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Marcus Frings Iuliana Atodiresei Dr. Jan Runsink Dr. Gerhard Raabe Prof. Dr. Carsten Bolm Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(7):1566-1569
In control : A new catalytic vinylogous Mukaiyama aldol reaction provides products with high diastereo‐ and enantioselectivities (up to 99 % de and ee; see scheme). The relative and absolute stereochemistry of a representative product was rigorously assigned by NMR and CD spectroscopies (measured and calculated), X‐ray diffraction, and quantum‐chemical calculations.
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Tetyana Beryozkina Dr. Ksenia Boyko Natalya Khanduyeva Volodymyr Senkovskyy Dr. Marta Horecha Ulrich Oertel Dr. Frank Simon Dr. Manfred Stamm Prof. Anton Kiriy Dr. 《Angewandte Chemie (International ed. in English)》2009,48(15):2695-2698
Graft work : The first surface‐initiated and site‐specific palladium‐catalyzed Suzuki polycondensation that allows selective grafting and patterning of semiconducting and emissive poly[9,9‐bis(2‐ethylhexyl)fluorene] ( 1 ) at room temperature is developed (see scheme). The pattering is demonstrated by AFM (see image).
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Giuseppina Pace Dr. Artur Stefankiewicz Jack Harrowfield Prof. Jean‐Marie Lehn Prof. Paolo Samorì Prof. 《Chemphyschem》2009,10(4):699-705
On edge : Self‐assembled monolayers of a bis(hydrazone)‐based molecular grid physisorbed on graphite are studied by scanning tunneling microscopy (see picture). High order is attained at the supramolecular level by thermal annealing of the grid‐based films. A preferential edge‐on configuration of the molecular grid with respect to the substrate is found.
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Zhiyong Jiang Dr. Yuanyong Yang Yuanhang Pan Yujun Zhao Hongjun Liu Choon‐Hong Tan Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(19):4925-4930
Constructing α‐stereogenic amides and ketones : The highly regioselective and enantioselective conjugate addition of 1,3‐dicarbonyl compounds to 1,4‐dicarbonyl but‐2‐enes has been developed with the chiral bicyclic guanidine as catalyst (ee values up to 97 %; see scheme).
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Many components make light work : A novel synthetic strategy for the preparation of pyridines and isoquinolines in high chemo‐ and regioselectivity has been developed. By manipulating the reaction conditions, either product can be generated smoothly in a highly efficient and atom‐economic manner (see scheme).
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Jason L. Dutton Heikki M. Tuononen Adjunct Prof. Dr. Paul J. Ragogna Prof. 《Angewandte Chemie (International ed. in English)》2009,48(24):4409-4413
Te for two : Supported by pyridine‐ or carbene‐based ligands, tellurium‐centered dications are prepared in high yield and include a dicationic tellurium analogue of the recently synthesized “carbodicarbene”. The key to accessing these compounds is the isolation of a base‐stabilized form of TeOTf2 (see structure), a new highly electrophilic reagent for tellurium chemistry.
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Hiromitsu Maeda Prof. Dr. Yoshihiro Ito Yohei Haketa Nazuki Eifuku Eunji Lee Myongsoo Lee Prof. Dr. Takeshi Hashishin Dr. Kenji Kaneko Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(15):3706-3719
Just subtract water : Amphiphilic π‐conjugated acyclic oligopyrroles form solvent‐assisted H‐aggregates that give rise to vesicular structures in aqueous solution (see figure). The H‐aggregates are sensitive to the conditions and are transformed into J‐aggregates by the removal of water.
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Andrey A. Fokin Prof. Dr. Boryslav A. Tkachenko Dr. Natalie A. Fokina Dr. Heike Hausmann Dr. Michael Serafin Dr. Jeremy E. P. Dahl Dr. Robert M. K. Carlson Dr. Peter R. Schreiner Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(15):3851-3862
Functionalized nanodiamonds : Various functional groups have been incorporated into the structures of the naturally occurring diamondoids [1(2)3]tetramantane and [12312]hexamantane (cyclohexamantane), which represent hydrogen‐terminated prism‐shaped nanodiamonds (see picture). The attachment points define the use of these diamond‐like molecules as geometric building blocks for a variety of applications.
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Toshihide Maki Dr. Shinya Iikawa Gen Mogami Hitomi Harasawa Yoshihiro Matsumura Prof. Dr. Osamu Onomura Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(21):5364-5370
Get selective! A selective oxidation of 1,2‐diols to α‐hydroxyketones catalyzed by organotin compounds has been developed (see scheme). Invaluable chemo‐ and stereoselectivity were found in the reaction. The catalytic system has been achieved by electrochemical and chemical oxidation.
