Results 131 to 140 of about 13,012 (246)

Production of constrained L-cyclo-tetrapeptides by epimerization-resistant direct aminolysis

Nature Communications
The synthesis of constrained 12-membered rings is notably difficult. The main challenges result from constraints during the linear peptide cyclization. Attempts to overcome constraints through excessive activation frequently cause peptidyl epimerization,
Huan Chen, Yuchen Zhang, Yuming Wen, Xinhao Fan, Nicholas Sciolino, Yanyun Lin, Leonard Breindel, Yuanwei Dai, Alexander Shekhtman, Xiao-Song Xue, Qiang Zhang   +10 more
doaj   +1 more source

Flipping the Card With Enantiodivergent Organocatalysis

Chemistry – A European Journal, Volume 32, Issue 29, 7 August 2026.
This minireview elaborates on recent organocatalytic strategies for achieving enantiodivergence—the ability to access both product enantiomers using a single chiral catalyst. It highlights how achiral stimuli, such as solvent polarity and chemical additives, along with minimal catalyst modifications, trigger stereochemical inversions in reactions ...
Debora Iapadre, Alessio Carioscia, Alessandro Brusa, Armando Carlone   +3 more
wiley   +1 more source

Epimerization of Borneol. I-III. III. Homogeneous Epimerization. Epimerization with Sodium Alkoxide.

Nippon kagaku zassi, 1958
Tsuneichi Takeshita, Masayoshi Kitajima
openaire   +2 more sources

Synthesis of Peptides by Reactive Extrusion. Application to the Continuous and Solventless Preparation of Aspartame.

ChemistryEurope
The solventless synthesis of peptides from unactivated amino acids was optimized in a twin‐screw extruder (TSE). The general method enabled the preparation of dipeptides and tripeptides with no epimerization.
Dr. Tharwat Mohy El‐Dine, Matthieu Lavayssiere, Dr. Hélène Adihou, Prof. Gilles Subra, Dr. Thomas‐Xavier Métro, Dr. Olivier Ludemann‐Hombourger, Dr. Frédéric Lamaty   +6 more
doaj   +1 more source

Chemoenzymatic Synthesis of Chiral Piperidines Using the Immobilized Transaminase ATA‐117 in Continuous Flow Reactors

Advanced Synthesis &Catalysis, Volume 368, Issue 15, 1 August 2026.
A robust continuous flow chemoenzymatic process was developed for the stereoselective synthesis of cis‐(2R,6R)‐2,6‐disubstituted piperidines, including the natural alkaloid (–)‐pinidinone. The asymmetric transamination of α,β‐unsaturated ketones was catalyzed by immobilized ATA‐117, followed by spontaneous aza‐Michael cyclization, providing the desired
Sara Vicinanza, Ilaria Magrini Alunno, Stefania Patti, Morena Pirotta, Francesca Annunziata, Raffaella Gandolfi, Paola Conti, Chiara Borsari, Ivan Bassanini, Erica Elisa Ferrandi, Daniela Monti, Lucia Tamborini   +11 more
wiley   +1 more source

Epimeric [PDF]

, 2020
openaire   +1 more source

Atroposelective Access to π‐Conjugated 1,2‐Azaborepines Enabled by Palladium‐Catalyzed Cyclization of N‐Heterobiaryls with Alkynylboronates

Advanced Science, Volume 13, Issue 45, 13 August 2026.
We report a palladium‐catalyzed atroposelective cyclization of N‐heterobiaryl triflates with alkynyl boronates to access seven‐membered 1,2‐BN‐bridged biaryls with high yields and excellent enantioselectivity via a cascade DyKAT, cis‐carbopalladation, and 1,2‐migration, which expands the toolbox for axially chiral π‐conjugated boron compounds and opens
Fengya He, Zhen Wang, Haoyu Guo, Shuguang Chen, Xu Zhang, Yongjia Shang, Hui Wang   +6 more
wiley   +1 more source

Electrochemical Chlorination of Levulinic Acid

Electrochemical Science Advances, Volume 6, Issue 4, August 2026.
ABSTRACT Levulinic acid is a cellulose‐derived, sustainable feedstock with significant potential for use in renewable, carbon‐based polymer and chemical synthesis. In this work, electrochemical chlorination has been investigated as a method for preparing chlorinated levulinic acid derivatives, which can serve as valuable intermediates for the synthesis
Ananda S. Amarasekara, M. A. G. K. Manchanayake   +1 more
wiley   +1 more source

Peptides on Tap: Automated Flow Synthesis With Standard HPLC

Helvetica Chimica Acta, Volume 109, Issue 8, August 2026.
A standard analytical HPLC system is repurposed into a fully automated, flow‐based peptide synthesis platform. By leveraging the autosampler for automated reagent injections into a resin‐packed guard column, this highly accessible method enables rapid, temperature‐controlled coupling with real‐time UV monitoring, producing high‐purity peptides and ...
Patrick Romanens, Sofia Barluenga, Millicent Dockerill, Guixian Zhao, Francesco Russo, Nicolas Winssinger   +5 more
wiley   +1 more source

Keratan Sulfate: An Electroconductive Glycosaminoglycan at the Interface of Sensory Perception and Neural Signaling

Journal of Neuroscience Research, Volume 104, Issue 8, August 2026.
Laboratory studies show KS has electroconductive properties with the ability to trap and transport protons in neurotransductive processes (Grotthuss proton shuttling). This maintains electrochemical gradients and fluxes at the neuronal cell surface in neural activation. Such processes are central to neuronal cell signaling and communication.
James Melrose
wiley   +1 more source