共查询到20条相似文献,搜索用时 898 毫秒
1.
Michael Printz Dr. Clemens Richert Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(14):3390-3402
Effect of a PAH on base pairing : A polycyclic aromatic hydrocarbon (PAH) covalently linked to the N6‐position of a dangling deoxyadenosine residue (see scheme) of an oligonucleotide increases target affinity, but decreases base‐pairing selectivity. Melting point increases of up to 28 °C (14 °C per residue) were observed, and 20 out of 24 mismatch‐containing duplexes are stabilized more strongly by the PAH substituent than their perfectly matched counterpart.
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Niels Elders Eelco Ruijter Dr. Frans J. J. de Kanter Dr. Elwin Janssen Martin Lutz Dr. Anthony L. Spek Prof. Dr. Romano V. A. Orru Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(25):6096-6099
Diversity‐oriented synthesis : The multicomponent reaction of α‐isocyano amides, aldehydes or ketones, and amines affords N‐(cyanomethyl)amides, presenting the fourth class of products from this combination of reagents (see scheme). The scope of the reaction is very broad and various functional groups are tolerated. The outcome of the reaction can also be directed to the formation of 2H‐2‐imidazolines by AgI catalysis.
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Alexis Coste Ganesan Karthikeyan Dr. François Couty Prof. Gwilherm Evano Dr. 《Angewandte Chemie (International ed. in English)》2009,48(24):4381-4385
Mild reaction conditions are the advantage of the title reaction, which allows straightforward entry to a variety of ynamides starting from readily available 1,1‐dibromo‐1‐alkenes, which act as attractive alkynylating agents (see scheme; EWG=electron‐withdrawing group, DMF=N,N‐dimethylformamide).
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Mikhail V. Rekharsky Dr. Hatsuo Yamamura Prof. Tadashi Mori Prof. Akihiro Sato Dr. Motoo Shiro Dr. Sergey V. Lindeman Dr. Rajendra Rathore Dr. Kouhei Shiba Dr. Young Ho Ko Dr. Narayanan Selvapalam Dr. Kimoon Kim Prof. Yoshihisa Inoue Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(8):1957-1965
Water seeds : Complex stoichiometry/composition and degree of oligomerization (oligomeric supramolecular complex formation) of cucurbit[6]uril (CB[6]) with N‐alkyl‐ and N,N′‐dialkylpiperazine were investigated in aqueous solutions by means of isothermal titration calorimetry (ITC), ESI‐MS, NMR and light scattering measurements.
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Saikat Mandal Dr. Atsuomi Shundo Dr. Somobrata Acharya Dr. Jonathan P. Hill Dr. Qingmin Ji Dr. Katsuhiko Ariga Dr. 《化学:亚洲杂志》2009,4(7):1055-1058
Keeping their cool : Fabrication of a 2D weblike nanonetwork of gold was successfully demonstrated through a two‐step procedure including complexation of gold precursors to a weblike supramolecular assembly of surfactant followed by in situ reduction of the precursors to gold. Molecular assemblies stabilized by hydrogen bonding provided a sound template, leading to the highly integrated structure of gold through room‐temperature (cold) nanostructure fusion.
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Nadine Rosenberger Armido Studer Prof. Dr. Nobuyuki Takatani Dr. Hiroshi Nakajima Dr. Yoshihito Watanabe Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(11):1946-1949
Searching for “intelligence” : Azurin–PNIPAM conjugates were prepared by site‐directed mutagenesis followed by protein reconstitution by using imidazole‐conjugated poly(N‐isopropylacrylamides). The polymer‐bound imidazole acts as a ligand in the active site of the blue copper protein azurin. The bioconjugates showed thermosensitive behavior in electron‐transfer processes with reduced cytochrome c.
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Under Lewis acid condition, N‐methyl‐3‐phenyl‐N‐(2‐(Z)‐phenylethenyl)‐cis‐oxiranecarboxamide undergoes elegant double cyclizations to give interesting products. 相似文献
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Yann Ferrand Dr. Emmanuel Klein Dr. Nicholas P. Barwell Matthew P. Crump Dr. Jesus Jiménez‐Barbero Prof. Cristina Vicent Dr. Geert‐Jan Boons Prof. Sampat Ingale Anthony P. Davis Prof. 《Angewandte Chemie (International ed. in English)》2009,48(10):1775-1779
Changing employment : Receptor 1 binds β‐N‐acetylglucosaminyl (β‐GlcNAc) up to 100 times more strongly than it does glucose. This synthetic lectin shows affinities similar to wheat germ agglutinin (WGA), a natural lectin used to bind GlcNAc. Remarkably, 1 is more selective than WGA. It favors especially the glycoside unit in glycopeptide 2 , a model of the serine‐O‐GlcNAc posttranslational protein modification.
