2617-79-0Relevant articles and documents
Imidazolium-Salt-Functionalized Covalent Organic Frameworks for Highly Efficient Catalysis of CO2 Conversion
Qiu, Jikuan,Zhao, Yuling,Li, Zhiyong,Wang, Huiyong,Shi, Yunlei,Wang, Jianji
, p. 2421 - 2427 (2019)
The conversion of CO2 into valuable chemicals is an ideal pathway for CO2 utilization in industry, although the development of highly efficient catalysts remains a challenge. Herein, the design and synthesis of two covalent organic frameworks (COFs) functionalized with imidazolium salts were reported as catalysts for CO2 conversion. The resultant COFs possessed highly crystalline structures, showed high stability and surface area, and contained dense catalytic active sites on the pore walls. They exhibited outstanding catalytic performances for the reaction of CO2 with epoxides without any solvent or cocatalyst under mild conditions and afforded a record turnover number of 495 000. In addition, the COFs could serve as effective catalysts in the reductive reaction of CO2 with amines. The results presented here thus demonstrate the exceptional potential of the functionalized COFs for various challenging CO2 transformations.
Design, synthesis and anticancer evaluation of 3-methyl-1H-indazole derivatives as novel selective bromodomain-containing protein 4 inhibitors
Dong, Ru,Zhang, Cheng,Wang, Chao,Zhou, Xin,Li, Wen,Zhang, Jin-Yang,Wang, Min,Xu, Yong,Sun, Li-Ping
, (2022/01/11)
Bromodomain-containing Protein 4 (BRD4), an ‘epigenetic reader’, regulates chromatin structure and gene expression via recognizing and binding acetylated lysine in histones. BRD4 has become a therapeutic target for cancers because it promotes the expression of the tumor genes, such as c-Myc, NF-κB, and Bcl-2. In this study, a new series of 3-methyl-1H-indazole derivatives were designed via virtual screening and structure-based optimization. All compounds were synthesized and evaluated for their inhibitory activities to BRD4-BD1 and their antiproliferative effects in cancer cell lines. Among them, several compounds (such as 9d, 9u and 9w) exhibited strong BRD4-BD1 affinities and inhibition activities, and potently suppressed MV4;11 cancer cell line proliferation. Among them, compound 9d showed excellent selectivity for BRD4 and effectively suppressed c-Myc, the downstream protein of BRD4. This study provided new lead compounds for further biological evaluation on BRD4.
Novel 4-phenoxypyridine derivatives bearing imidazole-4-carboxamide and 1,2,4-triazole-3-carboxamide moieties: Design, synthesis and biological evaluation as potent antitumor agents
Liu, Ju,Liu, Fang,Li, Zhen,Li, Chunyan,Wu, Shuang,Shen, Jiwei,Wang, Huan,Du, Siyuan,Wei, Hao,Hou, Yunlei,Ding, Shi,Chen, Ye
, (2022/01/26)
Two series of novel 4-phenoxypyridine derivatives containing imidazole-4-carboxamide and 4-methyl-5-oxo-4,5-dihydro-1,2,4-triazole-3-carboxamide moieties were synthesized and evaluated for their in vitro inhibitory activities against c-Met kinase and anti
Access to α,α-dihaloacetophenones through anodic C[dbnd]C bond cleavage in enaminones
Zhang, Zhenlei,Yang, Jiusi,Wu, Kairui,Yu, Renjie,Bu, Jiping,Huang, Zijun,Li, Shaoke,Ma, Xiantao
supporting information, (2021/12/20)
We have developed a method to synthesize α,α-dihaloketones under electrochemical conditions. In this reaction, the Cl- or Br- is oxidized to Cl2 or Br2 at the anode, which undergoes two-step addition reactions with the N,N-dimethyl enaminone, and finally breaks C[dbnd]C of the N,N-dimethyl enaminone to generate α,α-dihaloketones. The electrosynthesis reaction can be conveniently carried out in an undivided electrolytic cell at room temperature. In addition, various functional groups are compatible with this green protocol which can be applied simultaneously to the gram scale without significantly lower yield.
Enantioselective Synthesis of Azetidines through [3 + 1]-Cycloaddition of Donor-Acceptor Aziridines with Isocyanides
Zhang, Fengcai,Sang, Xinpeng,Zhou, Yuqiao,Cao, Weidi,Feng, Xiaoming
supporting information, p. 1513 - 1517 (2022/03/01)
The enantioselective [3 + 1]-cycloaddition of racemic donor-acceptor (D-A) aziridines with isocyanides was first realized under mild reaction conditions using a chiral N,N′-dioxide/MgIIcomplex as catalyst, providing a facile route to enantioenriched exo-imido azetidines with good to excellent yield (up to 99%) and enantioselectivity (up to 94% ee). An obvious chiral amplification effect was observed in this system, and an explanation was elucidated based on the experimental investigation and X-ray crystal structure of the enantiomerically pure catalyst.
