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1.
Taoufik Rohand Victor N. Mkpenie Mohammadine El Haddad Istvn E. Mark 《Journal of heterocyclic chemistry》2019,56(2):690-695
A novel one‐pot synthesis of 3‐amino‐1,2,4‐triazole developed via iron (III) catalyzed route is reported. The new method is more efficient, simple, and convenient and presents a concise new strategy for the synthesis of 3‐amino‐1,2,4‐triazole derivatives. The iron (III) complex intermediate assisted in the intramolecular bond cyclization owing to its Lewis acidity or oxidizing properties. A series of aromatic nitriles bearing different electron‐donating and electron‐withdrawing groups substituted at para and/or ortho positions were also investigated. The position of the substituents affected the yield of the final compound, with the para‐substituted substrates giving relatively higher yields. 相似文献
2.
Transition‐Metal‐Free Synthesis of N‐Hydroxy Oxindoles by an Aza‐Nazarov‐Type Reaction Involving Azaoxyallyl Cations
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Wenzhi Ji Dr. Yahu A. Liu Prof. Dr. Xuebin Liao 《Angewandte Chemie (International ed. in English)》2016,55(42):13286-13289
A novel transition‐metal‐free method to construct N‐hydroxy oxindoles by an aza‐Nazarov‐type reaction involving azaoxyallyl cation intermediates is described. A variety of functional groups were tolerated under the weak basic reaction conditions and at room temperature. A one‐pot process was also developed to make the reaction even more practical. This method provides alternative access to oxindoles and their biologically active derivatives. 相似文献
3.
Jui‐Hsiang Liu Po‐Chih Yang Yi‐Hong Chiu 《Journal of polymer science. Part A, Polymer chemistry》2006,44(20):5933-5942
A novel method was developed with surfmer‐cluster‐stabilized silver nanoparticles to prepare high‐performance, gradient‐refractive‐index (GRIN) plastic rods based on methyl methacrylate. To fabricate the GRIN plastic rods, a novel polymerizable surfactant (surfmer) of 4‐(11‐acryloxyundecyloxy)benzoic acid (AUBA) was synthesized. Silver nanoparticles were prepared with a reverse micelle method in the presence of the novel surfmer. During the fabrication of the silver nanoparticles, the sodium salt of AUBA was formed. GRIN plastic rods were fabricated through centrifugal polymerization and then were heat‐treated at 100 °C under 0.1 Torr for 24 h to remove residual monomers and water. The distribution of the surfmer‐cluster‐stabilized nanoparticles inside the plastic rods was studied with transmission electron microscopy (TEM). The real‐image transmission through the fabricated rods was also confirmed. The results obtained in this investigation suggested that the control of the distribution of surfmer‐cluster‐stabilized nanoparticles could be used to fabricate GRIN rods. Furthermore, the existence of the crosslink‐like surfmers increased the thermal stability of the plastic rods. The GRIN distribution of the rods was established by the dispersion of nanoparticles inside the plastic rods through TEM analysis, refractive‐index analysis, and real‐image transmission. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5933–5942, 2006 相似文献
4.
Metal‐Free Synthetic Approach to 3‐Monosubstituted Unsymmetrical 1,2,4,5‐Tetrazines Useful for Bioorthogonal Reactions
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Yangyang Qu François‐Xavier Sauvage Dr. Gilles Clavier Prof. Fabien Miomandre Prof. Pierre Audebert 《Angewandte Chemie (International ed. in English)》2018,57(37):12057-12061
A facile, efficient and metal‐free synthetic approach to 3‐monosubstituted unsymmetrical 1,2,4,5‐tetrazines is presented. Dichloromethane (DCM) is for the first time recognized as a novel reagent in the synthetic chemistry of tetrazines. Using this novel approach 11 3‐aryl/alkyl 1,2,4,5‐tetrazines were prepared in excellent yields (up to 75 %). The mechanism of this new reaction, including the role of DCM in the tetrazine ring formation, has been investigated by 13C labeling of DCM, and is also presented and discussed as well as the photophysical and electrochemical properties. 相似文献
5.
《Journal of heterocyclic chemistry》2018,55(3):670-684
A number of β‐enaminones with secondary amino group (alkyl, cyclopropyl, and aryl) were prepared from corresponding β‐diketones. Two general protocols for their palladium‐catalyzed intramolecular C–N cross‐coupling were established to give corresponding N‐substituted condensed tetrahydropyridines in good yields. The methodology is applicable for a wide variety of structural motifs. The work also extends the applicability of novel, recently established, palladium precatalysts to new substrates. 相似文献
6.