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Katsunori Tanaka Dr. Yohei Fujii Hiroomi Tokimoto Dr. Yasutaka Mori Shin‐ichi Tanaka Dr. Guang‐ming Bao Eric R. O. Siwu Dr. Aiko Nakayabu Koichi Fukase Prof. Dr. 《化学:亚洲杂志》2009,4(4):574-580
On solid ground : A new solid‐phase synthesis of N‐linked glycans featuring 1) highly stereoselective β‐mannosylation and microfluidic α‐sialylation and 2) efficient glycosylation of the N‐phenyltrifluoroacetimidate units on JandaJel resin is reported. Reagent concentration effects by a fluorous solvent are effectively applied, and the use of these methods results in the first synthesis of a sialic acid containing complex‐type N‐glycan on a solid support.
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Hai‐Hua Lu Hui Liu Dr. Wei Wu Xu‐Fan Wang Liang‐Qiu Lu Wen‐Jing Xiao Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(12):2742-2746
Economical approach : The first organocatalytic asymmetric intramolecular hydroarylation of phenol‐ and aniline‐derived enals offers one of the most straightforward and atom‐economic approaches to enantioriched chromans and tetrahydroquinolines (up to 96 % ee; see scheme).
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A convenient route with high stereo control to γ‐acetoxy dienoates is provided by the reaction of methyl propiolate with aldehydes in the presence of ZnEt2 and N‐methylimidazole at room temperature, followed by the catalytic conversion of the resulting γ‐hydroxy‐α,β‐acetylenic esters with p‐N,N‐dimethylaminopyridine (DMAP) in acetic anhydride (see scheme).
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Yanqing Zhang Zuliang Chen Yuanjing Xiao Dr. Junliang Zhang Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(21):5208-5211
Efficient route : A novel RhI‐catalyzed regio‐ and stereospecific carbonylation reaction of (1‐alkynyl)cyclopropyl ketones by selective activation of a carbon? carbon σ bond of the cyclopropane ring was demonstrated (see scheme). This method provides a general, efficient, stereoselective route to synthesise 1,3,5‐trisubstituted and 1,3,5,6‐tetrasubstituted 5,6‐dihydrocyclopenta[c]furan‐4‐one with convertible functional groups.
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Thomas K. Wood Warren E. Piers Brian A. Keay Masood Parvez 《Angewandte Chemie (International ed. in English)》2009,48(22):4009-4012
2009: A boraanthracene odyssey : General routes to boraanthracene derivatives—long proposed, but never observed—are disclosed, along with the structural and photophysical properties of these compounds and their remarkable reactivity towards oxygen.
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Xavier Guinchard Dr. Xavier Bugaut Cyril Cook Emmanuel Roulland Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(23):5793-5798
Original and ambivalent : We describe the preparation of a series of new potassium trifluoroborates 1 , and the study of their behaviour in a Pd0‐catalyzed cross‐coupling reaction. We found that compounds 1 are endowed with original properties as they behave as nucleophilic cross‐coupling partners chemoselectively, but also as ambivalent synthons. The usefulness of this methodology has been successfully illustrated by the first total synthesis of an N‐acyl spermidine.
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François Robert Anil D. Naik Dr. Bernard Tinant Prof. Dr. Raphaël Robiette Dr. Yann Garcia Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(17):4327-4342
All light and no heat? Structure–property relationships for photochromic and thermochromic N‐salicylideneanils have been revised (see picture). One derivative has a packed crystal structure, is photochromic and exhibits an infinitely slow thermal back relaxation of technological interest. Complexation of the anils to transition metals has also been studied.
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Jun Shi Hiroki Shigehisa Dr. Carlos A. Guerrero Ryan A. Shenvi Chuang‐Chuang Li Dr. Phil S. Baran Prof. 《Angewandte Chemie (International ed. in English)》2009,48(24):4328-4331
One stereocenter makes all the difference : The synthesis and biological evaluation of 17‐epi‐cortistatin A is reported from a common intermediate used to procure natural cortistatin A. The synthesis features a unique stereocontrolled Raney‐Ni reduction process that can be employed to reliably produce both α‐ and β‐configured D‐ring aryl steroids. Biological evaluations of these “cortalogs” are reported for the first time.
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Gregory A. Chass Dr. Christopher J. O'Brien Dr. Niloufar Hadei Dr. Eric Assen B. Kantchev Dr. Wei‐Hua Mu De‐Cai Fang Prof. Alan C. Hopkinson Prof. Imre G. Csizmadia Prof. Michael G. Organ Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(17):4281-4288
Why bigger is better : A “steric wall” created by the N‐(2,6‐diisopropylphenyl) substituent on the bulky NHC ligand IPr (1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene) guides the reactants to and from the Pd center through weak, fleeting (IPr)H–Pd interactions that help the oxidative addition intermediate escape “the anti‐trap”. The alternative “side” approach leads to transmetalation (the rate‐limiting step) for which a novel Pd–Zn interaction was identified.
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Lars K. Ottesen Christian A. Olsen Dr. Matthias Witt Dr. Jerzy W. Jaroszewski Prof. Henrik Franzyk Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(12):2966-2978
Robust protocol! A diverse array of piperazine scaffolds was obtained by a robust solid‐phase‐synthesis protocol involving multistep elaboration of a resin‐bound aziridine (see scheme). Microwave‐assisted on‐resin protectinggroup introduction and manipulation as well as intramolecular Fukuyama–Mitsunobu cyclization conditions were key features.