Results 91 to 100 of about 12,531 (256)

Organocatalytic Formal (3+2+1)‐Cycloaddition of Allenoates, Michael Acceptors, and Carbaldehydes

Chemistry – A European Journal, EarlyView.
The use of secondary amine Lewis base organocatalysts allows for the unprecedented activation of allenoates for formal (3+2+1)‐cycloadditions with Michael acceptors and aromatic carbaldehydes. ABSTRACT Employing secondary amines as covalently interacting Lewis basic organocatalysts allows for the activation of electron‐deficient allenes (allenoates ...
David Naderer, Alexander Pötscher, Katharina Eder, Uwe Monkowius, Markus Himmelsbach, Mario Waser   +5 more
wiley   +1 more source

Stereoretentive Nucleophilic Aromatic Substitution Accesses Atropisomeric 4‐Amino‐N‐Arylquinolinium Salts

Chemistry – A European Journal, EarlyView.
Quinolin‐4‐ones were converted to chloroquinolinium salts, allowing formation of axially chiral aminoquinolinium salts via an enantioretentive SNAr reaction with a variety of amine nucleophiles. The salts have a high rotational barrier, with a racemization half‐life of ∼1000s of years.
Darren Holmes, Nia Foster, Saima Ansari, Paul Kavanagh, Paul Dingwall, Peter C. Knipe   +5 more
wiley   +1 more source

Nitrooxylation in Organic Synthesis: From Classical Nitrate Ester Formation to Modern Catalytic Strategies

Chemistry – A European Journal, EarlyView.
Nitrooxylation—the installation of nitrate esters (–ONO2) has evolved from classical mixed‐acid protocols to catalytic and mechano‐, flow‐, photo‐, and electrochemical strategies. This review delineates ionic and radical manifolds for C–ONO2 bond formation, emphasizing mechanistic control, selected substrate scope, and selectivity.
Jayanta Dey, Dmitry Katayev
wiley   +1 more source

Stereochemical Control in the Matteson Reaction

Chemistry – A European Journal, EarlyView.
The Matteson homologation is a highly versatile method for the stereoselective insertion of carbenoids into boronic esters. Through iterative application of the process, complex chiral molecules can be synthesized. The stereoselectivity of the reaction is determined by a chiral diol incorporated in the boronic ester.
Hae Mo Lee, Christoph Hirschhäuser
wiley   +1 more source

Cyclopropylamine‐Derived Distonic Iminium Radicals: Photoinduced Strategies in Chemo‐ and Stereo‐Selective Synthesis

Chemistry – A European Journal, EarlyView.
Cyclopropylamines have emerged as powerful photocatalytic building blocks. Upon light‐induced single‐electron oxidation, they undergo strain‐release ring opening to generate distonic iminium radicals that enable diverse transformations, including ring‐opening functionalization, formal [3 + 2] cycloadditions, radical cascades, and asymmetric bond ...
Maria Chiara Cabua, Alberto Luridiana, Francesco Secci, Emanuele Cocco   +3 more
wiley   +1 more source

Chiral Pyrazolinylidene Complexes for Asymmetric Catalysis

Chemistry – A European Journal, EarlyView.
The synthesis and application of pyrazolin‐5‐ylidene NHC chiral‐at‐ruthenium catalysts is reported. The strong donating pyrazolin‐5‐ylidene ligands led to highly electron rich ruthenium complexes, which showed excellent catalytic activity and enantioselectivity in the intramolecular aziridination of an alkene.
Felix Möller, Nemrud Demirel, Thomas Krüger, Linus Plohnke, Jennifer Schröder, Sergei I. Ivlev, Eric Meggers   +6 more
wiley   +1 more source

The Mechanism of Visible‐Light Photochemical Rearrangements of Conjugated Amide Enolates

Chemistry – A European Journal, EarlyView.
Visible light irradiation of extended enolates of N‐benzylamides leads to homolytic C─N Bond cleavage, generating a biradical. Computational and mechanistic studies suggest rapid radical recombination within a solvent cage to give either ring‐expanded or rearranged products. ABSTRACT Deprotonation of conjugated amides forms colored solutions of lithium
James Mortimer, William Terry‐Wright, Basile F. E. Curchod, Jonathan Clayden   +3 more
wiley   +1 more source

Synthesis and Structures of Novel Chiral Cyclic Hypervalent Iodine(III) Reagents for Metal‐Free Ligand‐Transfer Reactions

Chemistry – A European Journal, EarlyView.
Several new chiral cyclic hypervalent iodine(III) reagents have been synthesized and characterized. Carbon‐based ligands were successfully installed onto the hypervalent iodine centers, giving thus access to novel chiral cyano‐, trifluoromethyl‐ or alkynyl‐bearing λ3‐iodanes.
Emmanuel Valzer, Jean‐Marc Sotiropoulos, Karinne Miqueu, Laurent Pouységu, Stéphane Quideau   +4 more
wiley   +1 more source

Rhodium‐Catalyzed Synthesis of Enantioenriched α‐Substituted Primary Amines Through Asymmetric Transfer Hydrogenation

Chemistry – A European Journal, EarlyView.
Enantioenriched α‐substituted primary amines are efficiently prepared by rhodium‐catalyzed asymmetric transfer hydrogenation of ortho‐hydroxyaryl N─H imines under mild conditions using a low catalyst loading and ammonium formate as the hydrogen source in high yields (up to 99%) and enantioselectivities (up to 99% ee).
Chonghuo Liu, Guillaume Lefèvre, Qin Yin, Phannarath Phansavath, Virginie Ratovelomanana‐Vidal   +4 more
wiley   +1 more source

Next‐Generation Carbon‐Based Anodes for Alkali Metal‐Ion Batteries: Recent Progress on Biphenylene and Emerging Materials

ENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
Recent advances in carbon‐based anodes for alkali metal‐ion batteries are critically reviewed, with emphasis on biphenylene and other emerging carbon allotropes. Biphenylene exhibits exceptional theoretical electrochemical properties beyond conventional graphite, highlighting its strong potential as a next‐generation anode material once scalable ...
Adewale Hammed Pasanaje, Nirpendra Singh
wiley   +1 more source