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Tetra-n-butylammonium Hydroxide:an Efficient Catalyst for N-Alkylation of Pyrimidines and Purines
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作者 ZHANG Zhi-li~ , ZHOU Shou-xin, WANG Xiao-wei, WANG Hong-tao, CHEN Yan-li and LIU Jun-yi Department of Chemical Biology, School of Pharmaceutical Sciences State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing 100083, P. R. China 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2006年第4期451-454,共4页
An efficient procedure for N-alkylation of pyrimidines and purines in the presence of tetra-n-butylammonium hydroxide(TBAH) is described. The method is very practical and the alkylation can occur at room temperature... An efficient procedure for N-alkylation of pyrimidines and purines in the presence of tetra-n-butylammonium hydroxide(TBAH) is described. The method is very practical and the alkylation can occur at room temperature and the yields of the N-alkyl pyrimidines and purines were found to be excellent. 展开更多
关键词 Tetra-n-butylammonium hydroxide n-alkylation Purine Pyrimidine
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A NEW ONE-STEP REDUCTIVE N-ALKYLATION OF AMINO ACIDS AND THEIR ESTERS
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作者 De Ling Zhou Ye Di Guan Sheng Jin Department of Chemistry,Peking University,Beijing,100871 《Chinese Chemical Letters》 SCIE CAS CSCD 1990年第3期209-210,共2页
The reductive alkylation of amine with carbonyl compounds using sodium hydrogen telluride has been investigated in recent years. Application of this method to the synthesis of N-alkyl derivatives of biologically impor... The reductive alkylation of amine with carbonyl compounds using sodium hydrogen telluride has been investigated in recent years. Application of this method to the synthesis of N-alkyl derivatives of biologically important amino acids and their esters is described. 展开更多
关键词 Ph HC STEP A NEW ONE-STEP REDUCTIVE n-alkylation OF AMINO ACIDS AND THEIR ESTERS
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Cascade N-Alkylation/Hemiacetalization for Facile Construction of the Spiroketal Skeleton of Acortatarin Alkaloids with Therapeutic Potentiality in Diabetic Nephropathy
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作者 Pei Cao Zhen-Jie Li +4 位作者 Wen-Wu Sun Shashwat Malhotra Yuan-Liang Ma Bin Wu Virinder S.Parmar 《Natural Products and Bioprospecting》 CAS 2015年第1期37-45,共9页
The concise building of the spiroketal core of acortatarin-type alkaloids as potential therapeutic agents in diabetic nephropathy was established in four steps,through a tandem N-alkylation/hemiacetalization between p... The concise building of the spiroketal core of acortatarin-type alkaloids as potential therapeutic agents in diabetic nephropathy was established in four steps,through a tandem N-alkylation/hemiacetalization between pyrrole units and the corresponding halo alcohols generated by convenient halomethylation of chiral lactones from natural aldoses. 展开更多
关键词 Acortatarin alkaloids Diabetic nephropathy n-alkylation/hemiacetalization Halomethylation Chiral lactones
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Synergistic roles of platinum nanoparticles and sodium ions within beta zeolites in N-alkylation of amines with aromatic alcohols
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作者 Yue Wu Shibo Xi +8 位作者 Cailing Chen Qizhi Hu Zhuo Xiong Jianyue Wang Yihu Dai Yu Han Shi Jiang Jun Wang Yu Zhou 《Science China Chemistry》 SCIE EI CAS CSCD 2023年第9期2690-2699,共10页
N-alkylation of amines with alcohols is a promising green route for the synthesis of N-alkylamines, but the designation of highly active and stable heterogeneous catalysts remains one challenge. In this work, we initi... N-alkylation of amines with alcohols is a promising green route for the synthesis of N-alkylamines, but the designation of highly active and stable heterogeneous catalysts remains one challenge. In this work, we initiated the application of zeolite-encapsulated noble metal nanoparticles(NPs) in the N-alkylation of amines with aromatic alcohols. Platinum(Pt) NPs were directly confined into the framework of BEA zeolite with tunable Si/Al molar ratios and Na^(+) contents. The champion catalyst afforded the extremely high turnover number(TON) of 6,176 and turnover frequency(TOF) of 3,390 h^(-1) plus stable recyclability and broad substrate compatibility. The Na ions modulated the electronic state of Pt NPs to reach a moderate Pt–H strength, which wellbalanced the two crucial steps of dehydrogenation and H-transfer and accounted for the high catalytic performance. The encapsulation of zeolites provided spatial satisfaction for the synergy effect above and enhanced the stabilization of Pt NPs. 展开更多
