scholarly journals Efficient Electrochemical N-Alkylation of N-Boc-Protected 4-Aminopyridines: Towards New Biologically Active Compounds

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Marta Feroci ◽  
Isabella Chiarotto ◽  
Gianpiero Forte ◽  
Giovanna Simonetti ◽  
Felicia Diodata D'Auria ◽  
...  
Keyword(s):  
High Reactivity ◽  
Alkyl Halides ◽  
Biologically Active ◽  
Direct Reaction ◽  
Antiprotozoal Activity ◽  
Subsequent Reaction ◽  
Mild Conditions ◽  
High Yields ◽  
By Products ◽  
Very High

The use of electrogenerated acetonitrile anion allows the alkylation of N-Boc-4-aminopyridine in very high yields, under mild conditions and without by-products. The high reactivity of this base is due to its large tetraethylammonium counterion, which leaves the acetonitrile anion “naked.” The deprotection of the obtained compounds led to high yields in N-alkylated 4-aminopyridines. Nonsymmetrically dialkylated 4-aminopyridines were obtained by subsequent reaction of monoalkylated ones with t-BuOK and alkyl halides, while symmetrically dialkylated 4-aminopyridines were obtained by direct reaction of 4-aminopyridine with an excess of t-BuOK and alkyl halides. Some mono- and dialkyl-4-aminopyridines were selected to evaluate antifungal and antiprotozoal activity; the dialkylated 4-aminopyridines 3ac, 3ae and 3ff showed antifungal towards Cryptococcus neoformans; whereas 3cc, 3ee and 3ff showed antiprotozoal activity towards Leishmania infantum and Plasmodium falciparum.

scholarly journals Direct Sulfoxidation of Aromatic Methyl Thioethers with Aryl Halides by Copper-Catalyzed C(sp3)–H Bond Activation

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 105
Author(s):  
Runsheng Xu ◽  
Yueer Zhu ◽  
Feixiang Xiong ◽  
Suli Tong
Keyword(s):  
Bond Activation ◽  
Bond Formation ◽  
Aryl Halides ◽  
Biologically Active ◽  
Mild Conditions ◽  
Methyl Thioethers ◽  
High Yields

A copper-catalyzed direct sulfoxidation reaction by C(sp3)–H bond activation has been developed. Starting from sample aromatic methyl thioethers with aryl halides, versatile biologically-active arylbenzylsulfoxide derivatives were efficiently synthesized in good to high yields under mild conditions. This new methodology provides an economical approach toward C(sp3)–C(sp2) bond formation.

Additive- and Oxidant-Free Expedient Synthesis of Benzimidazoles Catalyzed by Cobalt Nanocomposites on N-Doped Carbon

Synlett ◽  
2019 ◽  
Vol 30 (03) ◽  
pp. 319-324 ◽  
Author(s):  
Zhaozhan Wang ◽  
Tao Song ◽  
Yong Yang
Keyword(s):  
Functional Group ◽  
Direct Synthesis ◽  
Biologically Active ◽  
One Pot ◽  
Mild Conditions ◽  
Wide Range ◽  
High Yields

A one-pot direct synthesis of a wide range of biologically active benzimidazoles through coupling of phenylenediamines and aldehydes catalyzed by a highly recyclable nonnoble cobalt nanocomposite was developed. A broad set of benzimidazoles can be efficiently synthesized in high yields and with good functional-group tolerance under additive- and oxidant-free mild conditions. The catalyst can be easily recycled for successive uses, and the process permits gram-scale syntheses of benzimidazoles.

