1849-25-8Relevant academic research and scientific papers
Self-assembly of decoupled borazines on metal surfaces: The role of the peripheral groups
Kalashnyk, Nataliya,Ganeshnagaswaran, Praveen,Kervyn, Simon,Riello, Massimo,Moreton, Ben,Jones, Tim S.,Devita, Alessandro,Bonifazi, Davide,Costantini, Giovanni
, p. 11856 - 11862 (2014)
Two borazine derivatives have been synthesised to investigate their self-assembly behaviour on Au(111) and Cu(111) surfaces by scanning tunnelling microscopy (STM) and theoretical simulations. Both borazines form extended 2D networks upon adsorption on bo
Cyclic (Alkyl)(amino)carbene Ligand-Promoted Nitro Deoxygenative Hydroboration with Chromium Catalysis: Scope, Mechanism, and Applications
Zhao, Lixing,Hu, Chenyang,Cong, Xuefeng,Deng, Gongda,Liu, Liu Leo,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 1618 - 1629 (2021/01/25)
Transition metal catalysis that utilizes N-heterocyclic carbenes as noninnocent ligands in promoting transformations has not been well studied. We report here a cyclic (alkyl)(amino)carbene (CAAC) ligand-promoted nitro deoxygenative hydroboration with cost-effective chromium catalysis. Using 1 mol % of CAAC-Cr precatalyst, the addition of HBpin to nitro scaffolds leads to deoxygenation, allowing for the retention of various reducible functionalities and the compatibility of sensitive groups toward hydroboration, thereby providing a mild, chemoselective, and facile strategy to form anilines, as well as heteroaryl and aliphatic amine derivatives, with broad scope and particularly high turnover numbers (up to 1.8 × 106). Mechanistic studies, based on theoretical calculations, indicate that the CAAC ligand plays an important role in promoting polarity reversal of hydride of HBpin; it serves as an H-shuttle to facilitate deoxygenative hydroboration. The preparation of several commercially available pharmaceuticals by means of this strategy highlights its potential application in medicinal chemistry.
Effect of the Linking Group on the Thermoelectric Properties of Poly(Schiff Base)s and Their Metallopolymers
Li, Jiahua,Wang, Zitong,Sun, Zelin,Xu, Linli,Wong, Wai-Yeung
supporting information, p. 1911 - 1917 (2021/06/21)
As polymer-based thermoelectric (TE) materials possess attractive features such as light weight, flexibility, low toxicity and ease of processibility, an increasing number of conducting polymers and their composites with high TE performances have been developed in recent years. Up to date, however, the research focusing on the structure-performance relationship remains rare. In this paper, two series of poly(Schiff base)s with either C=C or C≡C linker and their metallopolymers were synthesized and doped with single-walled carbon nanotubes to evaluate how the linking groups affected the TE properties of the resulting composites. Apart from the effect exerted by the morphology, experimental results suggested that the linkers played a key role in determining the band gaps, preferred molecular conformation and extent of conjugation of the polymers, which became key factors that influenced the TE properties of the resulting materials. Additionally, upon coordination with transition metal ions, the TE properties could be tuned readily.
Copper(0) nanoparticle catalyzed Z-Selective Transfer Semihydrogenation of Internal Alkynes
Moran, Maria Jesus,Martina, Katia,Bieliunas, Vidmantas,Baricco, Francesca,Tagliapietra, Silvia,Berlier, Gloria,De Borggraeve, Wim M.,Cravotto, Giancarlo
supporting information, p. 2850 - 2860 (2021/05/06)
The use of copper(0) nanoparticles in the transfer semihydrogenation of alkynes has been investigated as a lead-free alternative to Lindlar catalysts. A stereo-selective methodology for the hydrogenation of internal alkynes to the corresponding (Z)-alkenes in high isolated yields (86% average) has been developed. This green and sustainable transfer hydrogenation protocol relies on non-noble copper nanoparticles for reduction of both electron-rich and electron-deficient, aliphatic-substituted and aromatic- substituted internal alkynes. Polyols, such as ethylene glycol and glycerol, have been proven to act as hydrogen sources, and excellent stereo- and chemoselectivity have been observed. Enabling technologies, such as microwave and ultrasound irradiation are shown to enhance heat and mass transfer, whether used alone or in combination, resulting in a decrease in reaction time from hours to minutes. (Figure presented.).
