Results 91 to 100 of about 37,689 (286)

Iridium-Catalyzed Asymmetric Ring-Opening of Oxabenzonorbornadienes with N-Substituted Piperazine Nucleophiles

Molecules, 2015
Iridium-catalyzed asymmetric ring-opening of oxabenzonorbornadienes with N-substituted piperazines was described. The reaction afforded the corresponding ring-opening products in high yields and moderate enantioselectivities in the presence of 2.5 mol % [
Wen Yang, Renshi Luo, Dingqiao Yang
doaj   +1 more source

A cost‐effective DNA extraction protocol for long‐read sequencing in non‐model plants

Applications in Plant Sciences, EarlyView.
Abstract Premise Third‐generation sequencing has revolutionized genomics, enabling in‐depth analysis of genome sequence, structure, and epigenetic features. Yet, extracting high‐quality DNA for long‐read sequencing remains a bottleneck—particularly in non‐model plants, such as mature trees growing in natural environments, which often contain abundant ...
Sofia Gaischuk, Cintia F. Marchetti, Ezequiel Petrillo, Fernando A. Rabanal, Detlef Weigel, Nicolás Bellora, M. Verónica Arana   +6 more
wiley   +1 more source

Sorption and permeation of aqueous alkyl piperazines through hydrophilic and organophilic membranes: a transport analysis

, 1998
A detailed analysis of separation of N-methyl piperazine (NMP), N-ethyl pipera-zine (NEP), and water was undertaken by the pervaporation technique.
Pangarkar, V. G., Dagaonkar, M. V., Joshi, J. B., Sawant, S. B.   +3 more
core   +1 more source

Simplified Procedure for General Synthesis of Monosubstituted Piperazines—From a Batch Reaction Vessel to a Flow (Microwave) Reactor

Molecules, 2020
We reported a novel simplified synthetic procedure for the preparation of monosubstituted piperazine derivatives which can now be easily prepared in a one-pot-one-step way from a protonated piperazine with no need of introduction of a protecting group ...
Dana Němečková, Eva Havránková, Jan Šimbera, Richard Ševčík, Pavel Pazdera   +4 more
doaj   +1 more source

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

Mechanochemical Amidation Mediated by 1,1’‐Oxalyldiimidazole for the Synthesis of Agrochemicals

Chemistry – A European Journal, EarlyView.
Mechanochemical amidation using 1,1'‐oxalyldiimidazole (ODI) overcomes limitations of 1,1’‐carbonyl diimidazole (CDI) as coupling agent by enabling the efficient mechanochemical synthesis of three marketed agrochemicals from deactivated carboxylic acids.
Andrea Casagrande, Rubén Solorzano‐Rodriguez, Maria Carta, Francesco Delogu, Joris Vezzani, Allan Niidu, Evelina Colacino   +6 more
wiley   +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   +5 more
core   +1 more source

Synthesis of N‑Pyrrolyl(furanyl)-Substituted Piperazines, 1,4-Dizepanes, and 1,4-Diazocanes

, 2019
The synthetic potential of 5-bromo-1,1,1-trifluoro-4-methoxypent-3-en-2-one toward the catalyst-free synthesis of N-pyrrolyl­(furanyl)-piperazines, 1,4-diazepanes, and 1,4-diazocanes through a telescoped protocol is reported. This three-component one-pot
Lucimara L. Zachow, Clarissa P. Frizzo (1457206), Marcos A. P. Martins, Nilo Zanatta, Helio G. Bonacorso (1457209), Marcos A. P. Martins (1457212), Mateus Mittersteiner (6899375), Clarissa P. Frizzo, Mateus Mittersteiner, Lucimara L. Zachow (3341348), Valquiria P. Andrade, Valquiria P. Andrade (6899378), Helio G. Bonacorso, Nilo Zanatta (1457224)   +13 more
core   +3 more sources

Performance comparison of pressure swing adsorption and amine‐based absorption for synthesis gas purification

The Canadian Journal of Chemical Engineering, EarlyView.
Comparison of PSA and amine‐based absorption for syngas purification shows that PSA offers lower energy intensity, global warming potential, and minimum selling price, making it a more sustainable option. However, absorption achieves higher syngas purity. A GREENSCOPE‐based multi‐criteria assessment guides optimal process selection.
Magno Fonseca Santos, Antonio Esio Bresciani, Rita Maria Brito Alves   +2 more
wiley   +1 more source