Phosphine‐Catalyzed Annulations of 4,4‐Dicyano‐2‐Methylenebut‐3‐enoates with Maleimides and Maleic Anhydride
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Xiao‐Nan Zhang Gen‐Qiang Chen Dr. Xiang‐Ying Tang Dr. Yin Wei Dr. Min Shi 《Angewandte Chemie (International ed. in English)》2014,53(40):10768-10773
A novel phosphine‐catalyzed [4+1] annulation of maleimides with 4,4‐dicyano‐2‐methylenebut‐3‐enoates has been developed to afford spirocyclic products, and the maleimides serves as C1 synthons. Moreover, a phosphine‐catalyzed formal [3+2] annulation between 4,4‐dicyano‐2‐methylenebut‐3‐enoates and maleic anhydride has been also achieved, and maleic anhydride behaved as a C3 synthon in the reaction, thus efficiently affording the functionalized cyclopentenones. A stable phosphinium‐containing zwitterionic compound is the key reactive intermediate in both annulations and was successfully isolated. Plausible mechanisms have been proposed on the basis of control experiments and deuterium‐labeling experiments. 相似文献
7.
Solution‐Based Fabrication of Narrow‐Disperse ABC Three‐Segment and Θ‐Shaped Nanoparticles
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Zhen Zhang Changming Zhou Haiyan Dong Daoyong Chen 《Angewandte Chemie (International ed. in English)》2016,55(21):6182-6186
Nanoparticles sized tens of nm with not only a highly complex but also a highly regular nanostructure, although ubiquitous in nature, are very difficult to prepare artificially. Herein, we report efficient solution‐based preparation of narrow‐disperse ABC three‐segment hierarchical nanoparticles (HNPs) with a size of tens of nm through a three‐level hierarchical self‐assembly of A‐b‐B‐b‐C triblock copolymers in solution. An ABC HNP is composed of three nanoparticles, A, B, and C that are linearly connected; in the ABC HNP, the B nanoparticle is sandwiched between the A and C nanoparticles. The method for the preparation is highly efficient, because all of the A‐b‐B‐b‐C chains in the solution are converted into the ABC HNPs. Furthermore, the ABC HNPs self‐assembled into Θ‐shaped HNPs tens nm in size. Both the ABC and Θ‐shaped HNPs, are highly complex but highly regular, and are novel HNPs, and they should be very promising for addressing various theoretical and practical problems. 相似文献
8.
A novel synthetic method for the preparation of 5‐aryl‐7‐(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐2‐phenylpyrazolo[1,5‐c]‐pyrimidines and 1‐(5‐aryl‐2‐phenylpyrazolo[1,5‐c]pyrimidin‐7‐yl)‐3‐methyl‐1H‐pyrazol‐5‐ols is provided by condensative cyclization of 5‐aryl‐7‐hydrazino‐2‐phenylpyrazolo[1,5‐c]pyrimidines with 1,3‐dicarbonyl compounds. The study of the more reactive position for electrophilic substitusion reactions on such ring system was also achieved. 相似文献
9.
Dr. Xu Deng Shao‐Fei Ni Zheng‐Yu Han Yu‐Qing Guan Prof. Dr. Hui Lv Prof. Dr. Li Dang Prof. Dr. Xu‐Mu Zhang 《Angewandte Chemie (International ed. in English)》2016,55(21):6295-6299
An enantioselective rhodium(I)‐catalyzed cycloisomerization reaction of challenging (E)‐1,6‐enynes is reported. This novel process enables (E)‐1,6‐enynes with a wide range of functionalities, including nitrogen‐, oxygen‐, and carbon‐tethered (E)‐1,6‐enynes, to undergo cycloisomerization with excellent enantioselectivity, in a high‐yielding and operationally simple manner. Moreover, this RhI‐diphosphane catalytic system also exhibited superior reactivity and enantioselectivity for (Z)‐1,6‐enynes. A rationale for the striking reactivity difference between (E)‐ and (Z)‐1,6‐enynes using RhI‐BINAP and RhI‐TangPhos is outlined using DFT studies to provide the necessary insight for the design of new catalyst systems and the application to synthesis. 相似文献
10.
Kenichi Nomura Seijiro Matsubara Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(2):703-708
A novel rearrangement of 2‐(1‐hydroxyalkyl)‐1‐alkylcyclopropanol has been found. It proceeds in the presence of a catalytic amount of organozinc ate complex to give vic‐diols. The rearrangement can be applied to various types of 2‐(1‐hydroxyalkyl)‐1‐alkylcyclopropanol, which can be easily prepared from the corresponding α,β‐epoxyketones and bis(iodozincio)methane. When bicyclo[13.1.0]pentadecane‐1,15‐diol was treated with the organozinc ate complex, the corresponding 14‐membered cyclic vic‐diol was obtained. Thus, this rearrangement is also useful for changing the ring size of cyclic substrates. 相似文献
11.