关键词 heterogeneous catalysis ZEOLITE AMINES n-alkylation nano catalysts
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Practical N-alkylation via homogeneous iridium-catalyzed direct reductive amination
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作者 Jing Wang Wenji Wang +3 位作者 Xiongyu Yang Jingwen Liu Haizhou Huang Mingxin Chang 《Science China Chemistry》 SCIE EI CAS CSCD 2023年第2期518-525,共8页
Direct reductive amination(DRA)is one of the most efficient methods for amine synthesis.Herein we report a practical homogeneous DRA procedure utilizing iridium catalysis.Applying simple,readily available and inexpens... Direct reductive amination(DRA)is one of the most efficient methods for amine synthesis.Herein we report a practical homogeneous DRA procedure utilizing iridium catalysis.Applying simple,readily available and inexpensive PPh_(3)and alike ligands along with iridium at a low loading,aldehydes and ketones reductively coupled with primary and secondary amines to efficiently form structurally and functionally diverse amine products,including a set of drugs and compounds from late-stage manipulation.The reaction conditions were exceptionally mild and additive-free,in which oxygen,moisture,polar protic groups and multiple other functional groups were tolerated.For targeted products,this methodology is especially versatile for offering multiple possible synthetic options.The 10 gram-scale synthesis further demonstrated the potential and promise of this procedure in practical amine synthesis.DFT studies reveal an“outer-sphere”H-addition pathway,in whichπ-πinteractions and H-bonding play important roles. 展开更多
关键词 homogeneous catalysis HYDROGENATION Iridium catalysis n-alkylation reductive amination
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Palladium-Catalyzed N-Alkylation of Amides and Amines with Alcohols Employing the Aerobic Relay Race Methodology 被引量:2
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作者 余小春 姜澜 +2 位作者 李强 谢嫒媛 徐清 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2012年第10期2322-2332,共11页
Possibly because homogeneous palladium catalysts are not typical borrowing hydrogen catalysts and ligands are thus ineffective in catalyst activation under conventional anaerobic conditions, they had not been used in ... Possibly because homogeneous palladium catalysts are not typical borrowing hydrogen catalysts and ligands are thus ineffective in catalyst activation under conventional anaerobic conditions, they had not been used in the N-alkylation reactions of amines/amides with alcohols in the past. By employing the aerobic relay race methodol- ogy with Pd-catalyzed aerobic alcohol oxidation being a more effective protocol for alcohol activation, ligand-free homogeneous palladiums are successfully used as active catalysts in the dehydrative N-alkylation reactions, giving high yields and selectivities of the alkylated amides and amines. Mechanistic studies implied that the reaction most probably proceeds via the novel relay race mechanism we recently discovered and proposed. 展开更多
关键词 palladium catalysis AMIDES AMINES ALCOHOLS n-alkylation reaction aerobic reaction relay racemethodology
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Rhodium-catalyzed aerobic N-alkylation of sulfonamides with alcohols 被引量:1
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作者 Sun Lin Feng Chuan Zhi Liu Qiang Li Xiao Chun Yu Qing Xu 《Chinese Chemical Letters》 SCIE CAS CSCD 2011年第9期1021-1024,共4页
By using the famous Wilkinson's catalyst, N-alkylation of sulfonamides can be easily realized under mild aerobic conditions by using alcohols as the alkylating reagent, giving monoalkylated sulfonamides in high yield... By using the famous Wilkinson's catalyst, N-alkylation of sulfonamides can be easily realized under mild aerobic conditions by using alcohols as the alkylating reagent, giving monoalkylated sulfonamides in high yields and selectivities with water produced as the only byproduct. This advantageous aerobic method is potentially general in substrate scope that it can also be applied to other amides, amines and alcohols. 展开更多
关键词 ALCOHOLS SULFONAMIDES Rhodium catalyst n-alkylation reaction Aerobic reaction
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Iron(lll)-Catalyzed Direct N-Alkylation of Azoles via Oxidative Transformation of sp3 C H Bonds under Solvent-Free Conditions
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作者 刘湘 陈永欣 +2 位作者 李康宁 王东 陈保华 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2012年第10期2285-2291,共7页
A new approach to synthesize N-alkylation of azoles by iron(III)-catalyst under solvent-free conditions was de- veloped. The method is broad in scope and highly efficient.
