Results 51 to 60 of about 9,300 (167)

Asymmetric aerobic oxidative NHC-catalysed synthesis of dihydropyranones utilising a system of electron transfer mediators [PDF]

, 2016
In the context of green chemistry, the replacement of high molecular weight stoichiometric oxidants with O2 is most desirable but difficult. Here, we report the asymmetric aerobic oxidative synthesis of dihydropyranones.
Axelsson, Anton, Hammarvid, Emmelie, Sundén, Henrik, Ta, Linda   +3 more
core   +1 more source

Tautomerism of 4-Pyridones [PDF]

Bulletin of the Chemical Society of Japan, 1977
Abstract The tautomeric constants, Kt, of several 4-pyridones were determined by measurement of pKa values. For 2-substituted 5-methoxy-4-pyridones, the Kt values were correlated to the substituent constants σ, the equation logkt=2.98+2.93σm−6.18σo being obtained.
Hiromichi Besso, Kimiaki Imafuku, Hisashi Matsumura   +2 more
openaire   +1 more source

Nicotinamide (Vitamin B3) Deficiency in Follicular Fluid of Patients With Ovarian Ageing

Journal of Cellular and Molecular Medicine, Volume 30, Issue 6, March 2026.
ABSTRACT Nicotinamide is an essential precursor of NAD involved in energy metabolism. A decline in NAD levels across tissues during ageing is well‐documented, and NAD metabolism has been implicated in ovarian ageing. We investigated the relationship between ovarian ageing and the levels of nicotinamide (NAM) and its metabolite 1‐methylnicotinamide (MNA)
Cinzia Bocca, Magalie Boguenet, Lisa Boucret, Pierre‐Emmanuel Bouet, Pascal Reynier, Pascale May‐Panloup   +5 more
wiley   +1 more source

Controle de plantas daninhas na cultura do milho utilizando leucena (Leucaena leucocephala (Lam.) de wit). [PDF]

, 2018
Avaliou-se o efeito da parte aérea da leucena, em condiçoes de casa de vegetação e campo, sobre o desenvolvimento de plantas daninhas, fitotoxicidade para o milho e acréscimo de nitrogênio para a cultura. Em casa de vegetação (vasos) foram avaliadas 25 t
PEREIRA FILHO, I. A., PIRES, N. de M., PRATES, H. T.   +2 more
core   +1 more source

Timing of NAD Deficiency During Organogenesis Dictates Defect Type and Penetrance

The FASEB Journal, Volume 40, Issue 3, 15 February 2026.
Pregnant mice on a vitamin B3‐free and tryptophan‐limited diet have embryos with Congenital NAD Deficiency Disorder, characterized by malformations and/or death. We longitudinally tracked the maternal NAD metabolome, embryo growth, and malformation occurrence. Mice with lower NAD Salvage Pathway metabolite levels and minimal levels of derived excretion
Kayleigh Bozon, Hartmut Cuny, Nana Sunn, Ella M. M. A. Martin, Delicia Z. Sheng, Gavin Chapman, Sally L. Dunwoodie   +6 more
wiley   +1 more source

Stoichiometric and catalytic C-C and C-H bond formation with B(C6F5)3 via cationic intermediates [PDF]

, 2017
This work showcases a new catalytic cyclization reaction using a highly Lewis acidic borane with concomitant C−H or C−C bond formation. The activation of alkyne‐containing substrates with B(C6F5)3 enabled the first catalytic intramolecular cyclizations ...
Al-Amin, Bézier, Chen, Chernichenko, Cui, Erker, Faizi, Fujihara, Gevorgyan, Guo, He, Jacobsen, Kehr, Kim, Komeyama, Komeyama, Legare, Liedtke, Liu, Mahdi, Maitlis, Mandal, Melen, Mitu, Mochida, Nicasio, Oestreich, Parveen, Piers, Rajeev, Rosenthal, Satoh, Sinha, Stephan, Tamke, Tu, Tussing, Warner, Welch, Wilkins, Wilkins, Wilkins, Yu, Yuan, Zhang, Zhao, Zhao, Zuccaccia   +47 more
core   +2 more sources

Fluorine‐Free Ionic Liquid Electrolytes Featuring Biomass‐Derived Heterocyclic Anions for Variable Temperature Supercapacitors

Advanced Energy and Sustainability Research, Volume 7, Issue 2, February 2026.
This study introduces two new fluorine‐free ionic liquids (ILs) produced by coupling biomass‐derived heterocyclic anions, i.e., THP and 3‐FuA, with P4444 cation. Both the ILs display enhanced capacitance with increasing temperature, underscoring their potential as fluorine‐free electrolytes for supercapacitors.
Gaurav Tatrari, Sayantika Bhakta, Mukhtiar Ahmed, Solomon Tesfalidet, Faiz Ullah Shah   +4 more
wiley   +1 more source

Synthesis and chemical properties of 3-acyl- and 3-carbethoxy-4-pyrones [PDF]

, 2013
Реакция 1-арил-2-диметиламинометиленбутан-1,3-дионов с диэтиоксалатом в присутствии гидрида натрия в ТГФ приводит к образованию этил 5-ароил-4-оксо-4Н-пиран-2- карбоксилатам, из которых 4-оксо-6-арил-4Н-пиран-2-карбоновые кислота (6- арилкомановая ...
Obydennov, D. L., Обыденнов, Д. Л.   +1 more
core  

Synthesis of α‐Pentafluorosulfanylated‐β2,3‐Amino Esters

ChemistryEurope, Volume 4, Issue 2, February 2026.
De novo α‐SF5‐β2,3‐amino esters are now accessible through a straightforward aza‐Michael reaction using a series of newly developed (E)‐α‐SF5‐α,β‐unsaturated esters. Two new, highly functionalized, contiguous tertiary stereocenters are formed with diastereodivergence governed by the choice of solvent and/or base.
Thi Mo Nguyen, Guilhem Colomer, Oscar Maugue‐Sauze, Nicolas Blanchard, Vincent Bizet, Dominique Cahard   +5 more
wiley   +1 more source

Study on the Lewis Acid-promoted Aza-Diels - Alder Reaction of Azetidin-2-one-tethered Imines with Siloxydienes in the Asymmetric Synthesis of 2-Aryl(alkyl)-2,3-dihydro-4-pyridones [PDF]

, 2008
trans-3-Amino-b-lactams were evaluated as the chiral building blocks in the aza-Diels – Alder reaction of azetidin-2-one-tethered imines with siloxydienes under Lewis acid catalysis, as a route for the asymmetric synthesis of 2-aryl(alkyl)-2,3-dihydro ...
Habuš, Ivan, Margetić, Davor, Molčanov, Krešimir, Poljak, Tanja   +3 more
core   +1 more source