16728-64-6Relevant academic research and scientific papers
Highly efficient nitrobenzene and alkyl/aryl azide reduction in stainless steel jars without catalyst addition
Martina, Katia,Baricco, Francesca,Tagliapietra, Silvia,Moran, Maria Jesus,Cravotto, Giancarlo,Cintas, Pedro
supporting information, p. 18881 - 18888 (2018/11/26)
The mechanochemical and selective reduction of aryl nitro and aryl/alkyl azide derivatives, with either formate salts or hydrazine, to the corresponding, synthetically useful amines occurs in excellent yields in a planetary ball mill without the addition of a catalyst. This newly developed and solvent-free protocol is efficient, fast and does not require the addition of a metal hydrogenation catalyst as the stainless steel jar itself fulfils that role. The method has been applied to a broad range of compounds and excellent yields have been obtained. The formylation of alkyl amines has been successfully performed, by means of mechanochemical activation, in the presence of ammonium formate alone.
Chemo- and Site-Selective Alkyl and Aryl Azide Reductions with Heterogeneous Nanoparticle Catalysts
Udumula, Venkatareddy,Nazari, S. Hadi,Burt, Scott R.,Alfindee, Madher N.,Michaelis, David J.
, p. 4423 - 4427 (2016/07/12)
Site-selective modification of bioactive natural products is an effective approach to generating new leads for drug discovery. Herein, we show that heterogeneous nanoparticle catalysts enable site-selective monoreduction of polyazide substrates for the generation of aminoglycoside antibiotic derivatives. The nanoparticle catalysts are highly chemoselective for reduction of alkyl and aryl azides under mild conditions and in the presence of a variety of easily reduced functional groups. High regioselectivity for monoazide reduction is shown to favor reduction of the least sterically hindered azide. We hypothesize that the observed selectivity is derived from the greater ability of less-hindered azide groups to interact with the surface of the nanoparticle catalyst. These results are complementary to previous Staudinger reduction methods that report a preference for selective reduction of electronically activated azides.
An Iodine-Catalyzed Hofmann-L?ffler Reaction
Martínez, Claudio,Mu?iz, Kilian
supporting information, p. 8287 - 8291 (2015/07/07)
Iodine reagents have been identified as economically and ecologically benign alternatives to transition metals, although their application as molecular catalysts in challenging C-H oxidation reactions has remained elusive. An attractive iodine oxidation catalysis is now shown to promote the convenient conversion of carbon-hydrogen bonds into carbon-nitrogen bonds with unprecedented complete selectivity. The reaction proceeds by two interlocked catalytic cycles comprising a radical chain reaction, which is initiated by visible light as energy source. This unorthodox synthetic strategy for the direct oxidative amination of alkyl groups has no biosynthetic precedence and provides an efficient and straightforward access to a general class of saturated nitrogenated heterocycles.
Synthesis and antiviral activity of helioxanthin analogues
Yeo, Hosup,Li, Ying,Fu, Lei,Zhu, Ju-Liang,Gullen, Elizabeth A.,Dutschman, Ginger E.,Lee, Yashang,Chung, Raymond,Huang, Eng-Shang,Austin, David J.,Cheng, Yung-Chi
, p. 534 - 546 (2007/10/03)
A series of natural product analogues based on helioxanthin (2), with particular attention to modification of the lactone ring and methylenedioxy group, were synthesized and evaluated for their antiviral activities. Among them, lactam derivative 18 and helioxanthin cyclic hydrazide 28 exhibited significant in vitro antiviral activity against hepatitis B virus (EC 50 = 0.08 and 0.03 μM, respectively). Compound 18 showed the most potent antiviral activity against hepatitis C virus (55% inhibition at 1.0 μM). Compound 12, an acid-hydrolyzed product of helioxanthin cyclic imide derivative 9, was found to exhibit broad-spectrum antiviral activity against hepatitis B virus (EC50 = 0.8 μM), herpes simplex virus type 1 (EC50 = 0.15 μM) and type 2 (EC50 50 = 9.0 μM), and cytomegalovirus (EC 50 = 0.45 μM). Helioxanthin lactam derivative 18 also showed marked inhibition of herpes simplex virus type 1 (EC50 = 0.29 μM) and type 2 (EC50 = 0.16 μM). The cyclic hydrazide derivative of helioxanthin 28 and its brominated product 42 exhibited moderately potent activities against human immunodeficiency virus (EC50 = 2.7 and 2.5 μM, respectively). Collectively, these molecules represent a novel set of antiviral compounds with unique structural features.