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Jiaobing Wang Dr. Yanfei Shen Dr. Stefanie Kessel Dr. Paulo Fernandes Dr. Kaname Yoshida Dr. Shiki Yagai Dr. Dirk G. Kurth Prof. Helmuth Möhwald Prof. Takashi Nakanishi Dr. 《Angewandte Chemie (International ed. in English)》2009,48(12):2166-2170
Fullerene flakes : A diacetylene‐functionalized fullerene derivative self‐organizes into flakelike microparticles (see picture). Both the diacetylene and C60 moieties can be effectively cross‐linked, which leads to supramolecular materials with remarkable resistivity to solvent, heat, and mechanical stress. Moreover, the surface of the cross‐linked flakelike objects is highly durable and water‐repellent.
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Size matters: Nanometer‐sized gaps in aggregates of silver nanoparticles are generated by covering the nanoparticle surface with a bilayer of cetyltrimethylammonium bromide. The nanometer‐ to micrometer‐sized wells are lithographically generated on polydimethylsiloxane surfaces. The wells filled with the modified nanoparticles (see picture) and the effect of the aggregate size on SERS enhancement are investigated.
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Ping‐Chen Lee Po‐Yu Tsai Ming‐Kai Hsiao King‐Chuen Lin Prof. C. H. Huang A. H. H. Chang Prof. 《Chemphyschem》2009,10(4):672-679
A process of elimination : Optical spectra of the Br2 product eliminated from the photodissociation of 1,1‐dibromoethylene at 248 nm are obtained (see picture), and the subsequent dissociation pathways are proposed with the aid of ab initio potential energy calculations. The behavior of the compound is compared with that of 1,2‐dibromoethylene.
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Yoshiki Morimoto Prof. Dr. Tatsuya Okita Hitomi Kambara 《Angewandte Chemie (International ed. in English)》2009,48(14):2538-2541
The proof of the pudding : The first asymmetric total synthesis of the marine tetracyclic oxasqualenoid (+)‐omaezakianol features a convergent olefin cross‐metathesis between a monotetrahydrofuran fragment and a triepoxy alkene, and cascade oxacyclizations of a triepoxy alcohol to form the right‐hand three ether rings. The total synthesis proved the absolute configuration of (+)‐omaezakianol to be that shown.
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Nicolas Marion Dr. Gilles Lemière Andrea Correa Chiara Costabile Rubén S. Ramón Xavier Moreau Dr. Pierre de Frémont Dr. Rim Dahmane Alexandra Hours Dr. Denis Lesage Jean‐Claude Tabet Prof. Dr. Jean‐Philippe Goddard Dr. Vincent Gandon Dr. Luigi Cavallo Prof. Dr. Louis Fensterbank Prof. Dr. Max Malacria Prof. Dr. Steven P. Nolan Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(13):3243-3260
Ester‐way to heaven : Unexpected formation of bicyclo[3.1.0]hexene 4 was the main focus of combined experimental and theoretical studies on the Au‐catalyzed cycloisomerization of branched dienyne 1 (see scheme), which provided better understanding of the mechanistic details governing the cyclization of enynes bearing a propargylic ester group.
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Wangyang Tu Paul E. Floreancig Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(25):4567-4571
Macrocyclic oxocarbenium ions can be formed from macrolactones that contain benzylic or allylic ether groups through oxidative carbon–hydrogen‐bond activation mediated by 2,3‐dichloro‐4,5‐dicyanoquinone (DDQ). The applicability of this efficient reaction to complex‐molecule synthesis was demonstrated by its use in a brief formal synthesis of neopeltolide (see retrosynthetic scheme) to form the tetrahydropyrone ring.
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Keith Huynh Dr. Joan Vignolle Dr. T. Don Tilley Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(16):2835-2837
Zirconocene is the key : A new synthetic method, which utilizes zirconocene‐mediated coupling of alkynes, has been developed for the preparation of a new class of highly Lewis acidic boroles (see scheme). Such compounds hold potential for applications in catalysis and the field of electron‐deficient organic materials.
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Network formation: Comicellization of polystyrene‐block‐polyethylene oxide (PS–PEO) with non‐ionic surfactants leads to the formation of networks and chains of spheres. The aqueous network solutions are responsive to dilution, undergoing morphological transformations to cylinders with Y junctions and both two‐ and three‐dimensional toroids (see figure).