Results 71 to 80 of about 12,662 (287)

Copper-catalysed asymmetric allylic alkylation of alkylzirconocenes to racemic 3,6-dihydro-2H-pyrans

Beilstein Journal of Organic Chemistry, 2015
Asymmetric allylic alkylation is a powerful reaction that allows the enantioselective formation of C–C bonds. Here we describe the asymmetric alkylation of alkylzirconium species to racemic 3,6-dihydro-2H-pyrans.
Emeline Rideau, Stephen P. Fletcher
doaj   +1 more source

5,6-Dihydro-2H-pyran-3(4H)-on als Baustein zur Synthese pyrananellierter Heterocyclen [PDF]

, 1984
Während 5,6-Dihydro-2H-pyran-3(4H)-on (3) sich mit ortho-substituierten Phenylcarbonylverbindungen nur in Einzelfällen regioselektiv zu pyrananellierten Heterocyclen umsetzt - z. B.
Eiden, Fritz, Wanner, Klaus Th.
core   +1 more source

Comprehensive Characterization of Acer truncatum Leaf Extract: Identification of Systemic Metabolites and Effects on Performance, Antioxidant Status, and Intestinal Microbiota in Laying Hens

Animal Research and One Health, EarlyView.
Dietary A. truncatum leaf extract is absorbed and improves laying performance in aged hens by enhancing systemic antioxidant capacity and modulating the gut microbiota. ABSTRACT The demand for natural feed additives is considerably increasing in the antibiotic‐free feed era.
Kailong Qin, Jiantao Yang, Minglu Gao, Xiaozhao Tao, Xin Yang, Yanli Liu, Xiaojun Yang   +6 more
wiley   +1 more source

Synthesis of tacrine analogues derived from n-aryl-5-amino-4-cyanopyrazoles [PDF]

, 2008
Synthesis of eleven tacrine analogues derived from N-aryl-5-amino-4-cyanopyrazoles, by a Friedländer type reaction, is described. Their structures were confirmed by 1H and 13C NMR spectroscopy, elemental analysis and/or mass spectrometry.Fundação para a ...
Abdellatif M. Salaheldin, Ana M. F. Oliveira-Campos, Carla S. Francisco, Lígia M. Rodrigues, Michalson E. T., Thomae D.   +5 more
core   +1 more source

Fluorescent Diarylethenes With Polar Groups: Synthesis, Spectra, and Optical Microscopy Applications

Chemistry – A European Journal, EarlyView.
Blinking green and flashing red: photo‐switchable and photo‐activatable probes emitting green and red light were prepared and applied as bioconjugates in super‐resolution optical microscopy. ABSTRACT The use of photoactivatable fluorescent diarylethenes (fDAEs) in biology‐related light microscopy has been restricted by the lack of probes having freely ...
Kakishi Uno, Sven Nagorny, Ayse Aktalay, Dojin Kim, Mariano L. Bossi, Vladimir N. Belov, Stefan W. Hell   +6 more
wiley   +1 more source

Meglumine catalyzed one-pot green synthesis of novel 4,7-dihydro-1H-pyrazolo3,4-bpyridin-6-amines [PDF]

, 2017
Meglumine efficiently catalyzes the one-pot, five-component reaction of hydrazine, ethyl acetoacetate, aryl aldehydes, substituted phenylacetonitriles and ammonium acetate in ethanol at room temperature to afford novel 4,7-dihydro-1H-pyrazolo3,4-bpyridin-
Govindaraju, S., Khan, R.-U.-R., Pasha, M.A., Tabassum, S.   +3 more
core   +1 more source

A General Strategy for the Synthesis of Jerangolids Enabled by π‐allyl Stille Coupling

Chemistry – A European Journal, EarlyView.
A general strategy for the synthesis of jerangolids is established, featuring a late‐stage π‐allyl Stille coupling of two advanced, highly customizable building blocks to form the skipped diene core. The approach provides access to all naturally occurring jerangolids, including jerangolid H, whose configuration is confirmed by NMR analysis.
Janick Schug, Bernd Morgenstern, Johann Jauch   +2 more
wiley   +1 more source

An analysis of double exposure lithography options [PDF]

, 2008
The current optical photolithography technology is approaching the physical barrier to the minimum achievable feature size. To produce smaller devices, new resolution enhancement technologies must be developed.
Byers, Jeffrey, Jen, Kane, Lee, Saul, Rice, Bryan, Turro, Nicholas J., Willson, C. Grant, Zimmerman, Paul   +6 more
core   +2 more sources

Neue Versuche mit Spiropyran: Photometrie, NMR‐Spektroskopie und On‐Water‐Synthese

CHEMKON, EarlyView.
Reaktionskinetik wird häufig als schwierig, theoretisch und Mathematik‐lastig empfunden, weshalb experimentelle Zugänge für diesem Themenbereich notwendig sind. In diesem Beitrag werden entsprechende Versuche zur Reaktionskinetik vorgestellt, bei denen das Farbstoffsystem eines Spiropyrans und dessen isomerer Merocyanin‐Form untersucht wird.
Marcel Emmert, Jordan Karg, Katja Flora Weirauch   +2 more
wiley   +1 more source

An Efficient, Simple and Green Zn(Phen)2Cl2 Complex Catalyzed Synthesis of 4-H-Benzo[b]pyrans in Water at Ambient Temperature

E-Journal of Chemistry, 2011
An efficient method for the synthesis of 4-H-benzo[b]pyrans has been developed by the use of Zn(Phen)2Cl2(2 mol%) as an ecofriendly catalyst. The mixture of an appropriate aldehyde, malononitrile and dimedone in the presence of the Zn(Phen)2Cl2 as an ...
E. Mosaddegh, A. Hassankhani, G. Mansouri   +2 more
doaj   +1 more source