关键词 AZOLES n-alkylation SOLVENT-FREE iron catalyst C--H activation
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Direct N-alkylation of amines with alcohols using AlCl_3 as a Lewis acid 被引量:2
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作者 Ya-Qiong Li Yun-Bin Chen Zhi-Zhen Huang 《Chinese Chemical Letters》 SCIE CAS CSCD 2014年第12期1540-1544,共5页
A substitution reaction of amines with alcohols for N-alkylated amines has been developed using inexpensive AlCl3without any ligand or additive.Either aromatic or aliphatic amines and primary or secondary alcohols per... A substitution reaction of amines with alcohols for N-alkylated amines has been developed using inexpensive AlCl3without any ligand or additive.Either aromatic or aliphatic amines and primary or secondary alcohols perform the AlCl3-mediated reaction smoothly to afford various N-alkylated amines in satisfactory yields. 展开更多
关键词 Amine Alcohol n-alkylated amine Lewis acid Synthesis
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A Study on Dynamics of Drug Release from N-alkyl Chitosan Derivative Membranes In Vitro 被引量:2
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作者 LI Ming-chun~1,XIN Mei-hua~1, YAO Kang-de~2 《Chinese Journal of Biomedical Engineering(English Edition)》 2002年第3期125-132,共8页
The diffusion coefficient of model drugs (Sodium benzoate, Lysozyme and Ribonuclease) through chitosan and N-alkyl chitosan membranes were measured by using ’lag time’ technique. The results indicate that the releas... The diffusion coefficient of model drugs (Sodium benzoate, Lysozyme and Ribonuclease) through chitosan and N-alkyl chitosan membranes were measured by using ’lag time’ technique. The results indicate that the release mechanism for the drug with small molecular weight is predominantly of ’pore type’, and for the drug with high molecular weight is predominantly pf ’partition type’. The release of protein drug with higher hydrophobicity enhances as the size of N-alkyl group and its substitution degree of chitosan increase. 展开更多
关键词 n-alkylation CHITOSAN DRUG RELEASE Diffusion Coefficient
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Synthesis and antibacterial evaluation of 2-substituted-4,5-diphenyl-N-alkyl imidazole derivatives 被引量:3
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作者 Abhishek K Jain V Ravichandran +1 位作者 Madhvi Sisodiya RK Agrawal 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2010年第6期471-474,共4页
Objective:To synthesis 2-substituted-4,5-diphenyl-N- alkyl imidazole derivatives,and evaluate their antibacterial activity.Methods:A mixture of benzil(10 mmol) and ammonium acetate(0.1 mol)(immediately fused) in... Objective:To synthesis 2-substituted-4,5-diphenyl-N- alkyl imidazole derivatives,and evaluate their antibacterial activity.Methods:A mixture of benzil(10 mmol) and ammonium acetate(0.1 mol)(immediately fused) in glacial acetic acid(25 mL) was stirred at 80-100℃for 1 h under nitrogen atmosphere(to prevent incorporation of any atmospheric impurities and moisture). Substituted aldehydes(10 mmol) in glacial acetic acid(5 mL) was added drop-wise over a period of 15-20 min at the same temperature and stirred for another 4 h,the progress of the reaction was monitored by TLC test using ethyl acetate as eluent.The newly synthesized compounds were characterized by IR,<sup>1</sup>HNMR,<sup>13</sup>CNMR and by mass spectroscopy.Results:All the synthesized compounds were confirmed by spectroscopical techniques and evaluated for antimicrobial activity against Staphylococcus aureus(S.aurius),Bacilus subtilus(B.subtilus),and Escheria coli (E.coli).These compounds showed antibacterial activity(zone of inhibition) against S.aurius ranged from 3 mm to 9 mmin diameter,B.subtilus,4 -8 mm,and E.coli 5 -12 mm.Out of 2a-2e, only 2a and 2b showed some sort of activity but none of them had considerable activity compared with that of the standard.Conclusions:All the synthesized compounds show moderate activity against the tested bacteria S.aurius,B.subtilus,and E.coli.So,further structural modification is necessary to improve the antibacterial action of 2-substituted-4,5-diphenyl-N-alkyl imidazole derivatives. 展开更多
关键词 ANTIBACTERIAL activity IMIDAZOLE derivatives n-alkyl IMIDAZOLE
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Synthesis and Crystal Structure of a New N-alkylated Azacrown Ligand
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作者 XU Xin-You LUO Qin-Hui +3 位作者 NI Shi-Sheng XU Ji-De MENG Nan(Coordination Chemistry Institute, State Key Laboratory ofCoordination Chemistry Nanjing University, Nanjing 210008)ZHOU Xiang-Ge ZHOU Zhong-Yuan(Chengdu Institute of Organic Chemistry, The Chinese 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 1997年第3期195-199,共5页
A new pendant arms macrocyclic ligand, N, N'-bis(2-cyanoethyl)-3,4: 9, 10-dibenzo-1, 12-diaza-5, 8-dioxacyclopentadecane (L), was synthesized in goodyield (93% ) by alkylating 3, 4: 9, 10-dibenzo-1, 12-diaza-5, 8-... A new pendant arms macrocyclic ligand, N, N'-bis(2-cyanoethyl)-3,4: 9, 10-dibenzo-1, 12-diaza-5, 8-dioxacyclopentadecane (L), was synthesized in goodyield (93% ) by alkylating 3, 4: 9, 10-dibenzo-1, 12-diaza-5, 8-dioxacyclopentadecane(L') with acrylonitrile. Its crystal structure has been determined by X-ray diffraction.The ligand crystallizes in the orthorhombic system, space group Pbca, a=18. 143 (3),b=11. 206(2), c=22. 274(5)A, V=4528(2)A3, Mr=418. 55, Z= 8, F(000)=1792, Dc= 1. 228 gcm-3, T= 293K, μ= 7. 9 cm-1, final R=0.044 and Rw=0.067(w=1/(σ2 (F) + 0. 0005F2 ) ) based on 2291 independent reflections with F> 4. 0σ(F). The two benzene rings of the macrocyclic ligand are not in the same plane, andthe dihedral angle between them is 73. 6°, the molecule is in a folded state. 展开更多
关键词 SYNTHESIS crystal structure n-alkylated ligand AZACROWN
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Synthesis of 3-Alkyl-5-Benzylidene-2,4-Thiazolidinedione Under Microwave Irradiation
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作者 李筱芳 冯亚青 +1 位作者 张卫红 王冬慧 《Transactions of Tianjin University》 EI CAS 2003年第3期228-230,共3页
Microwave irradiation of aromatic aldehyde and 2,4-thiazolidinedione provides a fast and high-yield access to 5-benzylidene-2,4-thiazolidinedione. Seven 3-alkyl-5-benzylidene-2,4-thiazolidinedione compounds were produ... Microwave irradiation of aromatic aldehyde and 2,4-thiazolidinedione provides a fast and high-yield access to 5-benzylidene-2,4-thiazolidinedione. Seven 3-alkyl-5-benzylidene-2,4-thiazolidinedione compounds were produced with high yield by reacting 5-benzylidene-2,4-thiazolidinedione with different alkylating agents under microwave irradiation. 展开更多
关键词 benzylidene-2 4-thiazolidinedione microwave irradiation n-alkylation synthesis
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^(13)C NMR STUDIES ON DYNAMICS OF POLY (n - ALKYL METHACRYLATES)
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作者 晏欣 王德华 钱保功 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1991年第4期314-317,共4页
The dynamics of a series of poly(n-alkyl methacrylates) is investigated by means of ^(13)C spin-lattice relaxation experiments. The results show that the dynamics has the polymer property dependence.
