25294-65-9Relevant academic research and scientific papers
Metallo-Helicoid with Double Rims: Polymerization Followed by Folding by Intramolecular Coordination
Yin, Guang-Qiang,Kandapal, Sneha,Liu, Chung-Hao,Wang, Heng,Huang, Jianxiang,Jiang, Shu-Ting,Ji, Tan,Yan, Yu,Khalife, Sandra,Zhou, Ruhong,Ye, Libin,Xu, Bingqian,Yang, Hai-Bo,Nieh, Mu-Ping,Li, Xiaopeng
, p. 1281 - 1289 (2021)
In this study, we established a feasible strategy to construct a new type of metallo-polymer with helicoidal structure through the combination of covalent polymerization and intramolecular coordination-driven self-assembly. In the design, a tetratopic monomer (M) was prepared with two terminal alkynes in the outer rim for polymerization, and two terpyridines (TPYs) in the inner rim for subsequent folding by selective intramolecular coordination. Then, the linear covalent polymer (P) was synthesized by polymerization of M via Glaser-Hay homocoupling reaction. Finally, intramolecular coordination interactions between TPYs and Zn(II) folded the backbone of P into a right- or left-handed metallo-helicoid (H) with double rims. Owing to multiple positive charges on the inner rim of helicoid, double-stranded DNA molecules (dsDNA) could interact with H through electrostatic interactions. Remarkably, dsDNA allowed exclusive formation of H with right handedness by means of chiral induction.
Self-assembly of emissive metallocycles with tetraphenylethylene, BODIPY and terpyridine in one system
Yan, Yu,Yin, Guang-Qiang,Khalife, Sandra,He, Zhan-Hang,Xu, Chen,Li, Xiaopeng
, p. 597 - 605 (2019)
Tetraphenylethylene (TPE) related (supra)molecules have been intensively investigated due to their aggregation-induced emission (AIE) effect based on the restriction of intramolecular rotation (RIR). Meanwhile, boron-dipyrromethene (BODIPY) tends to emit intense fluorescence with high quantum yields. Herein, we combined TPE, BODIPY and terpyridine (TPY) into one system to study the emissive behaviour of organic building block as well as a self-assembled metallo-supramolecule. The TPY and BODIPY substituents with bulky sizes provide strong hindrance to restrict the rotation of the phenyl groups on TPE, leading to enhancement of emissive properties in both solution and aggregation states. Furthermore, the BODIPY-TPE-TPY ligand (L) was assembled with Zn (II) through coordination-driven self-assembly to form a cyclic dimer (D) with typical AIE characteristics.
Enantioselective hydroesterificative cyclization of 1,6-enynes to chiral γ-lactams bearing a quaternary carbon stereocenter
Dong, Kaiwu,Li, Huimin,Ren, Xinyi,Shen, Chaoren,Tang, Lin,Wang, Peng
supporting information, p. 3561 - 3566 (2021/05/29)
A palladium-catalyzed asymmetric hydroesterification-cyclization of 1,6-enynes with CO and alcohol was developed to efficiently prepare a variety of enantioenriched γ-lactams bearing a chiral quaternary carbon center and a carboxylic ester group. The approach featured good to high chemo-, region-, and enantioselectivities, high atom economy, and mild reaction conditions as well as broad substrate scope. The correlation between the multiple selectivities of such process and the N-substitutes of the amide linker in the 1,6-enyne substrate has been depicted by the crystallographic evidence and control experiments.
Access to Triazolopiperidine Derivatives via Copper(I)-Catalyzed [3+2] Cycloaddition/Alkenyl C?N Coupling Tandem Reactions
Xiao, Guorong,Wu, Kaifu,Zhou, Wei,Cai, Qian
supporting information, p. 4988 - 4991 (2021/10/14)
A copper-catalyzed [3+2] cylcoaddition/ alkenyl C?N coupling tandem reaction was demonstrated. It provided a method for the formation of triazolopiperidine skeletons. (Figure presented.).
Pre-carbonized nitrogen-rich polytriazines for the controlled growth of silver nanoparticles: Catalysts for enhanced CO2chemical conversion at atmospheric pressure
Liu, Jian,Zhang, Xiaoyi,Wen, Bingyan,Li, Yipei,Wu, Jingjing,Wang, Zhipeng,Wu, Ting,Zhao, Rusong,Yang, Shenghong
, p. 3119 - 3127 (2021/05/25)
High catalytic activity and sufficient durability are two unavoidable key indices of an efficient heterogeneous catalyst for the direct carboxylation of terminal alkynes with CO2 conversion. Nitrogen-rich covalent triazine frameworks (CTFs) are promising substrates, while random distribution of some residual -NH2 groups brings challenges to the controlled growth of catalytic species. Here, we adopt a pre-carbonization protocol, annealing below the carbonization temperature, to eliminate the random -NH2 groups in CTFs and meanwhile to promote polycondensation degree under the premise of maintaining the pore structure. Benefiting from the improved condensation and orderly N atoms, p-CTF-250, for which CTFs are annealed at 250 °C, exhibits improved CO2 adsorption capacity and the ability to control the growth of Ag NPs. Mono-dispersed Ag NPs are generated controllably and entrapped to form Ag@p-CTF-250 catalysts. These Ag@p-CTF-250 catalysts were employed in the direct carboxylation of various terminal alkynes with CO2 under mild conditions (50 °C, 1 atm) and showed excellent catalytic activity. In addition, these catalysts have robust recyclability and can be used for at least 5 catalytic runs while retaining yield above 90%. CO2 conversion proceeds well under the synergistic effect between the high CO2 capture capability and the uniform tiny Ag NPs in Ag@p-CTF-250 "nanoreactors". The results represent an efficient strategy for controlling the growth of metallic nanoparticles in porous organic polymer substrates containing disordered heteroatoms.