Reductive Formylation of Nitroarenes using HCOOH over Bimetallic C?N Framework Derived from the Integration of MOF and COF
Kumar Kar, Ashish,Srivastava, Rajendra
, p. 3174 - 3183 (2021/05/27)
CoZn embedded C?N framework is prepared by the carbonization of CoZn containing MOF integrated with COF porous architecture in Ar atmosphere. The graphitic nature of porous carbon is confirmed from Raman analysis. The porosity and nanostructure information are retrieved from N2-sorption and transmission electron microscopic analysis, respectively. The incorporation of different metals and their oxidation states and types of nitrogen present in the C?N framework are confirmed from X-ray photoelectron spectroscopy. The basicity of the materials is determined from a CO2-temperature programmed desorption. ZnCo embedded C?N framework exhibits excellent activity in the selective reductive formylation using HCOOH. For comparison, more than 15 materials are prepared, and their activities are compared. Several control experiments are performed to establish a structure-activity relation. The recycling experiment, hot-filtration test, and poisoning experiment demonstrate the metal embedded porous C?N framework‘s recyclability and stability. A reaction mechanism for the reductive N-formylation of nitroaromatics is presented based on structure-activity relationship, control reactions, and physicochemical characterizations. The development of interesting MOF-COF-derived metal nanoclusters embedded C?N framework for selective reductive formylation of nitroaromatics using formic acid will be highly attractive to catalysis researchers and industrialists.
Copper-Catalyzed Cascade N-Dealkylation/N-Methyl Oxidation of Aromatic Amines by Using TEMPO and Oxygen as Oxidants
Li, Dianjun,Wang, Shihaozhi,Yang, Jiale,Yang, Jinhui
supporting information, p. 6768 - 6772 (2021/12/31)
A novel tandem N-dealkylation and N-methyl aerobic oxidation of tertiary aromatic amines to N-arylformamides using copper and TEMPO has been developed. This methodology suggested an alternative synthetic route from N-methylarylamines to N-arylformamides.
Supported CuII Single-Ion Catalyst for Total Carbon Utilization of C2 and C3 Biomass-Based Platform Molecules in the N-Formylation of Amines
Brückner, Angelika,Dai, Xingchao,Kreyenschulte, Carsten,Rabeah, Jabor,Shi, Feng,Wang, Xinzhi
, p. 16889 - 16895 (2021/09/25)
The shift from fossil carbon sources to renewable ones is vital for developing sustainable chemical processes to produce valuable chemicals. In this work, value-added formamides were synthesized in good yields by the reaction of amines with C2 and C3 biomass-based platform molecules such as glycolic acid, 1,3-dihydroxyacetone and glyceraldehyde. These feedstocks were selectively converted by catalysts based on Cu-containing zeolite 5A through the in situ formation of carbonyl-containing intermediates. To the best of our knowledge, this is the first example in which all the carbon atoms in biomass-based feedstocks could be amidated to produce formamide. Combined catalyst characterization results revealed preferably single CuII sites on the surface of Cu/5A, some of which form small clusters, but without direct linking via oxygen bridges. By combining the results of electron paramagnetic resonance (EPR) spin-trapping, operando attenuated total reflection (ATR) IR spectroscopy and control experiments, it was found that the formation of formamides might involve a HCOOH-like intermediate and .NHPh radicals, in which the selective formation of .OOH radicals might play a key role.
Acid-catalyzed chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines
Guo, Luxia,Chen, Zihao,Zhu, Hongmei,Li, Minghao,Gu, Yanlong
supporting information, p. 1419 - 1422 (2020/11/12)
Chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines were described, which were established on the basis of either a C[sbnd]C bond cleavage or a rearrangement process of a reaction intermediate. These reactions proceeded in a condition-determined manner with good functional group tolerance. In the first model, 2,2-dimethoxyacetaldehyde reacted with aniline to form a new C[sbnd]N bond, in the presence of O2, via a C[sbnd]C bond cleavage reaction. However, in the second model, by performing the reaction in the absence of O2, Heyns rearrangement occurred and generated a new C[sbnd]O bond to form methyl phenylglycinate. Such condition-determined reactions not only offered the new way for value-added conversion of biomass-derived platform molecule, 2, 2-dimethoxyacetaldehyde, but also provided efficient methods for the synthesis of N-arylformamides and methyl phenylglycinates.
HCl-mediated transamidation of unactivated formamides using aromatic amines in aqueous media
Dhawan, Sanjeev,Girase, Pankaj Sanjay,Kumar, Vishal,Karpoormath, Rajshekhar
, p. 3729 - 3739 (2021/10/14)
We report transamidation protocol to synthesize a range of secondary and tertiary amides from weakly nucleophilic aromatic and hetero-aryl amines with low reactive formamide derivatives, utilizing hydrochloric acid as catalyst. This current acid mediated strategy is beneficial because it eliminates the need for a metal catalyst, promoter or additives in the reaction, simplifies isolation and purification. Notably, this approach conventionally used to synthesize molecules on gram scales with excellent yields and a high tolerance for functional groups.
