Results 61 to 70 of about 2,457 (204)

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

How Amino Acids Intercalate in CaFe Layered Double Hydroxides: A Combined RIXS and NEXAFS Study

ChemPhysChem, Volume 26, Issue 6, March 15, 2025.
Intercalation of amino acids in layered double hydroxides offers a road to functional (bio)catalysts. With resonant soft x‐ray spectroscopy we probe the electronic structure of these systems and observe activation and passivation of electronic states as well as bond formation between the amino acid and the LDH upon intercalation.
R. Büchner, A. Born, K. Ruotsalainen, R. Decker, A. Pietzsch   +4 more
wiley   +1 more source

Mechanistic investigations of polyaza[7]helicene in photoredox and energy transfer catalysis

Beilstein Journal of Organic Chemistry
Organic photocatalysts frequently possess dual singlet and triplet photoreactivity and a thorough photochemical characterization is essential for efficient light-driven applications.
Johannes Rocker, Till J. B. Zähringer, Matthias Schmitz, Till Opatz, Christoph Kerzig   +4 more
doaj   +1 more source

Learning Strategies from Nature's Blueprint to Cyclic Carbonate Synthesis

ChemSusChem, Volume 18, Issue 6, March 15, 2025.
The development of sustainable synthetic methods for cyclic carbonates draws inspiration from nature, focusing on eco‐friendly processes and renewable resources like CO2 and biomass. This review explore various CO2 activation mechanisms, green chemistry principles, and green catalysts.
Erika Saccullo, Vincenzo Patamia, Chiara Zagni, Antonio Rescifina, Giuseppe Floresta   +4 more
wiley   +1 more source

A Crystalline Ylide‐Stabilized Stibenium Cation

European Journal of Inorganic Chemistry, EarlyView.
The isolation of a stibenium cation stabilized by two thiophosphinoyl‐tethered ylide groups is reported. The cation is accessible via salt metathesis of the metalated ylide with SbCl3 and features CSb single bonds, with lone pairs remaining localized at the ylidic carbon atoms.
Daniel Knyszek, Margarita Shishkova, Leif Kelling, Henning Steinert, Viktoria H. Gessner   +4 more
wiley   +1 more source

From [NHC─H]• to Persistent σ‐Complex Radicals: Photoinduced Radical Chemistry of Imidazolium Salts

Angewandte Chemie, Volume 138, Issue 24, 8 June 2026.
Visible‐light excitation of electron donor–acceptor (EDA) complexes between imidazolium salts and triarylamines enables controlled single‐electron transfer (SET) and reveals a family of carbene‐centered σ‐complex radical cations. Cryogenic electron paramagnetic resonance (EPR) captures the elusive [NHC─H]• intermediate and its thermal evolution into ...
Filipp M. Kolomeychuk, Lars J. C. van der Zee, Simon Mathew, Bas de Bruin, J. Chris Slootweg   +4 more
wiley   +2 more sources

Development of Guanidine-Bisurea Bifunctional Organocatalysts with a Chiral Pyrrolidine Moiety and Application to α-Hydroxylation of Tetralone-Derived β-Keto Esters

Molecules, 2015
Novel guanidine-bisurea bifunctional organocatalysts 5 bearing a chiral pyrrolidine moiety on guanidine were designed with the guidance of DFT calculations.
Minami Odagi, Kan Takayama, Makoto Sato, Masahiro Yamanaka, Kazuo Nagasawa   +4 more
doaj   +1 more source

Mechanistic and Reactivity Insights into Diboron‐Mediated NN and NN Bond Scission

European Journal of Organic Chemistry, EarlyView.
This review highlights the emerging ability of diboron reagents to cleave both π‐bonded (N=N) and σ‐bonded (N—N) nitrogen–nitrogen linkages, integrating mechanistic understanding with recent synthetic applications. Diboron reagents have emerged as versatile reducing agents capable of transforming a broad range of functional groups through pathways like
Raúl Valderrama‐Callejón, Inés Alonso, M. Belén Cid   +2 more
wiley   +1 more source

Isotellurourea‐Catalyzed Enantioselective (4+2)‐Heterocycloadditions of But‐2‐ynoates and Michael Acceptors

European Journal of Organic Chemistry, EarlyView.
Isotelluroureas allow for the use of alkynoates for asymmetric (4+2)‐heterocycloadditions with different Michael acceptors. Alk‐2‐ynoates are readily available starting materials which, in principle, can be utilized for cycloadditions in analogy to structurally similar allenoates.
Anna Scheucher, Mario Waser
wiley   +1 more source

Synthesis of Benzopyran Atropisomers via Electrophilic Halogenation

European Journal of Organic Chemistry, EarlyView.
We report a halogenation‐based method for the synthesis of axially chiral benzopyrans, tolerating diverse substituents and halogens (Br, Cl, and I). A double bromination gives bisbenzopyrans with two stereogenic axes. Preliminary enantioselective conditions yield benzopyran atropisomer with up to 56% ee.
Alix Bourhis, Expédite Yen‐Pon, Jean Rodriguez, Damien Bonne   +3 more
wiley   +1 more source