Results 71 to 80 of about 12,340 (258)

Cationic Sulfonium‐Based Tripodal Ligand and Its Rh(I) Complexes

Chemistry – A European Journal, EarlyView.
We report a cationic EP3‐type tripodal ligand based on an aromatic sulfonium cation (E = S+) along with a series of its Rh(I) complexes. Structural, spectroscopic, electrochemical, and computational analyses of these complexes compared to isostructural analogs (E = Si− or P) reveal pronounced electron density depletion at Rh in the sulfonium congener ...
Nitsan Barel, Shrouq Mujahed, Kamal Uddin Ansari, Katarzyna Młodzikowska‐Pieńko, Renana Gershoni‐Poranne, Yuri Tulchinsky   +5 more
wiley   +1 more source

Lignin modification by epoxidation

BioResources, 2008
The chemical modification of lignin through hydroxymethylation and epoxidation is a way to develop new application fields and improvement of lignin performances. In this paper the influence of reaction conditions was studied using different samples of unmodified and modified lignins from annual plants (Wheat straw and Sarkanda grass).
Theodor Malutan, Raluca Nicu, Valentin I. Popa   +2 more
openaire   +2 more sources

Harnessing Random Polymers as Chemoselective Catalysts With Structural Adaptability: Epoxidation of Olefinic Quaternary Ammonium Salts via Charge Recognition

Chemistry – A European Journal, EarlyView.
The development of chemoselective catalysts that operate across structurally diverse substrates remains a long‐standing challenge. Here, we demonstrate that a random heteropolymer bearing carboxylic acid and urea residues functions as a general epoxidation catalyst for olefinic quaternary ammonium salts.
Yusei Fujii, Kiyosei Takasu, Yusuke Kuroda   +2 more
wiley   +1 more source

Strain Release of 1‐Azabicyclo[1.1.0]butanes as a Gateway to Highly Functionalized Azetidines: New Strategies and Structural Motifs

Chemistry – A European Journal, EarlyView.
Over the past decade, the interest in azetidines has continuously risen, by virtue of their highly appealing pharmaceutical properties. Monocyclic, spirocyclic, and bridged azetidines can be accessed by leveraging 1‐azabicyclo[1.1.0]butanes as precursors.
Yuri Gelato, Philipp Natho, Marco Colella, Renzo Luisi   +3 more
wiley   +1 more source

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

Beilstein Journal of Organic Chemistry, 2018
The alternating copolymerization of epoxides with cyclic anhydrides (CAs) is a highly diverse synthetic method for polyesters as the polymers’ architectures and properties can be easily controlled depending on the combination of two monomers.
Yo Hiranoi, Koji Nakano
doaj   +1 more source

Covalent Insertion of a Mn(Salen) Type Complex in Cross‐Linked Protein Crystals: Design of an Enantioselective Artificial Epoxidase

Chemistry – A European Journal, EarlyView.
An Artificial metalloenzyme was designed by a Michael addition between a MnSalen complex and a cysteine residue within NikA crystals. The heterogeneous catalyst was found capable of an enantioselective and stereospecific epoxidation of cis‐β‐methylstyrene in cristallo.
Manel Boukhallat, Ismail Benhamed, Jade Arnone, Stann Van Baaren, Clara Rinaldi, Patrice Catty, Caroline Marchi‐Delapierre, Christine Cavazza, Stéphane Ménage   +8 more
wiley   +1 more source

Solid-phase enrichment and analysis of electrophilic natural products

Beilstein Journal of Organic Chemistry, 2017
In search for new natural products, which may lead to the development of new drugs for all kind of applications, novel methods are needed. Here we describe the identification of electrophilic natural products in crude extracts via their reactivity ...
Frank Wesche, Yue He, Helge B. Bode
doaj   +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

Synthesis and Characterization of γ-Fe2O3@HAp@β-CD Core-Shell Nanoparticles as a Novel Magnetic Nanoreactor and Its Application in the One-Pot Preparation of β-azido Alcohols, β-nitro Alcohols, and β-cyanohydrins [PDF]

Iranian Journal of Chemistry & Chemical Engineering, 2019
In this study, β-cyclodextrin(β-CD) supported, hydroxyapatite encapsulated γ-Fe2O3 (γ-Fe2O3@HAp@β-CD) was successfully prepared and evaluated as a solid-liquid phase transfer catalyst and also a molecular host system and nanoreactor for the nucleophilic ...
Sara Khosravinia, Ali Reza Kiasat, Seyyed Jafar Saghanezhad   +2 more
doaj  

Switching the reaction pathways of electrochemically generated β-haloalkoxysulfonium ions – synthesis of halohydrins and epoxides

Beilstein Journal of Organic Chemistry, 2015
β-Haloalkoxysulfonium ions generated by the reaction of electrogenerated Br+ and I+ ions stabilized by dimethyl sulfoxide (DMSO) reacted with sodium hydroxide and sodium methoxide to give the corresponding halohydrins and epoxides, respectively, whereas ...
Akihiro Shimizu, Ryutaro Hayashi, Yosuke Ashikari, Toshiki Nokami, Jun-ichi Yoshida   +4 more
doaj   +1 more source