Metal(II) Schiff base complexes as catalysts for the high-regioselective conversion of epoxides to β-hydroxy nitriles in glycol solvents

2006 ◽  
Vol 84 (11) ◽  
pp. 1575-1579 ◽  
Author(s):  
Hossein Naeimi ◽  
Mohsen Moradian
Keyword(s):  
Schiff Base ◽  
Ring Opening ◽  
Potassium Cyanide ◽  
Biologically Active ◽  
Schiff Base Complexes ◽  
Mild Conditions ◽  
Ring Opening Of Epoxides ◽  
Facile Preparation ◽  
High Yields

A facile preparation of 3-hydroxy propanenitrile derivatives is described involving ring opening of epoxides with potassium cyanide in glycol solvents in the presence of Schiff base complexes as catalysts. This method occurs under neutral and mild conditions with high yields and high regioselectivity. Thus, several β-Hydroxy nitriles, useful intermediates toward biologically-active molecules, are easily obtained at room temperature.Key words: β-hydroxy nitrile, Schiff base, epoxide, glycol, catalyst.

scholarly journals Pd-catalyzed asymmetric Suzuki–Miyaura coupling reactions for the synthesis of chiral biaryl compounds with a large steric substituent at the 2-position

2020 ◽  
Vol 16 ◽  
pp. 966-973
Author(s):  
Yongsu Li ◽  
Bendu Pan ◽  
Xuefeng He ◽  
Wang Xia ◽  
Yaqi Zhang ◽  
...  
Keyword(s):  
Steric Hindrance ◽  
Coupling Reactions ◽  
Mild Conditions ◽  
Axially Chiral ◽  
High Yields ◽  
Very High ◽  
Significant Superiority ◽  
Biaryl Compounds

Pd-catalyzed asymmetric Suzuki–Miyaura couplings of 3-methyl-2-bromophenylamides, 3-methyl-2-bromo-1-nitrobenzene and 1-naphthaleneboronic acids have been successfully developed and the corresponding axially chiral biaryl compounds were obtained in very high yields (up to 99%) with good enantioselectivities (up to 88% ee) under mild conditions. The chiral-bridged biphenyl monophosphine ligands developed by our group exhibit significant superiority to the naphthyl counterpart MOP in both reactivity and enantioselectivity control. The large steric hindrance from π-conjugated ortho-substituents of the bromobenzene substrates and the Pd···O interaction between carbonyl and palladium seem essential to achieve high enantioselectivity.

The Synthesis of (Iodobenzyl)oxybenzaldehydes, Useful Intermediates for Biologically Active Targets

2016 ◽  
Vol 14 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Hedvig Bölcskei ◽  
Andrea Német-Hanzelik ◽  
István Greiner ◽  
Zsófia Dubrovay ◽  
Viktor Háda ◽  
...  
Keyword(s):  
Reaction Time ◽  
Double Bond ◽  
High Resolution ◽  
New Products ◽  
Biologically Active ◽  
Side Reactions ◽  
Channel Blockers ◽  
Voltage Gated ◽  
High Yields ◽  
By Products

The benzyloxy-benzyl moiety is a valuable building block in medicinal chemistry, e.g. in case of the voltage gated sodium channel blockers Safinamide and Ralfinamide. To prepare further derivatives a series of (iodobenzyl)oxybenzaldehydes (3a-3i) useful intermediates for the synthesis of biologically active compounds were synthesized in high yields by O-benzylation of 2-, 3- and 4- hydroxybenzaldehydes (2a-2c) with a variety of iodobenzylbromides (1a-1c). The title compounds were obtained in 77-100 % yield in 2-5 hours. Longer reaction time or addition of water favoured the formation of aldol-type by-products, mainly 4-hydroxy-4-{[(iodophenyl)methoxy]phenyl}butan-2-one derivatives (5a-5g), which contained the iodine group and the 4-hydroxy-butan-2-one moiety in various positions. In one case (3E-)-4-{3-[(2-iodophenyl)methoxy]phenyl}but-3-en-2-one (6c) with a double bond has been isolated. These side-reactions could be avoided by using acetonitrile as solvent. The structures of the new products were established by high resolution MS and NMR measurements, where 1H-1H, direct 1H-13C, long-range 1H-13C scalar spin-spin connectivities were established from 1D 1H, 13C, 2D gHSQCAD, zTOCSY and gHMBCAD NMR experiments.

