Results 21 to 30 of about 4,901 (180)

Chitosan‐Graft‐Gelatin Hydrogel Containing Bromothymol Blue as a Food Spoilage Indicator for Intelligent Food Packaging

Advanced Materials Interfaces, EarlyView.
A chitosan‐graft‐gelatin hydrogel, incorporating a pH‐responsive dye, bromothymol blue, as a colorimetric freshness indicator is introduced to monitor the spoilage of chicken breasts. The hydrogel indicates microbial activity, and the production of carbon dioxide due to deteriorating food freshness via a change in pH, and serves as a smart and visual ...
Bahareh Farasati Far, Mehdi Jahanbakhshi, Leila Jameie, Asefeh Shojaei, Kimia Zarei, Parsa Taromi, Shima Jafarzadeh, Yavuz Nuri Ertas   +7 more
wiley   +1 more source

Photoinduced Catalytic Alkylation of Active Methine Compounds with Nonactivated Alkenes Using Yttrium Triflate as a Lewis Acid Catalyst

Advanced Synthesis &Catalysis, EarlyView.
Abstract Photoinduced catalytic alkylation reactions of active methine compounds with nonactivated alkenes have been developed using an organophotocatalyst, a metal Lewis acid, an arylthiol, and an amine base catalyst system. The alkylation reactions proceeded smoothly under ambient conditions with blue light irradiation, affording the desired products
Yasuhiro Yamashita, Rentaro Enokijima, Yoshihiro Ogasawara, Tomoya Hisada, Shū Kobayashi   +4 more
wiley   +1 more source

Double‐Sided Control of Product Type Preference in the Visible‐Light Initiated Reaction of 1,3‐Dicarbonyl Compounds with Alkenes

Advanced Synthesis &Catalysis, EarlyView.
Abstract The demonstrated light‐initiated addition of radicals formed on an active methylene group to styrene derivatives exhibits a product selectivity influenced by the presence of a protic solvent. Under protic conditions, the predominant products are branched compounds with the alkene moiety attached to the methylene group.
Małgorzata Pałyga, Jan Rzepiela, Sebastian Baś   +2 more
wiley   +1 more source

Regio‐ and Enantioconvergent Hydroallylation of Acrylates Enabled by γ‐Silyl‐Substituted Allyl Acetates

Angewandte Chemie International Edition, Accepted Article.
Transition‐metal‐catalyzed asymmetric allylic substitution provides an efficient route to chiral organic molecules featuring an allyl moiety, key intermediates in the synthesis of biologically active compounds. However, the use of unsymmetrical 1,3‐disubstituted allyl electrophiles has been severely constrained by the challenges of achieving both regio‐
Hirotsugu Suzuki, Ryoichi Nishikawa, Yuki Sato, Kaisei Sekino, Takanori Matsuda   +4 more
wiley   +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

Palladium‐Catalyzed [3+2] Cycloadditions of Alkylidenecyclopropanes to Imines: A Direct Approach to Pyrrolidine Scaffolds

ChemistryEurope, EarlyView.
Pd‐catalyzed annulations of ACPs with different C=N partners in both inter‐ and intramolecular ways are described. The methods provide access to pyrrolidines and pyrrolidine‐fused polycyclic systems, featuring β‐exo‐methylene moieties. Preliminary enantioselective variant has been shown by using a chiral phosphoramidite ligand and DFT studies shed ...
Ricardo Rodiño, Felipe Verdugo, José L. Mascareñas, Fernando López   +3 more
wiley   +1 more source

Chemoselective or Regioselective?

ChemistryEurope, EarlyView.
The current definitions of chemoselectivity and regioselectivity lack sufficient clarity and allow for the ambiguous labeling of reported reaction selectivities in some instances. This article proposes a rationale and simplified definitions of these terms that will facilitate an unambiguous description of the observed reaction selectivity.
Andrej Kolarovič, Pavol Jakubec
wiley   +1 more source

Biomimetic Growth of Calcium Oxalate Hydrates: Shape Development and Structures in Agar Gel Matrices

Chemistry – A European Journal, EarlyView.
The biomimetic growth of calcium oxalate hydrates is conducted using a double diffusion technique in agar gel. The results reveal the shape development of calcium oxalate monohydrate (COM) and dihydrate (COD), resembling biominerals of kidney stones. The pH variations influence phase selection, with COM forming at lower pH and COD at higher pH.
Annu Thomas, Paul Simon, Wilder Carrillo‐Cabrera, Elena Sturm   +3 more
wiley   +1 more source

Carbazole Framework as Functional Scaffold for the Design of Synthetic Receptors

Chemistry – A European Journal, EarlyView.
Carbazole‐based receptors play a crucial role in supramolecular chemistry, due to their unique geometry, photophysical properties, strong hydrogen bonding features, and versatility. This review examines prominent examples, focusing on how structural modifications shape binding affinity and selectivity for various guests, showcasing the potential of ...
Alessio Carioscia, Debora Iapadre, Elena Incerto, Jonathan Di Pietro, Luisa Giansanti, Fabio Pesciaioli, Armando Carlone   +6 more
wiley   +1 more source

Visible‐Light Photocatalysis for Sustainable Chromene Synthesis and Functionalization

Chemistry – A European Journal, EarlyView.
Visible‐light photocatalysis provides sustainable and versatile methods for the synthesis and functionalization of chromene derivatives. This review compiles cutting‐edge methodologies, highlighting transformations such as multicomponent reactions, cross‐dehydrogenative coupling reactions, diverse cascade processes, and Giese‐type additions.
Paula Pérez‐Ramos, Georgia Biniari, Raquel G. Soengas, Humberto Rodríguez‐Solla, Carmen Simal   +4 more
wiley   +1 more source