关键词 ^(13)C Spin-Lattice Relaxation DYNAMICS Poly (n-alkyl methacrylates)
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Analogs of Antifungal Indoles Isolated from Aporpium Caryae with Activity Against Sudden-Death Syndrome of Soybean
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作者 Brenda Bertinetti Mercedes Scandiani Gabriela Cabrera 《American Journal of Plant Sciences》 2011年第2期245-254,共10页
Based on the precedent discovery of a weak antifungal indole isolated from Aporpium caryae, which increased its activity when changing the N-alkyl chain, nineteen N-alkyl indoles, with alkyl chains from one to ten car... Based on the precedent discovery of a weak antifungal indole isolated from Aporpium caryae, which increased its activity when changing the N-alkyl chain, nineteen N-alkyl indoles, with alkyl chains from one to ten carbons and one or two hydroxyls, one amine or bromine functional groups, were prepared and fully characterized by spectroscopic methods. The aim of this study is the search for new synthetic agrochemical leads derived from natural products. The antifungal activity of the synthesized compounds against three fungal strains was measured in vitro. Six compounds presented good activity against Fusarium virguliforme, the causal agent of sudden-death syndrome (SDS) in soybean, in a bioautography assay. Four of them were tested in a germination test and in a greenhouse experiment. All tested compounds, applied as seed treatment, showed antifungal properties being effective to control SDS when there was low level of fungal contamination. Results indicate that some of the tested compounds are acting as growth inhibitors and represent new leads for the treatment of SDS for which no specific treatment has been previously reported. 展开更多
关键词 n-alkyl INDOLE SOYBEAN PHYTOPATHOGEN Fusarium Virguliforme Sudden-Death SYNDROME
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Iron-nickel alloy particles with N-doped carbon “armor” as a highly selective and long-lasting catalyst for the synthesis of Nbenzylaniline molecules
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作者 Gang Wang Longchao Sun +2 位作者 Wanyi Liu Haijuan Zhan Shuxian Bi 《Nano Research》 SCIE EI CSCD 2024年第4期2308-2319,共12页
A scalable strategy for the convenient and rapid preparation of nitrogen-doped carbon-coated iron-based alloy catalysts was developed.By controlling the type and amount of metal salts in the precursor,various types of... A scalable strategy for the convenient and rapid preparation of nitrogen-doped carbon-coated iron-based alloy catalysts was developed.By controlling the type and amount of metal salts in the precursor,various types of nitrogen-doped carbon-coated alloy catalysts can be prepared in a targeted manner.Fe_(2)Ni2@CN materials with small particle sizes and relatively homogeneous basic sites showed promising results in the N-alkylation reaction of benzyl alcohol with aniline(optimum yield:99%).It is worth noting that the catalyst can also be magnetically separated and recovered after the reaction,and its performance can be regenerated through simple calcination.Furthermore,it was confirmed by kinetic experiments that the activation of C–H at the benzyl alcohol benzylic position is the rate-determining step(RDS).According to density flooding theory calculations,Fe_(2)Ni2@CN catalysts require less energy than other materials(Fe@CN and Ni@CN)for the RDS(dehydrogenation reaction)process.Therefore N-alkylation reactions are more easily carried out on Fe_(2)Ni2@CN catalysts,which may be the reason for the best catalytic activity of Fe-Ni alloy materials.These carbon-coated alloy materials will show great potential in more types of heterogeneous catalysis. 展开更多
关键词 iron-nickel alloy catalyst n-alkylation reaction magnetic separation reaction path dehydrogenation reaction