scholarly journals Whey as a raw material for the production of functional beverages

2012 ◽  
Vol 66 (4) ◽  
pp. 567-579 ◽  
Author(s):  
Maja Bulatovic ◽  
Marica Rakin ◽  
Ljiljana Mojovic ◽  
Svetlana Nikolic ◽  
Maja Vukasinovic-Sekulic ◽  
...  
Keyword(s):  
Food Industry ◽  
World Market ◽  
Raw Material ◽  
Effective Solution ◽  
Way Of Life ◽  
Food Shortages ◽  
Functional Beverages ◽  
High Yields ◽  
By Products ◽  
Very High

One of the least utilized by-products of food industry, despite the great potential that is described, is the whey, which is obtained as a by-product of the technological process production of cheese and casein. The excess whey, which occurs in this process in very high yields, with failure to processing is becoming a very big polluter, what is completely at odds with the potential that such materials possess. On the other hand, the modern tempo and way of life, and increasingly polluted environmental also, impose the need to produce food products that would help the human body in the fight against harmful agents which are exposed to daily. One of the more effective solution is the production of fermented functional beverages based on whey, which achieved this intention in the most natural and most comfortable way. Considering the rather untapped potential of whey as a raw material and growing food shortages in the world market, the aim of this study was to analyze the possibilities of production of functional beverages based on whey, with satisfactory sensory characteristics, in order to demonstrate the attractiveness of whey as raw material in the food industry. This paper presents an overview of the wide possibilities for the use of whey with a special emphasis on its attractiveness and the necessity of its utilizing.

scholarly journals Construction of Unusual Indole-Based Heterocycles from Tetrahydro-1H-pyridazino[3,4-b]indoles

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4124
Author(s):  
Cecilia Ciccolini ◽  
Lucia De Crescentini ◽  
Fabio Mantellini ◽  
Giacomo Mari ◽  
Stefania Santeusanio ◽  
...  
Keyword(s):  
Biologically Active ◽  
Indole Derivatives ◽  
Chromatographic Purification ◽  
Mild Conditions ◽  
Pyridazine Ring ◽  
High Yields ◽  
Structural Connection ◽  
Hydrolysis Of ◽  
Active Natural ◽  
Easy Operation

Herein, we report the successful syntheses of scarcely represented indole-based heterocycles which have a structural connection with biologically active natural-like molecules. The selective oxidation of indoline nucleus to indole, hydrolysis of ester and carbamoyl residues followed by decarboxylation with concomitant aromatization of the pyridazine ring starting from tetrahydro-1H-pyridazino[3,4-b]indole derivatives lead to fused indole-pyridazine compounds. On the other hand, non-fused indole-pyrazol-5-one scaffolds are easily prepared by subjecting the same C2,C3-fused indoline tetrahydropyridazines to treatment with trifluoroacetic acid (TFA). These methods feature mild conditions, easy operation, high yields in most cases avoiding the chromatographic purification, and broad substrate scope. Interestingly, the formation of indole linked pyrazol-5-one system serves as a good example of the application of the umpolung strategy in the synthesis of C3-alkylated indoles.

Selective Synthesis of Carbonates from Glycerol, CO2, and Alkyl Halides Using tert-Butyltetramethylguanidine

Synlett ◽  
2018 ◽  
Vol 29 (13) ◽  
pp. 1759-1764
Author(s):  
Masatoshi Mihara ◽  
Kaname Moroga ◽  
Tetsuo Iwasawa ◽  
Takeo Nakai ◽  
Takatoshi Ito ◽  
...  
Keyword(s):  
High Efficiency ◽  
Value Added ◽  
Alkyl Halides ◽  
Selective Synthesis ◽  
Guanidine Group ◽  
Mild Conditions ◽  
Methyl Carbonate ◽  
By Products ◽  
Value Added Products

