44 research outputs found
Ruthenium-Catalyzed Synthesis of Benzoxazoles Using Acceptorless Dehydrogenative Coupling Reaction of Primary Alcohols with 2‑Aminophenol under Heterogeneous Conditions
An
efficient ruthenium-catalyzed acceptorless dehydrogenative coupling
reaction of primary alcohols with 2-aminophenol for one-pot synthesis
of benzoxazoles is introduced. The phosphine-functionalized magnetic
nanoparticles (PFMNPs; Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>@PPh<sub>2</sub>) as a magnetic recyclable phosphorus ligand in the
presence of Ru<sub>2</sub>Cl<sub>4</sub>(CO)<sub>6</sub> was found
to be an efficient heterogeneous catalytic system for promotion of
the designed protocol. The reaction was carried out efficiently with
a variety of substrates to give the corresponding products in moderate
to good yields
Magnetic, Acidic, Ionic Liquid-Catalyzed One-Pot Synthesis of Spirooxindoles
Magnetic, supported, acidic ionic
liquid was synthesized and identified
as an efficient catalyst for the one-pot synthesis of novel spirooxindole
derivatives at mild conditions and in good yields. Three component
reaction of wide variety of substituted isatins, 1,3-dimethyl-2-amino
uracil, and barbituric acid, thiobarbituric acid, and dimedon as 1,3-dicarbonyl
compounds gives the target compounds. Operational simplicity, low
cost, high yields, environmental friendliness, wide applicability
and reusability and easy recovery of the catalyst using an external
magnet are the key features of this methodology
<b>A solvent free and selective method for preparation of triphenylmethyl ethers of alcohols and nucleosides</b>
A very simple and efficient method is described for protection of alcohols and nucleosides with trityl(triphenylmethyl), mono and dimethoxytrityl chlorides in the presence of triethylamine under microwave irradiation. High selectivity was observed for tritylation of 5'-OH function of nucleosides
The Effects of Blood Sugar (Glucose) Metabolism on the Sleep and Memory via Diet and Medicine Therapy in Ahwaz Diabetic Patients
Synthesis of α‑Aminonitriles with Benzimidazolic and Theophyllinic Backbones Using the Strecker Reaction
An example of the
application of the Strecker reaction in the synthesis
of a new class of α-aminonitriles with benzimidazole and theophylline
backbones has been developed. For the synthesis of these compounds,
first 4-hydroxybenzaldehyde was reacted with 1,3- and 1,5-dibromides/epibromohydrin
to produce the corresponding bromo-substituted aldehydes. Then, benzimidazole/theophylline
was reacted with the latter to generate the related benzimidazolic/theophyllinic
aldehydes. Finally, the Strecker reactions of the synthetic benzimidazolic
and theophyllinic aldehydes with different amines afforded the target
products
Metal–Organic Framework MIL-101(Cr) as an Efficient Heterogeneous Catalyst for Clean Synthesis of Benzoazoles
A metal–organic framework
[MIL-101Â(Cr)] was used as an efficient
heterogeneous catalyst in the synthesis of benzoazoles (benzimidazole,
benzothiazole, and benzoxazole), and quantitative conversion of products
were obtained under optimized reaction conditions. The catalyst could
be simply extracted from the reaction mixture, providing an efficient
and clean synthetic methodology for the synthesis of benzoazoles.
The MIL-101Â(Cr) catalyst could be reused without a remarkable decrease
in its catalytic efficiency
Supported Palladium on Magnetic Nanoparticles–Starch Substrate (Pd-MNPSS): Highly Efficient Magnetic Reusable Catalyst for C–C Coupling Reactions in Water
A novel heterogeneous Pd–catalyst
system (Pd-MNPSS) was
developed using immobilization of Pd species (Pd<sup>II</sup> and
Pd<sup>0</sup>) on starch-functionalized magnetic nanoparticles. For
the synthesis of Pd-MNPSS catalyst, first, magnetic nanoparticles
(MNPs) were prepared and coated with a silica layer (Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>) to increase their stability and functionalization
capability. The Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub> particles
were reacted with thionyl chloride (SOCl<sub>2</sub>) to generate
chlorosilyl groups on the surface of MNPs. Reaction of starch with
chloro-functionalized MNPs leads to a magnetic reusable poly-hydroxy-functionalized
substrate (MNPSS), which is highly suitable for immobilization of
Pd metal on its surface. This catalyst system was designed to be applied
in Pd-catalyzed organic coupling reactions in water. Finally, the
Pd-MNPSS catalyst was prepared via reaction of MNPSS and PdÂ(OAc)<sub>2</sub>. After characterization of the Pd-MNPSS catalyst it was applied
in the Heck and Sonogashira coupling reactions in water solvent, and
excellent results were obtained. The catalyst system was separated
from the reaction mixture employing an outside magnetic field. In
these processes the catalyst was reusable for 5 times without remarkable
decrease in its activity. The Pd-MNPSS catalyst has many advantages
especially in the workup process related to our previously reported
catalyst systems, Pd supported on silica–starch substrate (PNP-SSS)
and Pd supported on silica–cyclodextrin substrate (PNP-SCD)
Carbohydrates as a reagent in multicomponent reactions: one-pot access to a new library of hydrophilic substituted pyrimidine-fused heterocycles
Synthesis and characterization of diethyl-dithiocarbamic acid 2-[4-(2-diethylthiocarbamoylsulfanyl-2-phenyl-acetyl)-2,5-dioxo-piperazin-1-yl]-2-oxo-1-phenyl-ethyl ester as new reversible addition-fragmentation chain transfer agent for polymerization of ethyl methacrylate
ChemInform Abstract: One-Pot Synthesis of N-Alkyl Purine and Pyrimidine Derivatives from Alcohols Using TsIm: A Rapid Entry into Carboacyclic Nucleoside Synthesis.
A convenient and efficient one-pot N-alkylation of nucleobases from alcohols using
N-(
p-toluenesulfonyl)imidazole (TsIm) is described. In this method, treatment of alcohols with a mixture of purine or pyrimidine nucleobase, TsIm, K
2CO
3, and triethylamine in refluxing DMF regioselectively furnishes the corresponding
N-alkyl nucleobases in good yields. This methodology is highly efficient for various structurally diverse primary alcohols.
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