4441-66-1Relevant academic research and scientific papers
Visible light-induced selective generation of radicals from organoborates by photoredox catalysis
Yasu, Yusuke,Koike, Takashi,Akita, Munetaka
, p. 3414 - 3420 (2013/02/25)
A new strategy for the generation of carbon-centered radicals via oxidation of alkyl-, allyl-, benzyl- and arylborates by visible-light-driven single electron transfer (SET) photoredox catalysis has been established. The generated radicals smoothly react with TEMPO and electron-deficient alkenes to afford C-O and C-C coupling products, respectively. In this radical initiating system, cyclic organo(triol)borates turn out to be useful radical precursors.
2-Substituted histamines with G-protein-stimulatory activity
Detert, H.,Hagelueken, A.,Seifert, R.,Schunack, W.
, p. 271 - 276 (2007/10/02)
The cationic-amphiphilic 2-substituted histamines, 2-(2-chlorophenyl)histamine (2-ethanamine) and 2-(2-cyclohexylethyl)histamine, activate pertussis toxin-sensitive guanine nucleotide-binding proteins (G-proteins) of the Gi-subfamily by a receptor-independent mechanism.We studied structure-activity relationships of 2-substituted histamine derivatives for this G-protein activation using six known and 12 newly synthesized compounds.Elongation of the alkyl chain between imidazole and the ring system enhanced the potency and efficiency of substances in activating high-affinity GTP hydrolysis, ie the enzymatic activity of G-protein α subunits, in membranes of HL-60 leukemic cells.Cyclopentyl-, cyclohexyl- and norbornyl-substituted histamines were more effective and potent than phenyl-substituted histamines in mediating G-protein activation in HL-60 membranes and in activating reconstituted bovine brain Gi/Go-proteins.Our data show that the chain length and the type of ring system are important determinants for receptor-independent G-protein activation by 2-substituted histamines.With respect to histamine H1-receptors, most of the substances studied displayed weak antagonistic activity.
Synthesis and antiallergy activity of [1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-one derivatives. II. 6-Alkyl- and 6-cycloalkylalkyl derivatives
Yokohama,Miwa,Aibara,Fujiwara,Matsumoto,Nakayama,Iwamoto,Mori,Moroi,Tsukada,Isoda
, p. 2391 - 2398 (2007/10/02)
A series of 6-alkyl- or 6-(cycloalkylalkyl)-[1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyr imidin-9(3H)-ones 1b-o was synthesized from the corresponding 1,3,4-thiadiazol-5-amines 3b-o and the antiallergic activities of the products were evaluated. Among the compounds 6-(2-cyclohexylethyl)-[1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]p yrimidin-9(3H)-one 1h, whose X-ray crystallographic stereostructure is shown, was found to be a promising new antiallergic agent, which has low toxicity and dual activity as a leukotriene D4 receptor antagonist and as an orally active mast cell stabilizer.
EVALUATION OF TRIBUTYLGERMANIUM HYDRIDE AS A REAGENT FOR THE REDUCTIVE ALKYLATION OF ACTIVE OLEFINS WITH ALKYL HALIDES
Pike, Philip,Hershberger, Susan,Hershberger, James
, p. 6295 - 6304 (2007/10/02)
The reductive alkylation of acrylonitrile and of 2-cyclohexen-1-one by alkyl halides using tributylgermanium hydride was systematically evaluated.The performance of the germanium reagent was compared to that of the more commonly employed tributyltin hydride.For certain applications thegermanium reagent afforded improved yields without the use of large excess olefin concentrations.Disadvantages of the germanium reagent include a tendency to hydrogermylate active terminal olefins and a general low reactivity towards alkyl halide substrates.The following series of six other triorganotin and triorganogermanium hydrides were also briefly screened for possible application to reductive alkylations: trimesityltin hydride, trimesitylgermanium hydride, triphenyltin hydride, triphenylgermanium hydride, trineopentyltin hydride, and tricyclohexylgermanium hydride.
