection of nitroaromatic compounds (NACs) as well as a catalyst in the ipso-hydroxylation of aryl/heteroarylboronic acids. Remarkably, 1 and 2 showed high fluorescence stability in an aqueous medium and displayed a maximum 88% and 97% quenching efficiency for 4-NPH, respectively among all the investigated NACs. The mechanistic investigation of NACs recognition suggested that the fluorescence quenching occurred via electron as well as energy transfer process. Furthermore, the ipso-hydroxylation of aryl/heteroarylboronic acids in presence of 1 and 2 gave up to 99% desired product yield within 15 min in our established protocol. In both cases, 1 and 2 are recyclable upto five cycles without any significant loss in their efficiency.
Application of Electron-Rich Covalent Organic Frameworks COF-JLU25 for Photocatalytic Aerobic Oxidative Hydroxylation of Arylboronic Acids to Phenols
Xiao, Guangjun,Li, Wenqian,Chen, Tao,Hu, Wei-Bo,Yang, Hui,Liu, Yahu A.,Wen, Ke
supporting information, p. 3986 - 3991 (2021/03/29)
Visible-light-driven organic reactions are environmentally friendly green chemical transformations among which photosynthetic oxidative hydroxylation of arylboronic acids to phenols has attracted increasing research interest during the very recent years. Given the efficiency and reusability of heterogeneous catalysts, COF-JLU25, an electron-rich COF-based photocatalyst constructed by integrating electron-donating blocks 1,3,6,8-tetrakis(4-aminophenyl)pyrene (PyTA) and 4-[4-(4-formylmethyl)-2,5-dimethoxyphenyl] benzaldehyde (TpDA), was selected as a photocatalyst for the oxidative hydroxylation of arylboronic acids. In our studies, COF-JLU25 demonstrated excellent photocatalytic activity with high efficiency, robust reusability, and low catalyst loading, showcasing an application potential of previously underexplored COF-based photocatalyst composed solely of electron-rich units.
Transforming a Fluorochrome to an Efficient Photocatalyst for Oxidative Hydroxylation: A Supramolecular Dimerization Strategy Based on Host-Enhanced Charge Transfer
Tang, Bohan,Xu, Weiquan,Xu, Jiang-Fei,Zhang, Xi
supporting information, p. 9384 - 9388 (2021/03/22)
The development of non-covalent synthetic strategy to fabricate efficient photocatalysts is of great importance in theranostic and organic materials. Herein, a fluorochrome N,N′-dimethyl 2,5-bis(4-pyridinium)thiazolo[5,4-d]thiazolediiodide (MPT) was transformed into an efficient photocatalyst through supramolecular dimerization in the cavity of cucurbit[8]uril (CB[8]). The host-enhanced charge transfer interaction within the supramolecular dimer 2MPT-CB[8] dramatically promoted intersystem crossing to produce triplet. In addition, the staggered conformation of 2MPT-CB[8] facilitated the energy transfer and electron transfer of the triplet. As a result, 2MPT-CB[8] could serve as a high-efficiency photocatalyst for the oxidative hydroxylation of arylboronic acids. This supramolecular dimerization strategy enriches the supramolecular engineering of functional π-systems. It is anticipated that this strategy can be extended to fabricate various π-systems with tailor-made functions.
Visible-light-promoted aerobic oxidative hydroxylation of arylboronic acids in water by hydrophilic organic semiconductor
Yu, Kunyi,Zhang, Hanjie,Sheng, Yuqiang,Zhu, Yongfa
supporting information, (2020/06/23)
A green and sustainable catalytic system was developed based on perylenediimide (PDI) organic semiconductor for the aerobic oxidative hydroxylation of arylboronic acids in aqueous solution with visible light. By using PDI-SN, a hydrophilic organic semiconductor, which can activate oxygen to produce superoxide radicals in aqueous solution, this reaction proceeds under ambient conditions: water as the solvent and air as the oxidant, giving various phenols as products with high yields. In contrast to methods using organic solvents, this novel process has the potential of green industrial application.
Nickel-catalyzed oxidative hydroxylation of arylboronic acid: Ni(HBTC)BPY MOF as an efficient and ligand-free catalyst to access phenolic motifs
Latha, Ganesapandian,Devarajan, Nainamalai,Karthik, Murugan,Suresh, Palaniswamy
, (2020/01/08)
A straightforward and mild oxidative ipso-hydroxylation of arylboronic acids has been achieved using a simple and non-noble metal, nickel-based reusable heterogeneous catalyst Ni(HBTC)BPY MOF (HBTC = benzene-1,3,5-tricarboxylate, BPY = 4,4′-bipyridine) in the presence of benign hydrogen peroxide as an oxidant under ambient reaction condition. The Ni(HBTC)BPY MOF exhibits excellent catalytic activity towards the formation of phenols from diverse arylboronic acids within short time and can be reused up to five times without any notable loss in its activity as well as shown high functional group tolerance even in the presence of sensitive functionalities and useful to achieve hydroxyl group in heterocycles.
Photoinduced Hydroxylation of Organic Halides under Mild Conditions
Cai, Yue-Ming,Xu, Yu-Ting,Zhang, Xin,Gao, Wen-Xia,Huang, Xiao-Bo,Zhou, Yun-Bing,Liu, Miao-Chang,Wu, Hua-Yue
supporting information, p. 8479 - 8484 (2019/10/16)
Presented in this paper is photoinduced hydroxylation of organic halides, providing a mild access to a range of functionalized phenols and aliphatic alcohols. These reactions generally proceed under mild reaction conditions with no need for a photocatalyst or a strong base and show a wide substrate scope as well as excellent functional group tolerance. This work highlights the unique role of NaI that allows a challenging transformation to proceed under mild reaction conditions.
Chemoselective Demethylation of Methoxypyridine
Makino, Kosho,Hasegawa, Yumi,Inoue, Takahide,Araki, Koji,Tabata, Hidetsugu,Oshitari, Tetsuta,Ito, Kiyomi,Natsugari, Hideaki,Takahashi, Hideyo
, p. 951 - 954 (2019/05/10)
A chemoselective demethylation method for various methoxypyridine derivatives has been developed. Treatment of 4-methoxypyridine with L-selectride in THF for 2 h at reflux temperature afforded 4-hydroxypyridine in good yield; no reaction to anisole occurred. The utility of our method was demonstrated by the efficient synthesis of the metabolic substances of the antiulcer agent omeprazole. Chemoselective demethylation at the site of 3,5-dimethyl-4-methoxypyridine in the presence of 4-methoxybenzimidazole was achieved.
Preparation method of pyridine derivative (by machine translation)
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Paragraph 0075-0078; 0121-0122, (2019/12/02)
To the method, piperidine-4-one hydrochloride is used as a raw material, and a series of pyridine derivatives are obtained through halogenation reaction and elimination reaction. The reaction is eliminated by reacting piperidine-4-one hydrochloride with a specific amount of the 3,5 - halogenating agent in a halogenation 3, 3, 5 - reaction with a halogen-3, 3, 5, 5 - based reaction, followed by reaction with a pyridine derivative of a hydroxyl group, an amino group 4 - or a dimethylamino group, respectively, by eliminating the reaction with a different kind of basic agent. The method is simple and convenient to operate, mild in condition, short in technological process, low in waste water yield, environment-friendly, low in cost and beneficial to green industrial production of the pyridine derivative. (by machine translation)