Herein, we describe the guanidine-promoted synthesis of carbonates from glycerol, CO2, and alkyl halides. Specifically, a linear tricarbonate (1,2,3-tri-O-butoxycarbonylglycerol), a dicarbonate [butyl (2-oxo-1,3-dioxolan-4-yl)methyl carbonate] containing a linear and a cyclic moiety, and a cyclic monocarbonate (4-hydroxymethyl-2-oxo-1,3-dioxolan) were selectively obtained in good yields, which were strongly affected by the steric bulkiness of the guanidine group substituents. The developed method exhibits the advantages of high efficiency and mild conditions, thus being a powerful tool for the synthesis of value-added products from industrial by-products.

scholarly journals Efficient Production of Poly(Cyclohexene Carbonate) via ROCOP of Cyclohexene Oxide and CO2 Mediated by NNO-Scorpionate Zinc Complexes

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2148
Author(s):  
Sonia Sobrino ◽  
Marta Navarro ◽  
Juan Fernández-Baeza ◽  
Luis F. Sánchez-Barba ◽  
Agustín Lara-Sánchez ◽  
...  
Keyword(s):  
Ring Opening ◽  
Zinc Complexes ◽  
Efficient Production ◽  
Cyclohexene Oxide ◽  
X Ray Diffraction ◽  
Co Catalyst ◽  
X Ray ◽  
Mild Conditions ◽  
High Yields ◽  
Very High

New mono- and dinuclear chiral alkoxide/thioalkoxide NNO-scorpinate zinc complexes were easily synthesized in very high yields, and characterized by spectroscopic methods. X-ray diffraction analysis unambiguously confirmed the different nuclearity of the new complexes as well as the variety of coordination modes of the scorpionate ligands. Scorpionate zinc complexes 2, 4 and 6 were assessed as catalysts for polycarbonate production from epoxide and carbon dioxide with no need for a co-catalyst or activator under mild conditions. Interestingly, at 70 °C, 10 bar of CO2 pressure and 1 mol % of loading, the dinuclear thioaryloxide [Zn(bpzaepe)2{Zn(SAr)2}] (4) behaves as an efficient and selective one-component initiator for the synthesis of poly(cyclohexene carbonate) via ring-opening copolymerization of cyclohexene oxide (CHO) and CO2, affording polycarbonate materials with narrow dispersity values.

Discotic liquid crystals of transition metal complexes 47: synthesis of phthalocyanine-fullerene dyads showing spontaneous homeotropic alignment

2012 ◽  
Vol 16 (12) ◽  
pp. 1261-1275 ◽  
Author(s):  
Tenpei Kamei ◽  
Takayuki Kato ◽  
Eiji Itoh ◽  
Kazuchika Ohta
Keyword(s):  
Transition Metal Complexes ◽  
Liquid Crystalline ◽  
Discotic Liquid Crystals ◽  
Temperature Dependent ◽  
X Ray ◽  
Bingel Reaction ◽  
Homeotropic Alignment ◽  
High Yields ◽  
By Products ◽  
Very High

In previous work, we successfully synthesized the first columnar liquid crystalline 1:1 phthalocyanine(Pc)-fullerene( C60 ) dyad, C12(OMalC60)PcCu (4), showing spontaneous homeotropic alignment, by using Bingel reaction. However, it gave undesirable 2:1 and 3:1 Pc- C60 by-products at the same time, so that the 1:1 Pc- C60 dyad (4) could be obtained in a very low yield (20%). On the other hand, in this work we have prepared novel Pc- C60 dyads, C12(OFbaC60)PcM (8: M = Co (a), Ni (b) and Cu (c)), by using Prato reaction. Very interestingly, it gave almost only the target 1:1 Pc- C60 dyads 8a–8c in very high yields (81–96%) with negligible amount of Pc- C60 by-products. These dyads 8a–8c and the precursor Pc derivatives were characterized by polarizing microscope, differential scanning calorimeter and temperature-dependent X-ray diffractometer. Thus, it was revealed that each of the dyads and precursors shows spontaneous homeotropic alignment in their Coltet mesophase.

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