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One‐Pot Three‐Component Synthesis of Vicinal Diamines via In Situ Aminal Formation and Carboamination 下载免费PDF全文
Ugo Orcel Prof. Dr. Jerome Waser 《Angewandte Chemie (International ed. in English)》2016,55(41):12881-12885
A synthesis of vicinal diamines via in situ aminal formation and carboamination of allyl amines is reported. Employing highly electron‐poor trifluoromethyl aldimines in their stable hemiaminal form was key to enable both a fast and complete aminal formation as well as the palladium‐catalyzed carboamination step. The conditions developed allow the introduction of a wide variety of alkynyl, vinyl, aryl, and hetereoaryl groups with complete regioselectivity and high diastereoselectivity. The reaction exhibits a high functional‐group tolerance. Importantly, either nitrogen atom of the imidazolidine products can be selectively deprotected, while removal of the aminal tether can be achieved in a single step under mild conditions to reveal the free diamine. We expect that this work will promote the further use of mixed aminal tethers in organic synthesis. 相似文献
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Unprecedented Transformation of a Directing Group Generated In Situ and Its Application in the One‐Pot Synthesis of 2‐Alkenyl Benzonitriles 下载免费PDF全文
Ravi Kumar Rajesh K. Arigela Dr. Bijoy Kundu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(33):11807-11812
An unprecedented protocol for the transformation of benzoyl azides into benzonitrile derivatives via iminophosphoranes generated in situ is described. The strategy was successfully applied to the de‐novo synthesis of 2‐alkenylated benzonitrile derivatives from benzoyl azides through ortho C?H activation/alkenylation followed by subsequent rearrangement. The salient features of this protocol involve incorporation of two important functionalities through cyanation and olefination in one pot under mild reaction conditions by using a less expensive Ru catalyst. The mechanism was established by isolating and characterising (using 31P NMR) an intermediate with two ortho functionalities, iminophosphorane and olefin, under specific reaction conditions. 相似文献
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The First One‐Pot Synthesis of Metal–Organic Frameworks Functionalised with Two Transition‐Metal Complexes 下载免费PDF全文
Dr. Ana E. Platero‐Prats Dr. Antonio Bermejo Gómez Dr. Louise Samain Prof. Xiaodong Zou Prof. Belén Martín‐Matute 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(2):861-866
The synthesis of a metal–organic framework (UiO‐67) functionalised simultaneously with two different transition metal complexes (Ir and Pd or Rh) through a one‐pot procedure is reported for the first time. This has been achieved by an iterative modification of the synthesis parameters combined with characterisation of the resulting materials using different techniques, including X‐ray absorption spectroscopy (XAS). The method also allows the first synthesis of UiO‐67 with a very wide range of loadings (from 4 to 43 mol %) of an iridium complex ([IrCp*(bpydc)(Cl)Cl]2?; bpydc=2,2′‐bipyridine‐5,5′‐dicarboxylate, Cp*=pentamethylcyclopentadienyl) through a pre‐functionalisation methodology. 相似文献
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Facile One‐Pot,One‐Step Synthesis of a Carbon Nanoarchitecture for an Advanced Multifunctonal Electrocatalyst 下载免费PDF全文
Dr. Yang Hou Prof. Junhong Chen 《Angewandte Chemie (International ed. in English)》2014,53(25):6496-6500
A one‐pot/one‐step synthesis strategy was developed for the preparation of a nitrogen‐doped carbon nanoarchitecture with graphene‐nanosheet growth on the inner surface of carbon nanotubes (CNTs). The N‐graphene/CNT hybrids exhibit outstanding electrocatalytic activity for several important electrochemical reactions as a result of their unique morphology and defect structures, such as high but uniform nitrogen doping, graphene insertion into CNTs, considerable surface area, and the presence of iron nanoparticles. The high‐yield synthetic process features high efficiency, low‐cost, straightforward operation, and simple equipment. 相似文献
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Zhenhai Wen Suqin Ci Yang Hou Junhong Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(25):6614-6618
A one‐pot/one‐step synthesis strategy was developed for the preparation of a nitrogen‐doped carbon nanoarchitecture with graphene‐nanosheet growth on the inner surface of carbon nanotubes (CNTs). The N‐graphene/CNT hybrids exhibit outstanding electrocatalytic activity for several important electrochemical reactions as a result of their unique morphology and defect structures, such as high but uniform nitrogen doping, graphene insertion into CNTs, considerable surface area, and the presence of iron nanoparticles. The high‐yield synthetic process features high efficiency, low‐cost, straightforward operation, and simple equipment. 相似文献
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Chenxu Zhao Fang Zuo Zhijian Liao Zhenli Qin Sinan Du Zhigang Zhao 《Macromolecular rapid communications》2015,36(10):909-915
Inspired by the molecular mechanics of mussel adhesive formation, a novel water‐soluble fluorescent macromolecule (polydopamine–polyethyleneimine (PDA–PEI)) is prepared by one‐pot copolymerization of dopamine (DA) and PEI. In this method, DA is polymerized to form PDA, which is then coupled with PEI mainly through Michael addition. The fluorescence property of PDA–PEI is mainly attributed to the Michael addition of PEI on the 5,6‐dihydroxyindole (DHI) units of PDA, where PEI can form hydrogen bonds with oxidative products such as DHI and force the DHI units to twist out of plane, resulting in a decrease in the intra‐ and intermolecular coupling of PDA. In addition, the influence of various metal cations on the fluorescence of the PDA–PEI copolymer is investigated. This work may facilitate the development of new strategies for controlling the emission characteristics of PDA.
