نتایج جستجو برای: 10 disubstituted anthracene derivatives
تعداد نتایج: 1119293 فیلتر نتایج به سال:
We report efficient Pd-catalyzed cyclizations of oxime esters with 1,1-disubstituted alkenes as the basis of a general entry to α,α-disubstituted pyrrolidine derivatives. We also demonstrate that catalytic asymmetric variants of this chemistry are feasible by employing a suitable chiral ligand.
The coupling of an acyl chloride with an isocyanide affords 2,5-disubstituted oxazoles under mild basic conditions instead of 4,5-disubstituted derivatives when using Schöllkopf conditions (butyllithium); this reaction constitutes a remarkable example of a base-induced chemoselective process in isocyanide chemistry.
The reaction of N,N’-persubstituted selenoacrylamides with alkyl bromoacetates gives rise to the formation of alkyl derivatives of N,N-disubstituted 2-aminoselenophene-5-carboxylates which can be transformed by saponification into corresponding 5-carboxylic acids. These compounds decompose by heating under formation of hitherto unknown N,N-disubstituted 2-amino-5H-selenophenes their spectral an...
Reactions of N-isocyaniminotriphenylphosphorane with α- chloroketones in the presence ofaromatic carboxylic acids proceed smoothly at room temperature and in neutral conditions toafford new disubstituted 1,3,4-oxadiazole derivatives in high yields.
The strict application of IUPAC rules for the numbering of tropane alkaloids is not always applied by authors and there is hence a lot of confusion in the literature. In most cases, the notation of 3, 6/7-disubstituted derivatives has been chosen arbitrarily, based on NMR and MS data, without taking into account the absolute configuration of these two carbons. This paper discusses the problem a...
A versatile method for the synthesis of chiral 1,4-disubstituted-1,2,3-triazole derivatives starting from easily accessible naturally occurring D-or L-amino acids as chiral synthons is described. The amino acids were converted into azido alcohols, followed by copper catalyzed [3+2] cycloaddition reactions between the azido alcohols and methyl propiolate and subsequent ester aminolysis with prim...
Several kinds of compounds available as model systems to investigation on metal-metal interaction in metalloproteins and on interaction of aromatics with nucleobases in arene intercalation to DNA were synthesized and characterized by spectrometry. Double and triple layered porphyrinophanes linked with 1,1'- or 1,3-disubstituted ferrocene moieties and their iron and cobalt complexes were prepare...
Antioxidant treatments have been expected to be a novel therapeutics for various oxidative stress-mediated disorders. Our previous study revealed that 5-hydroxyoxindole and its 3-phenacyl-3-hydroxy derivatives showed excellent antioxidant activities such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and lipid-peroxidation inhibitory activity. However, the DPPH radical scav...
Eleven derivatives of 7,12-dimethylbenz(a)anthracene were tested for carcinogenicity in Sprague-Dawley female rats by the s.c. injection of 1.0 or 0.1 mg of compound dissolved in 0.1 ml of sesame oil on alternate days for 20 doses. Eight derivatives [7-hydroxymethyl-12-methyl-, 7-formyl-l 2-methyl-, 7-methoxymethyl-l 2-methyl-, 7-acetoxymethyl-l 2-methyl-, 7-benzoyloxymethyl-l 2-methyl-. 7-iodo...
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