NOVEL ANTIVIRAL HELIOXANTHIN ANALOGS
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Page/Page column 40-41, (2010/02/14)
The present invention relates to novel antiviral helioxanthin analogs. These compounds may particularly be used alone or in combination with other drugs for the treatment of the following: hepadnaviruses, flaviviruses, herpesviruses and human immunodefici
Synthesis of Poly(propyl ether imine) Dendrimers and Evaluation of Their Cytotoxic Properties
Krishna, Thatavarathy Rama,Jayaraman, Narayanaswamy
, p. 9694 - 9704 (2007/10/03)
In this paper, we report the synthesis of several poly(propyl ether imine) dendrons and dendrimers. These dendrons and dendrimers were constructed by involving an ether as the linker component and an imine as the branching component. The divergent syntheses of dendrons and dendrimers were established with the aid of two alternate Michael addition reactions and two alternate reduction reactions in a four-step iterative synthetic sequence. Dendrons up to three generations were synthesized and some of the dendrons were attached to a benzenoid core so as to obtain dendrimers up to two generations containing 12 carboxylic acids at the periphery. Divergent synthesis involving ether as the core was found to be more facile, and dendrimers up to three generations having 16 carboxylic acids at the periphery were achieved in good to excellent yields in each individual step. The adopted synthetic sequence allows us to install either alcohol, an amine, or a carboxylic acid at their peripheries. The carboxylic acid-terminated dendrons and dendrimers were evaluated as to their cytotoxic properties, and while most dendrons and dendrimers did not exhibit any measurable cytotoxicity, even up to 100/μg/mL, the second-generation dendrimer with the benzenoid core exhibited a mild toxicity at concentrations above 30/μg/mL.
Piperidine derivatives having renin inhibiting activity
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, (2008/06/13)
Novel piperidine derivatives, their manufacture and use as medicaments, are disclosed. The invention is concerned with the novel piperidine derivatives of general formula I wherein R1, R2, R3, R4, Q, X, Z, m and n are as described herein.
Synthesis of a series of trifluoromethylazoles and determination of pKa of acidic and basic trifluoromethyl heterocycles by 19F NMR spectroscopy
Jones, Brian G.,Branch, Sarah K.,Thompson, Andrew S.,Threadgill, Michael D.
, p. 2685 - 2692 (2007/10/03)
Trifluoroacetylation at the 5-position of 3,4-dihydro-2H-pyran and the 3-position of 4,5-dihydrofuran, followed by treatment with hydrazine, gave 3-(3-trifluoromethyl-1H-pyrazol-4-yl)propanol and 2-(3-trifluoromethyl-1H-pyrazol-4-yl)ethanol, respectively.In the latter case, an intermediate dimer was isolated.Isomeric 2-(3-trifluoromethyl-1H-pyrazol-5-yl)ethanol was formed by reaction of hydrazine with 6-benzyloxy-1,1,1-trifluorohex-3-yn-2-one and deprotection.Reaction of 3-benzyloxypropylamine with 2,5-bis(trifluoromethyl)-1,3,4-oxadiazole, followed by deprotection, afforded 3-propanol.A series of 2-trifluoromethyl-1H-benzimidazoles and 2-trifluoromethyl-3H-imidazopyridines were prepared by condensation of the appropriate ortho-arenediamine with trifluoroacetic acid.Analysis of the 19F NMR spectra of the trifluoromethylazoles and of 3-trifluoromethylpyridine in aqueous solution at different pHs enabled determination of pKa values.All the compounds evaluated had one or more pKa between 1 and 13, except the triazole.Several compounds were identified as having potential use in measuring pH in biological media by 19F NMR spectroscopy.
Selective O-benzylation of aminoalkanols
Hu,Cassady
, p. 907 - 913 (2007/10/02)
A simple and one-step method has been developed for selective O-benzylation of aminoalkanols. Study of steric effects shows the best selectivity in adjacent 1°-OH vs 2°-CHNH2 and decreased selectivity in 2°-OH vs 1°-CH2NH2 and non adjacent aminoalkanol.
Polycyclic amines and intermediates therefor
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, (2008/06/13)
This invention relates to a new method for the preparation of amines containing alkylene groups by using cyclic alkylene sulphuric esters, and novel intermediates for use in the method. The new method is useful for preparation of i.a. pharmaceuticals. The novel intermediates are useful i.a. as surfactants.
