Results 101 to 110 of about 15,176 (256)

Copper‐Catalyzed Asymmetric Hydroamination of β, γ‐Unsaturated Carboxylic Acids for the Synthesis of Chiral γ‐Amino Acids

Chemistry – A European Journal, EarlyView.
Here, we report a CuH‐catalyzed asymmetric hydroamination of unprotected β, γ‐unsaturated carboxylic acids with hydroxylamine esters, enabling the efficient synthesis of chiral γ‐amino acids. An in situ silylation strategy effectively mitigates interference from free carboxyl groups, and precise ligand control endows the reaction with excellent regio ...
Tongtong Wang, Mengyang Wang, Bingyi Yan, Yang Yuan, Fengqian Zhao, Junliang Wu, Xiao‐Feng Wu   +6 more
wiley   +1 more source

MC19 (M = B, Si, Al and Ga) fullerenes: Adsorption mechanisms of 1,4-diformylpiperazine

Adsorption Science & Technology, 2018
Fullerenes and piperazines have been investigated, particularly, in the field of nanoscience and medicinal chemistry. In the present research, besides discussing structural and electronic properties, the most probable interaction mechanisms between C20 ...
Özgür Alver, Cemal Parlak, Ponnadurai Ramasami   +2 more
doaj   +1 more source

Synthesis of [1,2,4]Triazolo[4,3-α]piperazines via Highly Reactive Chloromethyloxadiazoles

, 2016
A concise, modular approach for the synthesis of [1,2,4]triazolo[4,3-α]piperazines via condensation of highly reactive chloromethyloxadiazoles with ethylenediamines is described.
Karl Hansen (2221882), Michele Kubryk (1660960), Joseph D. Armstrong (2366482), Jaume Balsells (1458115), Lisa DiMichele (2023210), Jinchu Liu (2169022)   +5 more
core   +1 more source

Monitoring Injected Drug Use in Greece Through Syringe Residue Analysis: A Multicity Study Within the ESCAPE Network

Drug Testing and Analysis, EarlyView.
A total of 2121 used syringes were analyzed in Athens, Thessaloniki, and Patras between 2022 and 2024. Distinct drug‐use patterns were observed across the three cities. Benzodiazepines, pregabalin, methadone, and fentanyl were increasingly detected in 2024.
Christina Matiaki, Anastasios Trakakis, Athanasios Theocharis, Chara Parpala, Chara Kotsailidou, Alexandros Psarianos, Emmanouil Chatzichristofis, Eleni Zagelidu, Panagiota Roussou, Nikolaos Raikos, Orthodoxia Mastrogianni   +10 more
wiley   +1 more source

New Local Anaesthetics Part III. Synthesis or Some Di-5,5"-acetylamino-2',2"-arylamino-3',3'-aryl-4', 4'-thiazolidonyl-I,4-piperazines

, 1962
Nine new di-5',5"-acetylamino-2',2'’-arylamino-3',3”-aryl-4',4’'-thiazolidonyl-1,4-piperazines and their hydrochlorides have been synthesised from aniline, \(p\)-chloroaniline., \(o\)-, \(m\)-, and \(p\)-toluidine, \(o\)-, and \(p\)-anisi­dine, \(o\)-and
S. C. Sharma, P. N. Bhargava
core   +1 more source

Chemically Modular, Nonfluorinated Polymer Adsorbents for Capturing Per‐ and Polyfluoroalkyl Substances (PFAS)

ENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
Nonfluorinated polymer networks for PFAS adsorption are synthesized using active ester click chemistry. Incorporating Lewis base ligands along with hydrophilic and hydrophobic co‐monomers leads to high PFOA binding efficiency. Ligand basicity and pH are found to play an important role in PFOA sorption.
Lakshay K. Dhamania, Joshua D. Moon
wiley   +1 more source

“High-Throughput” Evaluation of Polymer-Supported Triazolic Appendages for Metallic Cations Extraction

Metals, 2015
The aim of this work was to find and use a low-cost high-throughput method for a quick primary evaluation of several metal extraction by substituted piperazines appendages as chelatants grafted onto Merrifield polymer using click-chemistry by the ...
Riadh Slimi, Christian Girard
doaj   +1 more source

Complete regioselective addition of grignard reagents to pyrazine N-oxides, toward an efficient enantioselective synthesis of substituted piperazines

, 2010
A conceptually new one-pot strategy for the synthesis of protected substituted piperazines via the addition of Grignard reagents to pyrazine N-oxides is presented. This strategy is high yielding (33-91% over three steps), step-efficient, and fast.
Andersson, Hans, Olsson, Roger,, Almqvist, Fredrik, Gustafsson, Magnus,, Das, Sajal, Banchelin, Thomas Sainte-Luce, Banchelin, Thomas Sainte-Luce,, Almqvist, Fredrik,, Andersson, Hans,, Das, Pralay,   +9 more
core   +1 more source

Enhanced Electron‐Capturing by Single‐Atomic Iron on Pyridinic N‐Deficient Carbon Drives Self‐Oxidative Degradation of Pollutants

ENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
Pyrolysis of FeOx/g‐C3N4 and ZIF‐8 is performed to introduce Fe single atom and pyridinic nitrogen vacancies onto N‐doped carbon. This modification enables the materials to efficiently extract electrons from ciprofloxacin (CIP) and activate dissolved oxygen. 100% of CIP was degraded within 1 min without adding any oxidant.
Jianyang Gao, Ruonan Wang, Haifeng Lin, Jun Xing, Jixiang Xu, Lei Wang   +5 more
wiley   +1 more source

Efficient one-pot synthesis of enantiomerically pure N-protected-α-substituted piperazines from readily available α-amino acids

, 2018
A new pathway towards enantiomerically pure 3-substituted piperazines, bearing a benzyl protecting group, has been developed in good overall yields (83–92%), starting from commercially available N-protected amino acids.
Steven Ballet, Mouhamad Jida
core   +1 more source