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; Fe₃O₄@SiO₂@PPh₂) as a magnetic recyclable phosphorus ligand in the presence of Ru₂Cl₄(CO)₆ 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

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-101­(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-101­(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^II and Pd⁰) on starch-functionalized magnetic nanoparticles. For the synthesis of Pd-MNPSS catalyst, first, magnetic nanoparticles (MNPs) were prepared and coated with a silica layer (Fe₃O₄@SiO₂) to increase their stability and functionalization capability. The Fe₃O₄@SiO₂ particles were reacted with thionyl chloride (SOCl₂) 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 Pd­(OAc)₂. 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)

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. [Display omitted