Co3O4 nanoparticles embedded in triple-shelled graphitic carbon nitride (Co3O4/TSCN): a new sustainable and high-performance hierarchical catalyst for the Pd/Cu-free Sonogashira–Hagihara cross-coupling reaction
Ghodsinia, Sara S. E.,Akhlaghinia, Batool,Jahanshahi, Roya
, p. 3217 - 3244 (2021/05/17)
Inspired by the synthesis of triple-shelled periodic mesoporous organosilica hollow spheres, a straightforward and controllable approach for the preparation of Co3O4 NPs embedded in triple-shelled graphitic carbon nitride has been es
Synthesis of N-Heterocyclic Carbine Silver(I) and Palladium(II) Complexes with Acylated Piperazine Linker and Catalytic Activity in Three Types of C—C Coupling Reactions
Liu, Qingxiang,Zhang, Xiantao,Zhao, Zhixiang,Li, Xinying,Zhang, Wei
supporting information, p. 605 - 613 (2021/02/01)
Two bis-imidazolium salts LH2·Cl2 and LH2·(PF6)2 with acylated piperazine linker and two N-heterocyclic carbene (NHC) silver(I) and palladium(II) complexes [L2Ag2](PF6)2 (1) and [L2Pd2Cl4] (2) were prepared. The crystal structures of LH2·Cl2 and 1 were confirmed by X-ray analysis. In 1, one 26-membered macrometallocycle was generated through two silver(I) ions and two bidentate ligands L. The catalytic activity of 2 was investigated in Sonogashira, Heck-Mizoroki and Suzuki-Miyaura reactions. The results displayed that these C—C coupling reactions can be smoothly carried out under the catalysis of 2.
Decorated palladium nanoparticles on mesoporous organosilicate as an efficient catalyst for Sonogashira coupling reaction
Mohajer, Fatemeh,Mohammadi Ziarani, Ghodsi,Badiei, Alireza
, p. 589 - 601 (2020/09/17)
Abstract: Reforming mesoporous silica was provided by the reaction of SBA‐15 with (3-aminopropyl)triethoxysilane, the product of which was treated with furfural to give SBA-propyl-imine-furan. In the next step, palladium chloride was attached to the funct
Method for preparing amine through catalytic reduction of nitro compound by cyclic (alkyl) (amino) carbene chromium complex
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Paragraph 0015, (2021/04/17)
The cyclic (alkyl) (amino) carbene chromium complex is prepared from corresponding ligand salt, alkali and CrCl3 and used for catalyzing pinacol borane to reduce nitro compounds in an ether solvent under mild conditions to generate corresponding amine. The method for preparing amine has the advantages of cheap and accessible raw materials, mild reaction conditions, wide substrate application range, high selectivity and the like, and is simple to operate.
Metal-Free and syn-Selective Hydrohalogenation of Alkynes through a Pseudo-Intramolecular Process
Asahara, Haruyasu,Mukaijo, Yusuke,Muragishi, Kengo,Iwai, Kento,Ito, Akitaka,Nishiwaki, Nagatoshi
, p. 5747 - 5755 (2021/10/20)
A new metal-free hydrohalogenation method for alkynes has been developed, which proceeds through a pseudo-intramolecular process. In this reaction, ethynylaniline serves as a substrate to quantitatively form an anilinium salt upon treatment with hydrochloric acid. The spatial proximity facilitates the efficient electrophilic addition of HCl to the ethynyl group in syn-mode, affording the corresponding chloroalkene without overaddition. This protocol was applied to HBr and HI, and the corresponding bromo- and iodoalkenes were obtained, respectively. The obtained chloroalkene was converted to tri-substituted alkenes possessing different aryl/alkynyl groups through Pd-catalyzed cross-coupling reactions.
A 1D palladium coordination polymer and its catalytic activity in microwave-assisted Sonogashira reactions
Lee, Gang Min,Lee, Soon W.
supporting information, (2021/04/27)
A palladium coordination polymer, [Pd(dppp)(L)](OTf)2·(H2O)] (1) (dppp = 1,3-bis(diphenylphosphino)propane), was prepared from a bipyridine-type ligand (L = (4-py)–CH = N–C10H6–N = CH–(4-py)) and [Pd(dppp)](OTf)