FeCl3‐Mediated Oxidative Spirocyclization of Difluorenylidene Diarylethanes Leading to Dispiro[fluorene‐9,5′‐indeno[2,1‐a]indene‐10′,9′′‐fluorene]s
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Dr. Jian Zhao Zhanqiang Xu Dr. Kazuaki Oniwa Prof. Naoki Asao Prof. Yoshinori Yamamoto Prof. Tienan Jin 《Angewandte Chemie (International ed. in English)》2016,55(1):259-263
A novel FeCl3‐mediated oxidative spirocyclization for construction of a new class of di‐spirolinked π‐conjugated molecules, dispiro[fluorene‐9,5′‐indeno[2,1‐a]indene‐10′,9′′‐fluorene]s (DSFIIFs), has been reported. The combination of FeCl3 with FeO(OH) triggered an unprecedented double one‐electron oxidation of difluorenylidene diarylethanes to afford the corresponding dispirocycles in high yields. The highest fluorescence quantum yield was up to 0.94 in solution. This protocol is also applicable to the synthesis of the non‐spirolinked dihydroindenoindenes. 相似文献
12.
A simple and efficient approach to synthesize a novel pyrrolocoumarin 9‐hydroxy‐8H‐pyrano[3,2‐f]indol‐2‐one ( 7 ) has been described. Starting from vanillin, the key intermediate 7‐methoxy‐1H‐indol‐6‐yl propiolate ( 6 ) was synthesized in six steps. Then, the target compound was obtained by forming pyrone‐ring and demethylation simultaneously in one step. A plausible mechanism invoking PtCl4 catalyzed one‐step reaction of cyclization and demethylation was also presented. 相似文献
13.
A novel radical‐based approach for the iron‐catalyzed selective cleavage of acetal‐derived alkylsilyl peroxides, followed by the formation of a carbon–carbon bond is reported. The reaction proceeds under mild reaction conditions and exhibits a broad substrate scope with respect to the acetal moiety and the carbon electrophile. Mechanistic studies suggest that the present reaction proceeds through a free‐radical process involving carbon radicals generated by the homolytic cleavage of a carbon–carbon bond within the acetal moiety. A synthetic application of this method to sugar‐derived alkylsilyl peroxides is also described. 相似文献
14.
Enantio‐ and Diastereoselective Cyclopropanation of 1‐Alkenylboronates: Synthesis of 1‐Boryl‐2,3‐Disubstituted Cyclopropanes
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Dr. Javier Carreras Dr. Ana Caballero Prof. Dr. Pedro J. Pérez 《Angewandte Chemie (International ed. in English)》2018,57(9):2334-2338
A novel, highly enantio‐ and diastereoselective synthesis of 1‐boryl‐2,3‐disubstituted cyclopropanes has been developed by means of the cyclopropanation of alkenylboronates with ethyl diazoacetate in the presence of catalytic amounts of a chiral copper(I) complex. The products can also be directly accessed from alkynes through an operationally simple, sequential hydroboration–cyclopropanation protocol. The resulting enantioenriched 1‐boryl‐2,3‐disubstituted cyclopropanes are versatile synthetic intermediates that undergo further transformations at the carbon–boron bond. 相似文献
15.
Erzsbet Jablonkai Lszl Drahos Zbigniew Drzazga K. Michal Pietrusiewicz Gyrgy Keglevich 《Heteroatom Chemistry》2012,23(6):539-544
The addition of dialkyl phosphites, H‐phosphinates, and diphenylphosphine oxide on the β carbon atom of the not too reactive double bond of 1‐phenyl‐2‐phospholene 1‐oxide was carried out in two ways. According to the first approach (A), the P‐reagents were activated by trimethylaluminum prior to the Michael addition. The second method (B) involved the microwave(MW)‐assisted solventless reaction of the P‐species with the phospholene oxide. In general, method A was more efficient and more selective than route B. However, the addition of dialkyl phosphites and diphenylphosphine oxide could also be accomplished well under MW conditions. The disadvantage of the MW‐assisted approach is that the Michael adducts are formed as a mixture of isomers. The 3‐P⩵O‐phospholane oxides are novel products, and among these, the bis(phosphine oxide) is the precursor of the bidentate P‐ligand LuPhos. 相似文献
16.