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Dr. Xinman Tu Prof. Dr. Shenglian Luo Guixiang Chen Prof. Jinghong Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(45):14359-14366
Herein, a chemically bonded BiOBr–graphene composite (BiOBr–RG) was prepared through a facile in situ solvothermal method in the presence of graphene oxide. Graphene oxide could be easily reduced to graphene under solvothermal conditions, and simultaneously BiOBr nanoplates with pure tetragonal phase were grown uniformly on the graphene surface. The structure and photoelectrochemical properties of the resulting materials were characterized by transmission electron microscopy (TEM), X‐ray diffraction (XRD), Fourier‐transform infrared (FTIR) spectroscopy, Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS), and impedance and photocurrent action measurements. The combination of BiOBr and graphene introduces some properties of graphene into the photocatalysis reaction, such as excellent conductivity, adsorptivity, and controllability. A remarkable threefold enhancement in the degradation of rhodamine B (RhB) was observed with as‐prepared BiOBr–RG as compared with pure BiOBr under visible light (λ>420 nm). The enhanced photocatalytic activity could be attributed to the great adsorptivity of dyes, the extended photoresponse range, the negative shift in the Fermi level of BiOBr–RG, and the high migration efficiency of photoinduced electrons, which may effectively suppress the charge recombination. 相似文献
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One‐Pot Green Synthesis of Thiazolo[3,2‐a]pyridine Derivatives via Tandem Cyclization in Aqueous Media 下载免费PDF全文
Muthusamy Boominathan Muthupandi Nagaraj Chellaiah Maheshwaran Shanmugam Muthusubramanian Nattamai Bhuvanesh 《Journal of heterocyclic chemistry》2014,51(1):244-248
Facile, three‐component domino reactions of readily available thioglycolic acid/ethyl thioglycolate, aromatic aldehydes, and malononitrile/ethyl cyanoacetate in aqueous potassium carbonate at room temperature afforded thiazolo[3,2‐a]pyridine derivatives chemoselectively in good to excellent yield. All the formed 4H‐chromenes were characterized by spectral and X‐ray methods. 相似文献
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A facile, convenient, and one‐pot multi‐step synthesis of substituted piperidin‐2‐ones from the Baylis–Hillman alcohols derived from various aldehydes and acrylonitrile, involving Johnson–Claisen rearrangement, reduction of an α,β‐unsaturated nitrile moiety into the saturated amine‐skeleton, followed by cyclization, in an operationally simple procedure, is described. 相似文献
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Franziska Debatin Arne Thomas Prof. Dr. Alexandra Kelling Niklas Hedin Dr. Zoltan Bacsik Dr. Irena Senkovska Dr. Stefan Kaskel Prof. Dr. Matthias Junginger Holger Müller Uwe Schilde Prof. Dr. Christian Jäger Prof. Dr. Alwin Friedrich Dr. Hans‐Jürgen Holdt Prof. Dr. 《Angewandte Chemie (International ed. in English)》2010,49(7):1258-1262
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Kazuaki Kudo Takuya Yoshizawa Takashi Hamada Jun Li Seiji Sakamoto Shinsaku Shiraishi 《Macromolecular rapid communications》2006,27(17):1430-1436
Summary: Four constitutionally isomeric copoly(amide acid)s (coPAAs), two alternating and two random, have been successfully obtained from the same combination of one non‐symmetrical alicyclic tetracarboxylic dianhydride (1.0 molar equivalents) and two symmetric aromatic diamines (0.5 molar equivalents each) by only slightly changing the reaction procedures. When the reaction mixture is subjected to chemical imidization conditions without isolation of coPAAs, the corresponding copolyimides (coPIs) are obtained in one pot. All of the coPIs are slightly yellow amorphous powders and the solubility of them is similar to each other. The glass transition temperatures of the alternating coPIs are lower in comparison to those of the random coPIs.
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A highly versatile approach to fabricate functional gold nanoparticle (AuNP)‐polymer hybrids is demonstrated by employing sulfonated block copolymers. The 3–5 nm sized ionic domain of the sulfonated poly(styrene‐block‐methylbutylene) (SnMBm) copolymers can be utilized as a nanoreactor where the Au ions can be selectively sequestered and reduced to AuNPs using a simple photochemical method. The size of the AuNPs can be adjusted in fine‐steps from 2.0 ± 0.3 to 3.9 ± 0.5 nm by changing the sulfonation levels of the SnMBm copolymers. Remarkably, significantly improved methanol oxidation properties are achieved with the hybrid materials owing to the ion conducting–SO3H groups and the interconnected network of AuNPs confined within the self‐assembled microstructures, which provides electronic conductivity. 相似文献
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Xu Zhang Jiao Sun Guangfeng Wei Zhipan Liu Huimin Yang Kaimin Wang Honghan Fei 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(9):2870-2875
The reported metal–organic framework (MOF) catalyst realizes CO2 to methanol transformation under ambient conditions. The MOF is one rare example containing metal‐free N‐heterocyclic carbene (NHC) moieties, which are installed using an in situ generation strategy involving the incorporation of an imidazolium bromide based linker into the MOF by postsynthetic ligand exchange. Importantly, the resultant NHC‐functionalized MOF is the first catalyst capable of performing quantitative hydrogen transfer from silanes to CO2, thus achieving quantitative (>99 %) methanol yield. Density‐functional theory calculations indicate the high catalytic activity of the NHC sites in MOFs are attributed to the decreased reaction barrier of a reaction route involving the formation of an NHC‐silane adduct. In addition, the MOF‐immobilized NHC catalyst shows enhanced stability for up to eight cycles without base activation, as well as high selectivity towards the desired silyl methoxide product. 相似文献