Organocatalytic Strategy for the Fixation of CO2via Carboxylation of Terminal Alkynes
Shi, Jun-Bin,Bu, Qingqing,Liu, Bin-Yuan,Dai, Bin,Liu, Ning
, p. 1850 - 1860 (2021/01/14)
An organocatalytic strategy for the direct carboxylation of terminal alkynes with CO2 has been developed. The combined use of a bifunctional organocatalyst and Cs2CO3 resulted in a robust catalytic system for the preparation of a range of propiolic acid derivatives in high yields with broad substrate scope using CO2 at atmospheric pressure under mild temperatures (60 °C). This work has demonstrated that this organocatalytic method offers a competitive alternative to metal catalysis for the carboxylation of terminal alkynes and CO2. In addition, this protocol was suitable for the three-component carboxylation of terminal alkynes, alkyl halides, and CO2.
Microwave-assisted fabrication of a mixed-ligand [Cu4(μ3-OH)2]-cluster-based metal–organic framework with coordinatively unsaturated metal sites for carboxylation of terminal alkynes with carbon dioxide
Wang, Wen-Jing,Sun, Zhong-Hua,Chen, Sheng-Chun,Qian, Jun-Feng,He, Ming-Yang,Chen, Qun
, (2021/05/24)
The development of efficient and stable metal–organic framework (MOF) catalysts with coordinatively unsaturated metal sites for modern organic synthesis is greatly important. Herein, a robust [Cu4(μ3-OH)2]-cluster-based MOF (Cu-MOF) with a mixed-ligand system was successfully fabricated by a microwave-assisted method under mild conditions. The as-prepared Cu-MOF catalyst possessing unsaturated Cu (II) sites exhibited excellent catalytic activity toward the direct carboxylation of 1-ethynylbenzene with CO2, and various propiolic acid derivatives were synthesized in moderate to good yields under optimized reaction conditions. Furthermore, the catalyst remained stable and could be easily recycled for five sequential runs without incredible decrease in catalytic efficiency.
A Construction of α-Alkenyl Lactones via Reduction Radical Cascade Reaction of Allyl Alcohols and Acetylenic Acids
Zhang, Hua,Zhang, Guo-Min,He, Shuai,Shi, Zhi-Chuan,Zhang, Xiao-Mei,Wang, Ji-Yu
supporting information, p. 8337 - 8344 (2020/11/03)
An iron-catalyzed cascade reaction of radical reduction of allyl alcohols and acetylenic acids to construct polysubstituted α-alkenyl lactones has been developed. In this paper, various allyl alcohols can form allyl ester intermediates and are further transformed into alkyl radicals, which form products through intramolecular reflex-Michael addition. In addition, this method can be used to prepare spirocycloalkenyl lactones. Interestingly, this protocol can be used to synthesize the skeleton structure of natural products. Moreover, the product can be further transformed into a β-methylene tetrahydrofuran and tetrahydrofuran diene.
Silver Nanoparticles Architectured HMP as a Recyclable Catalyst for Tetramic Acid and Propiolic Acid Synthesis through CO2 Capture at Atmospheric Pressure
Ghosh, Swarbhanu,Ghosh, Aniruddha,Riyajuddin, Sk,Sarkar, Somnath,Chowdhury, Arpita Hazra,Ghosh, Kaushik,Islam, Sk. Manirul
, p. 1055 - 1067 (2020/01/21)
The recent advancement on the tailored synthesis of hypercrosslinked microporous polymer (HMP-2) has assembled significant concentration by the virtue of its adjustable porosity, operative design and absolutely ordering structure. This perfectly structured Ag NPs supported carbocatalyst (Ag-HMP-2) has been synthesized by Friedel-Crafts alkylation between 4,4′-Bis(bromomethyl)-1,1′-biphenyl and carbazole over anhydrous iron(III)chloride catalysis followed by the appending of the silver nanoparticles (Ag NPs) onto the material. The silver nanoparticle was decorated over the HMP-2 to prepare the corresponding catalyst (Ag-HMP-2). The characterization of the newly produced material has been conducted by N2 adsorption/desorption studies, XPS, FE-SEM, transmission electron microscopy (TEM) and Powder X-ray diffraction (PXRD) methods. This microporous catalyst has spectacular activities for the production of tetramic acids from various types of propargylic amine derivatives at 60 °C under atmospheric carbon dioxide pressure. Parallel attempt on fixation of CO2 was executed over terminal alkynes to synthesize propiolic acids under 1 atm pressure. The catalyst (Ag-HMP-2) exhibited sufficient recycling ability for the generation of tetramic acids and propiolic acids up to five catalytic runs without reduction in its catalytic activity.
Gold(i)-catalyzed pathway-switchable tandem cycloisomerizations to indolizino[8,7-: B] indole and indolo[2,3-a] quinolizine derivatives
Liu, Chengjun,Sun, Zenghui,Xie, Fukai,Liang, Guoduan,Yang, Lu,Li, Yaqiao,Cheng, Maosheng,Lin, Bin,Liu, Yongxiang
supporting information, p. 14418 - 14421 (2019/12/05)
Experimental and theoretical explorations were performed on the pathways of the cascade cycloisomerizations of tryptamine-N-ethynylpropiolamide substrates. The methodology provided a common strategy to access either indolizino[8,7-b]indoles or indolo[2,3-
