Results 221 to 230 of about 804,715 (287)

Enantioselective Photochemical Generation of a Short‐Lived, Twisted Cycloheptenone Isomer: Catalytic Formation, Detection, and Consecutive Chemistry

Angewandte Chemie International Edition, Accepted Article.
Cyclohept‐2‐enone‐3‐carboxylic acid undergoes a photochemical isomerization from its cis‐ to its trans‐form either upon direct irradiation (λ = 366 nm) or in the presence of a triplet sensitizer (λ = 459 nm). The intermediate chiral trans‐isomer was detected by step‐scan FTIR displaying a lifetime of 107 ms (r.t., CH2Cl2). Ensuing Diels‐Alder reactions
Max Stierle, Constantin Jaschke, Daniel Grenda, Martin Peschel, Thomas Pickl, Niklas Gessner, Patrick Nuernberger, Benjamin Fingerhut, Christian Ochsenfeld, Regina de Vivie-Riedle, Thorsten Bach   +10 more
wiley   +1 more source

Identification of an Activity Selector for the Nitroso‐Forming Activity in Bacterial Type‐III Copper Enzymes

Angewandte Chemie International Edition, Accepted Article.
O‐aminophenol oxidases, a specialized subclass of type‐III copper proteins, play a crucial role in the biosynthesis of bioactive nitrosophenols which display antiretroviral and blood cholesterol lowering activity. Another related subclass of type‐III copper proteins, tyrosinases, closely resemble o‐aminophenol oxidases both structurally and ...
Hoa Le Xuan, Felix Panis, Annette Rompel
wiley   +1 more source

Open Access Journals / Institutional Repositories [PDF]

, 2008
Düpow, Heidi, Finke, Angelika, Schmidt, Barbara   +2 more
core   +1 more source

α‐Amination of 1,3‐Dicarbonyl Compounds and Analogous Reactive Enolate‐Precursors Using Ammonia Under Oxidative Conditions

Angewandte Chemie International Edition, Accepted Article.
We herein introduce a method for the direct a‐amination of different carbonyl compounds by employing aqueous ammonia as the N‐source. Upon using NH3 in combination with hypochlorites as simple oxidants under phase‐transfer catalytic conditions it is possible to carry out the direct a‐amination of reactive enolate‐precursors such as cyclic b‐ketoesters,
Christopher Mairhofer, Katharina Röser, Gabriel Burel, Sarah Merzinger, Jean-François Brière, Roland Obermüller, Mario Waser   +6 more
wiley   +1 more source

Photocatalytic Generation of a Ground‐State Electron Donor through Water Activation

Angewandte Chemie International Edition, Accepted Article.
Electron donors that can be excited to higher energy states through light absorption can achieve oxidation potentials as low as ‐3.0 V (vs. SCE). However, ground‐state organic electron transfer reagents operating at such potentials remain underdeveloped, often necessitating multi‐step syntheses and elevated reaction temperatures for activation.
Maxim-Aleksa Wiethoff, Lena Lezius, Armido Studer   +2 more
wiley   +1 more source

Leveraging Non‐Covalent Interactions for the Binding of CO by a Weakly Lewis Acidic Borane

Angewandte Chemie International Edition, Accepted Article.
Known boron carbonyl complexes either exploit very high Lewis acidity or a low oxidation state boron centre in order to capture CO. By contrast, we report a carbonyl complex featuring a simple tri‐coordinate borane, characterized by a Lewis acidity which is only marginally higher than B(NMe2)3.
Agamemnon Crumpton, Caitilín McManus, Simon Aldridge   +2 more
wiley   +1 more source

The Flexibility of Tetra(N‐Heterocyclic Carbene) Ligands Controls the Nuclearity and Geometry of Polynuclear MI‒NHC Assemblies

Angewandte Chemie International Edition, Accepted Article.
A series of tetrakisimidazolium salts bearing two di(phenylimidazolium)amine groups linked by differently substituted anthracenes has been prepared. These are H4‐1a(PF6)4 (anthracene bridge), H4‐1b(PF6)4 (phenyl‐anthracene‐phenyl bridge), H4‐1c(PF6)4 (anthracene‐phenyl bridge) and H4‐1d(PF6)4 (anthracene‐phenyl‐anthracene bridge). X‐ray crystallography
Guang-Feng Jin, Fang Wang, F. Ekkehardt Hahn, Ying-Feng Han   +3 more
wiley   +1 more source

Allenylidene Phosphonium Ion: An Isoelectronic Phosphorus Analogue of [3]Cumulene

Angewandte Chemie International Edition, Accepted Article.
Herein we disclose the synthesis, characterization and bonding analysis of a crystalline allenylidene phosphonium ion ([R2P=C=C=CAr2]+) [2]+ (R = 1,3‐diisopropylphenylimidazolin‐2‐ylidenamino, CAr2 = 9‐fluorenylidene), an isolobal analogue of [3]cumulenes. The cation was prepared via methoxide ion abstraction of an alkynyl phosphine 1.
Lucas C. Torres, Pawel Löwe, Avik Bhattacharjee, Maike B. Röthel, Michael Seidl, Jesse LeBlanc, Klaus Wurst, Fabian Dielmann, Christopher Blain Caputo   +8 more
wiley   +1 more source

Decoding Variants of Pyrite, Arsenopyrite and Marcasite Using an Electron Counting Rule

Angewandte Chemie International Edition, Accepted Article.
Pyrite, Marcasite and Arsenopyrite are of significant historical and contemporary interest. Compounds adopting these structure types are extensively studied for their crystallographic properties and potential applications in energy storage and conversion.
Dirk Johrendt, Kristian Witthaut, Sandra Kreiner   +2 more
wiley   +1 more source

Late‐stage cross‐electrophile coupling of arylthianthrenium salts with (hetero)aryl (pseudo)halides via palladium catalysis

Angewandte Chemie International Edition, Accepted Article.
Herein, we present a cross‐coupling reaction of arylthianthrenium salts at a late stage with diverse (hetero)aryl (pseudo)halides under reductive conditions, in which a palladium(0) catalyst differentiates between two aryl electrophiles based on the different rates of oxidative addition of arylthianthrenium salts and aryl halides for selective umpolung.
Yuanhao Xie, Li Zhang, Tobias Ritter
wiley   +1 more source