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Tuning the Johari-Goldstein β-Relaxation and Its Separation from α-Relaxation of Poly(n-alkyl methacrylate)s by Small Molecule-bridged Hydrogen Bonds
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作者 Yuan-Biao Liu Gao-Peng Shi Guo-Zhang Wu 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2021年第11期1459-1469,共11页
Introducing small molecule-bridged hydrogen bonds(HBs)between polymer chains has been reported to effectively reduce the interchain cooperativity despite of strengthening the intermolecular interaction.Here,a systemat... Introducing small molecule-bridged hydrogen bonds(HBs)between polymer chains has been reported to effectively reduce the interchain cooperativity despite of strengthening the intermolecular interaction.Here,a systematic investigation on tuning the Johari-Goldsteinβ(βJG)relaxation by adding various low-molecular-weight phenols in poly(n-alkyl methacrylate)s is carried out to further clarify the anomalous dynamics.Given these small molecules capable of coupling the motion with pendent groups of host polymers due to forming at least two HBs per molecule,poly(n-alkyl methacrylate)mixtures exhibit rich dynamic changes in theβJG-properties andα,βJG separations.An increased loading of phenols with a small size and strong inter-HB strength(Δυi)clearly benefits for significant retardation and suppression of theβJG-relaxation,narrows theα,βJG separation and converges theβJG-peak with theα-peak,which demonstrates the alleviation of inter-chain topological constraints.However,small molecules with a relatively big size and weakΔυi are found to amplify the magnitude of theα,βJG separation of poly(butyl methacrylate),even though experimental results of changes inα-dispersion and dynamic fragility confirm a reduction of the coupling factor n in all of these hybrids.The counterintuitive phenomenon suggests that the crossover time tc in the Coupling Model is no longer a universal quantity if the inter-chain interaction of polymers is strengthened by HBs.These compelling findings shed vital insights into the HBinduced anomalous dynamics,and provide essential guidance for tailoring theβJG behavior and designing glassy polymeric materials. 展开更多
关键词 Johari-Goldsteinβ-relaxation Hydrogen bond Glass transition Poly(n-alkyl methacrylate) Small molecule
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Limited Fraction of Crystallized Side Chains in Bottlebrush Poly(n-alkyl methacrylate)s
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作者 Ming-Yue Xiang Dong Lyu +1 位作者 Ling-Zhi Liu Yong-Feng Men 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2021年第9期1211-1216,共6页
Crystallinity of bottlebrush polymers due to side chain crystallization has been considered to be related to the length of the side chains only under the assumption of complete participation of crystallization by all ... Crystallinity of bottlebrush polymers due to side chain crystallization has been considered to be related to the length of the side chains only under the assumption of complete participation of crystallization by all sidechains.Recent experimental results revealed that in poly(n-alkyl methacrylate)s a fraction of side chains could not crystallize due to constraints imposed by the trapped main chain entanglements and required expansi on of main chain-main chain distanee.This result renders the original simplified con sideration of the origin of crystallinity in bottlebrush polymers questionable.In this work,we introduce a new parameter f_(c),the fraction of crystallizable side chains,to better describe the crystallinity of bottlebrush polymers.A lin earrelati on ship between the meltingenthalpy and the number of alkyl groups in side chains for bottlebrush polymers reported repeatedly indicates that f_(c) remains essentially unchanged when bottlebrush polymers had the same main chain structure and grafting degree but different side chain lengths.The slope