Results 31 to 40 of about 9,903,999 (366)

Solvent Effects in the Regioselective N-Functionalization of Tautomerizable Heterocycles Catalyzed by Methyl Trifluoromethanesulfonate: A Density Functional Theory Study with Implicit Solvent Model

Computation, 2022
Methyl trifluoromethanesulfonate was found to catalyze the reaction of the nucleophilic substitution of the hydroxyl group of alcohols by N-heterocycles followed by X- to N- alkyl group migration (X = O, S) to obtain N-functionalized benzoxazolone ...
Nelson H. Morgon, Srijit Biswas, Surajit Duari, Aguinaldo R. de Souza   +3 more
doaj   +1 more source

Synthesis and Spectroscopic Characterization of Two Tetrasubstituted Cationic Porphyrin Derivatives

Molecules, 2011
An imidazolium tetrasubstituted cationic porphyrin derivative (the free base and its Zn(II) complex) with five-membered heterocyclic groups in the meso-positions were synthesized using microwave irradiation, and the compounds obtained characterized by 1H-
Newton M. Barbosa Neto, José A.S. Cavaleiro, Antonio E.H. Machado, Rodrigo De Paula, Diesley M.S. Araújo, Hércules S. Miglio, Leonardo T. Ueno, Weverson R. Gomes   +7 more
doaj   +1 more source

Biodiesel production from jatropha seeds: Solvent extraction and in situ transesterification in a single step [PDF]

, 2013
The objective of this study was to investigate solvent extraction and in situ transesterification in a single step to allow direct production of biodiesel from jatropha seeds.
Evon, Philippe, Amalia Kartika, Ika, Ariono, Danu, Yani, Muhammad, Rigal, Luc   +4 more
core   +1 more source

Benzoxazole Iminocoumarins as Multifunctional Heterocycles with Optical pH-Sensing and Biological Properties: Experimental, Spectroscopic and Computational Analysis

Chemosensors
A novel series of benzoxazole-derived iminocoumarins was synthesized via a Knoevenagel condensation and fully characterized using NMR, UV–Vis spectroscopy, and computational methods. Their photophysical properties were systematically examined in solvents
Marina Galić, Ana Čikoš, Leentje Persoons, Dirk Daelemans, Karolina Vrandečić, Maja Karnaš, Marijana Hranjec, Robert Vianello   +7 more
doaj   +1 more source

Solvent Effect on the Photolysis of Riboflavin [PDF]

AAPS PharmSciTech, 2015
The kinetics of photolysis of riboflavin (RF) in water (pH 7.0) and in organic solvents (acetonitrile, methanol, ethanol, 1-propanol, 1-butanol, ethyl acetate) has been studied using a multicomponent spectrometric method for the assay of RF and its major photoproducts, formylmethylflavin and lumichrome.
Iqbal, Ahmad, Zubair, Anwar, Sofia, Ahmed, Muhammad Ali, Sheraz, Raheela, Bano, Ambreen, Hafeez   +5 more
openaire   +2 more sources

Solvent-Mediated Rate Deceleration of Diels–Alder Reactions for Enhanced Selectivity: Quantum Mechanical Insights

Chemistry
Solvents can have a tremendous influence on the rate and selectivity of chemical reactions, but their effects are not always well accounted for. In the present work, density functional theory computations are used to investigate the influence of solvent ...
Umatur Rehman, Asim Mansha, Felix Plasser   +2 more
doaj   +1 more source

Theoretical Studies on the Electronic Structure Parameters and Reactive Activity of Neu5Gc and Neu5Ac under Food Processing Solvent Environment

Molecules, 2019
The animal product hazard factor N-glycolylneuraminic (Neu5Gc) and brain nutrient substance N-acetylneuraminic acid (Neu5Ac) were studied at the M062X/6-311 + G(d,p) geometry optimization level.
Rui Chang, Bowen Yang, Qiu-Jin Zhu
doaj   +1 more source

Solid Pseudopapillary Neoplasm of the Pancreas in Children and Adolescents: Expert Recommendations

Pediatric Blood &Cancer, EarlyView.
ABSTRACT Solid pseudopapillary neoplasm of the pancreas (SPN) is a rare low‐grade malignant exocrine pancreatic tumor, mostly discovered during the second decade of life in females, with a very good prognosis, provided microscopically complete surgical excision is achieved.
Sabine Irtan, Michael Abele, Calogero Virgone, Michaela Kuhlen, Ricardo Lopez‐Almarez, Tal Ben‐Ami, Ewa Bien, Maja Cesen, Malgorzata A. Krawczyk, Andrea Ferrari, Gianni Bisogno, Yves Reguerre, Dominik T. Schneider, Louise Galmiche, Jorg Fuchs, Sarah Braungart, Bilgehan Yalcin, Ines B. Brecht, Daniel Orbach   +18 more
wiley   +1 more source

Activation of Electrophile/Nucleophile Pair by a Nucleophilic and Electrophilic Solvation in a SNAr Reaction

Frontiers in Chemistry, 2018
Nucleophilic aromatic substitution reactions of 4-chloroquinazoline toward aniline and hydrazine were used as a model system to experimentally show that a substrate bearing heteroatoms on the aromatic ring as substituent is able to establish ...
Bruno Sánchez, Cristian Calderón, Ricardo A. Tapia, Renato Contreras, Paola R. Campodónico   +4 more
doaj   +1 more source

Ovarian Sex Cord Stromal Tumors in Children and Adolescents—The European Standard Clinical Practice Recommendations

Pediatric Blood &Cancer, EarlyView.
ABSTRACT As part of the European Cooperative Study Group for Paediatric Rare Tumours initiative, we developed standard clinical practice guidelines for ovarian sex cord stromal tumors, based on comprehensive national and international cohort analyses, literature review, and a final expert consensus conference.
Dominik T. Schneider, Kris‐Ann Schultz, Nora Schnitzler, Michael Abele, Tal Ben‐Ami, Ewa Bien, Gianni Bisogno, Ines B. Brecht, Maja Cesen, Andrea Ferrari, Michaela Kuhlen, Malgorzata A. Krawczyk, Ricardo Lopez‐Almaraz, Yves Reguerre, Calogero Virgone, Daniel Orbach   +15 more
wiley   +1 more source