Search results for "substitut"

ChemInform Abstract: Amphiphilic Dyes for Nonlinear Optics: Dependence of Second Harmonic Generation on Functional Group Substitution.

2010

ChemInform Abstract: Unique Regioselectivity in the C(sp3)-H α-Alkylation of Amines: The Benzoxazole Moiety as a Removable Directing Group.

2015

The benzoxazol-2-yl substituent is easily introduced by oxidative coupling or nucleophilic substitution and can be removed by hydroxide or by hydride reduction.

Synthese und biochemische Eigenschaften substituierter Phenoxy- und Anilino-1,3,5-triazine

1983

Die nucleophile Substitution eines Chloratoms in 2,4-Dichlor-6-diethylamino-1,3,5-triazin (1) durch die Hydroxyacetophenone 2a–c fuhrt zu den 2-Acetylphenoxy-4-chlor-6-diethylamino-1,3,5-triazinen 3a–c. Analog geht aus der Umsetzung von 1 mit 4-Fluoranilin (4a) das Monoanilinoderivat 5a hervor; dagegen bildet sich unter den gleichen Reaktionsbedingungen aus 1 und 2-Fluoranilin (4b) das Dianilinoderivat 5b. Strukturtyp 3 zeichnet sich durch antimykotische und Antiprotozoenwirksamkeit aus, wahrend 5 herbizide Wirkungen auszulosen vermag. Synthesis and Biochemical Properties of Substituted Phenoxy- and Anilino-1,3,5-triazines The nucleophilic substitution of one chlorine atom in 2,4-dichloro-6…

A new method for the regioselective synthesis of β-enamino acid derivatives

1993

Abstract A mild, simple and efficient route to β-enamino imidazole carbonilic derivatives 3 by reaction of ketimines with N,N′ -carbonyl diimidazole in the presence of boron triflouride as catalyst has been developed. The conversion of 3 to esters has also been explored.

The Photocatalytic Activity of Novel, Substituted Porphyrin/TiO2-Based Composites

2010

Four novel porphyrins, 5-[3-(3-phenoxy)-propoxy]phenyl porphyrin, 5,15-di-[3-(3-phenoxy)-propoxy] phenyl porphyrin, 5,10,15-tri-[3-(3-phenoxy)-propoxy]phenyl porphyrin, 5,10,15,20-tetra-[3-(3-phenoxy)- propoxy]phenyl porphyrin, and their corresponding Cu(II) porphyrins, were synthesized and characterized spectroscopically. The photodegradation of 4-nitrophenol in aq. suspension was used to determine the photocatalytic activity of polycrystalline TiO2 samples which had been impregnated with the Cu(II) porphyrins, as sensitizers. The photocatalytic activity of the composite depends mainly on the amount of sensitizer on the TiO2 surface rather than the nature of the substituted porphyrins.

N-Bromosuccinimide, Its Properties and Reactions The Course of Substitution

1964

Cyclam-strapped porphyrins and their iron(III)-copper(II) complexes as models for the resting state of cytochrome c oxidase

1999

International audience; The ESR study of two cyclam-strapped porphyrins in which, on one side, the cyclam is attached with a variable length linker to the porphyrin and, on the other side, a non-coordinating strap protects the iron from any intermolecular interaction, is reported. Variation of the linker length is made possible by the use of either a Michael reaction or a nucleophilic substitution, leading respectively to three or two carbon atom links. It is shown that in the case of the shortest link, the oxidized ironÈcopper complex exhibits a spin interaction. The distance between thetwo metal centers is evaluated to be around 4.5 Å, a value consistent with the one found in the natural …

Excited State N−H Tautomer Selectivity in the Singlet Energy Transfer of a Zinc(II)-Porphyrin-Truxene-Corrole Assembly

2017

International audience; An original corrole-containing polyad for S-1 energy transfer, in which one zinc(II)-porphyrin donor is linked to two free-base corrole acceptors by a truxene linker, is reported. This polyad exhibits a rapid zinc(II)-porphyrin*free-base corrole transfer (4.83x10(10)s(-1); 298K), even faster than the tautomerization in the excited state processes taking advantage of the good electronic communication provided by the truxene bridge. Importantly, the energy transfer process shows approximately 3-fold selectivity for one corrole N-H tautomer over the other even at low temperature (77K). This selectivity is due to the difference in the J-integral being effective in both t…

Hair Cortisol Concentration as a Biomarker of Sleep Quality and Related Disorders

2021

Cortisol is the end product of the hypothalamic-pituitary-adrenal (HPA) axis, and its production is increased mainly in stressful situations or in chronic disorders accompanied by stress enhancement. Altered cortisol concentrations have been reported in a number of neuropsychiatric diseases and sleep disorders. Cortisol concentrations have been measured using several methods, and in several matrixes, such as blood, saliva, and urine. However, lately, hair cortisol, for several reasons, has emerged as a promising biomarker of long-term retrospective HPA activation. Several experimental approaches for cortisol measurement with the corresponding concentration reference ranges and a summary of …

ON THE ONSET OF POST-COMMUNIST INDUSTRIAL DEVELOPMENT IN CENTRAL AND EAST EUROPEAN ECONOMIES

2013

In the course of the last twenty odd years, Central and East-European economies have been striving to reform an inherited flawed trade structure, in an attempt to increase their industrial competitiveness and improve their position within the international division of labor. The respective countries have gone through an industrial metamorphosis that swept away the legacy of socialist autarky, making them better-equipped to deal with globalization challenges. The dismantling of the COMECON forced CEEs to institute severe constraints on public budgets; as a consequence, the price of physical capital edged up relative to the price of labor thereby making the respective economies relative abund…