of the above-mentioned linear relationship is thus △H_(CH2)xf_(c),where △H_(CH2) stands for the melting enthalpy of one mole alkyl group packed into the crystal.With a known value of f_(c),it is possible to estimate the value of △H_(CH_(2)).In case of poly(n-alkyl methacrylate)s,we estimated △H_(CH_(2)) of hexagonal crystal being at most 5.74 kJ/mol with the knowledge of possibly smallest f_(c) of 0.67 obtained from small angle X-ray scattering data.Therefore,the crystallinity of bottlebrush polymer would be calculated based on the equati on X_(c)=f_(c)×N_(c)/N with N and N_(c) being the nu mber of alkyl groups in a side chain and those packed in the crystalline structure,respectively.Both chemical structure and grafting degree of bottlebrush polymers affect f_(c). 展开更多
关键词 Poly(n-alkyl methacrylate)s(PMA(n)s) PMA(n)-co-PMMA Crystallization behavior The fraction of crystallizable side chain(fc) Grafting degree(G)
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Synthesis of chiral N-alkylated indoles through replacement of aniline nitrogen by natural amino acids
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作者 Xiaohua Li Weiyi Wang +2 位作者 Qiuqin He Yin Liu Renhua Fan 《Green Synthesis and Catalysis》 2022年第3期282-286,共5页
Chiral N-alkylated indoles are privileged structural motifs found in many natural products and pharmaceuticals and a search for effective methods with which to prepare chiral N-alkylated indoles is ongoing.Efficient s... Chiral N-alkylated indoles are privileged structural motifs found in many natural products and pharmaceuticals and a search for effective methods with which to prepare chiral N-alkylated indoles is ongoing.Efficient syntheses of enantioenriched N-alkylated indoles has been developed but not with standing these advances,the develop-ment of a facile method to prepare chiral N-alkylated indoles from simple and available starting materials under mild conditions is still needed.In this paper,we report a nitrogen replacement process driven by dearomatization that directly incorporates naturalα-amino acids into 2-alkynylanilines leading to the formation of a variety of multi-functional chiral N-alkylated indoles. 展开更多
关键词 Chiral n-alkylated indoles Nitrogen replacement DEAROMATIZATION 2-Alkynylanilindes Naturalα-amino acids
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Strong dual-state emission of unsymmetrical and symmetrical thiazolothiazole-bridged imidazolium salts 被引量:1
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作者 Puhui Xie Ying Zhou +5 位作者 Xiaochuan Li Xiaojing Liu Lijie Liu Zhanqi Cao Jianji Wang Xin Zheng 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第3期415-418,共4页
A novel thiazolothiazole-bridged imidazole derivative(1) was found to exhibit blue fluorescence in gaseous state or in methanol and yellow fluorescence in solid state. The N-alkylation of imidazole subunit(s) in 1 usi... A novel thiazolothiazole-bridged imidazole derivative(1) was found to exhibit blue fluorescence in gaseous state or in methanol and yellow fluorescence in solid state. The N-alkylation of imidazole subunit(s) in 1 using n-propyl iodide generated unsymmetrically or symmetrically alkylated thiazolothiazolebridged imidazolium salts with good water solubility and remarkably strong emission in solution. Furthermore, the replacement of iodide counter-anion by triflate or bis(trifluoromethane sulfonyl)imide achieved remarkably strong emission in solid state and in solution as well as good water solubility. The strong fluorescence of dicationic salts with triflate and NTf_(2)^(-)counter-anions in solid state can be ascribed to their twisted and rigid structures induced by interionic C-H···F hydrogen bonding. 展开更多
关键词 Dual-state fluorescence Unsymmetrical TTz-bridged imidazolium Water solubility n-alkylation of imidazole Twisted and rigid structures
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