Rhodium(II)‐Catalyzed Intramolecular Cycloisomerizations of Methylenecyclopropanes with N‐Sulfonyl 1,2,3‐Triazoles
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Kai Chen Zi‐Zhong Zhu Yong‐Sheng Zhang Dr. Xiang‐Ying Tang Prof. Min Shi 《Angewandte Chemie (International ed. in English)》2014,53(26):6645-6649
A novel rhodium(II)‐catalyzed tandem cycloisomerization of methylenecyclopropanes (MCPs) with N‐sulfonyl 1,2,3‐triazoles is disclosed. The reaction produces a series of highly functionalized polycyclic N heterocycles via a rhodium imino carbene intermediate. A distinct feature of this divergent synthesis is that different types of substrates control the reaction pathways. Moreover, several interesting transformations of these products to construct diazabicyclo[3.2.1]octane derivatives are also reported. 相似文献
17.
Mahesh Goud Bakkolla Ashok Kumar Taduri Rama Devi Bhoomireddy 《Journal of heterocyclic chemistry》2019,56(1):92-98
A novel route was developed for synthesis of high potential 1H‐tetrazoles by using conventional method. Tetrazole scaffold is a promising pharmacophore fragment, frequently used in the development of various novel drugs. Here, the novel (Z)‐3‐(N‐alkyl‐indol‐3‐yl)‐2‐(1H‐tetrazole‐5‐yl)acrylates 5 ( a – i ) have been synthesized from (Z)‐ethyl‐3‐(1H‐indol‐3‐yl)2‐(1H‐tetrazol‐5‐yl)acrylates 4 ( a – c ) by using various alkylating agents such as Dimethyl Sulphate (DMS), Diethyl Sulphate (DES), and benzyl chloride; 4 ( a – c ) were synthesized from sodium azide in the presence of copper sulfate in dimethylformamide; 3 ( a – c ) have been prepared by Knoevenagel condensation of indole‐3‐carbaldehyde 1 ( a – c ) and ethylcyanoacetate 2 in the presence of L‐Proline as a catalyst at room temperature in ethanol for an hour. This is an efficient and clean click chemistry method that has various advantages such as easy workup, higher yields, shorter reaction times, and more economical. 相似文献
18.
A variety of novel N‐t‐butyl‐N′‐aminocarbonyl‐N‐(substituted)benzoylhydrazines containing α‐aminoalkylphosphonate groups were synthesized. Treatment of α‐aminoalkylphosphonates with triphosgene yielded α‐isocyanatoalkylphosphonates, and subsequent addition with N‐t‐butyl‐N‐substituted benzoylhydrazines provided the title compounds in a one‐pot procedure with good yields. The triphosgene‐mediated reaction for the synthesis of α‐isocyanatoalkylphosphonates enjoys a number of advantages: the reaction is carried out under mild condition in good yield, triphosgene is relatively safe to handle because of its low vapor pressure and high stability, and the experimental procedure is simple. This method can be applicable to the synthesis of other α‐isocyanatoalkyl‐phosphonates and urylenediphosphonates. The structures of all of the products and by‐products were confirmed by 1H NMR, 31P NMR, IR and mass spectroscopy, and elemental analysis. We also found that some of the compounds possess potential antitobacco mosaic virus (TMV) activities and anticancer activities. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:68–72, 2001 相似文献
19.
A novel MB‐SWNT‐sol‐gel nanocomposite material was prepared by the sol‐gel process incorporating a redox mediator and carbon nanotubes. The electrocatalytic properties of the nanomaterial based sensor toward NADH oxidation were studied by electrochemical measurements. Significant enhancement of oxidation current is obtained at electrodes modified by MB‐SWNT‐sol‐gel in comparison with the analogous carbon black and/or graphite composite modified electrode. The usefulness of the nanocomposite material as a matrix for immobilizing enzymes is also demonstrated. Analytical parameters of D ‐lactate biosensors with and without SWNT in the hybrid film were compared demonstrating that performance of the biosensor was significantly improved when introducing SWNT. 相似文献
20.
KHCO3‐ and DBU‐Promoted Cascade Reaction to Synthesize 3‐Benzyl‐2‐phenylquinolin‐4(1 H)‐ones
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Haojie Ma Xiaoqiang Zhou DaiDong Wei Jinhui Cao Chong Shi Yuxing Fan Prof. Guosheng Huang 《化学:亚洲杂志》2016,11(20):2829-2833
A novel and convenient one‐pot route for the synthesis of 3‐benzyl‐2‐phenylquinolin‐4(1 H)‐ones has been developed under transition‐metal‐free conditions. This new strategy features high yield and good functional group tolerance. In addition, a proposed mechanism has been confirmed for this reaction. 相似文献