Ruthenium(Ⅲ) chloride as an efficient catalyst for the synthesis of perimidine derivatives under mild conditions

Various biologically important perimidine derivatives have been synthesized efficiently from various ketones and naphthalene1,8-diamine by using a catalytic amount of RuC13 (1 mol%). This method is a very simple and high yielding reaction for the synthesis of perimidine derivatives.     

Wet carbon-based solid acid/potassium permanganate as an efficient heterogeneous reagents for oxidation of alcohols under mild conditions

Wet carbon-based solid acid and potassium permanganate were used as new reagents for oxidation of alcohols to their corresponding aldehydes and ketones in heterogeneous mixtures. The experiments were done moderately at mild condition and high yields in suitable times were obtained.     

Zeolite nanoparticles (H-ZSM5) as a highly efficient,green, and reusable heterogeneous catalyst for selective oxidation of sulfides to sulfoxides under mild conditions

H-ZSM5 is applied as an efficient, highly reusable, and heterogeneous catalyst for the oxidation of sulfides to sulfoxides using 30% H₂O₂ under solvent-free conditions at room temperature. A variety of aromatic and aliphatic sulfides with different functional groups were successfully oxidized with good to excellent yields in short reaction times. The catalyst can be easily recovered by simple filtration and recycled for several consecutive runs without any significant loss of its catalytic activity.     

Silica-bonded N-propyl sulfamic acid as an efficient recyclable catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones/thiones under heterogeneous conditions

Silica-bonded N-propyl sulfamic acid(SBNPSA) catalyzed one-pot three component Biginelli condensation of different substituted aromatic aldehydes with ethyl acetoacetate and urea/thoiurea to the respective 3,4-dihydropyrimidin-2-(1H)-ones and thiones in environment friendly procedure is described. The facile reaction conditions, simple isolation and purification procedures of this method make it a good option for the synthesis of dihydropyrimidinones.     

ZrOCl2·8H2O as an efficient and recyclable catalyst for the clean synthesis of xanthenedione derivatives under solvent-free conditions

ZrOCl₂·8H₂O was found to be an efficient and recyclable catalyst for the reaction of aromatic aldehydes with dimedone to afford 1,8-dioxo-1,2,3,4,5,6,7,8-octahydroxanthenes under solvent-free conditions. Short reaction time, excellent yields and simple work-up are the advantages of this procedure. The interaction obtained from XRD studies was shown that the catalyst loses H₂O during the reaction but it did not affect catalytic activity of the catalyst and the catalyst could be reused several times.     

Palladium supported on metal–organic framework as a catalyst for the hydrogenation of nitroarenes under mild conditions

Sustainable development demands an environmentally friendly and efficient method for the hydrogenation of organic molecules, including the hydrogenation of functionalized nitroarenes. In this study, a highly active and selective metal–organic framework-supported palladium catalyst was prepared for the catalytic hydrogenation of nitroarenes. High selectivity (>99%) and excellent yield (98%) of aniline were realized after 2 hours in ethanol under hydrogen (1 atm) at room temperature. The reductions were successfully carried out in the presence of a wide range of other reducible functional groups. More importantly, the catalyst was very stable without the loss of its catalytic activity after five cycles.     

Poly(ethylene glycol)–bound sulfonyl chloride as an efficient catalyst for transformation of aldoximes to nitriles

An operationally simple, efficient, and environmentally benign preparation of nitriles in good to excellent yields from various aldoximes in the presence of recyclable poly(ethylene glycol)–bound sulfonyl chloride is described.     

Nano TiO_2 as a heterogeneous catalyst in an efficient one-pot three-component Mannich synthesis of β-aminocarbonyls

TiO₂ nanoparticles（TiO₂ NPs） worked as an efficient heterogeneous catalyst in a one-pot,three-component,and solvent free Mannich reaction;producing variousβ-aminocarbonyls in good yields,and with good stereoselectivities.The catalyst was easily separated from the reaction mixture and was recycled four times with no significant loss of its catalytic activity.     

Tris(hydroxymethyl)aminomethane as an efficient organobase catalyst for the synthesis of β-phosphonomalonates

Tris(hydroxymethyl)aminomethane (THAM) is a highly efficient and recyclable organobase catalyst for the nucleophilic phosphonylation of benzylidene malononitrile under solvent-free conditions. This new catalytic methodology is applicable without a solvent, eco-friendly, economically viable, avoids conventional isolation procedures, and has a facile work-up procedure and wide scope. THAM is an inexpensive, commercially available, non-toxic, and biodegradable novel organocatalyst. Furthermore, it can be reused in up to five cycles without loss in catalytic activity, and no chromatographic separation is needed to obtain the desired products.     

Cu(CH3CN)4PF6 immobilized on halloysite as efficient heterogeneous catalyst for oxidation of allylic C–H bonds in olefins under mild reaction condition

Research on Chemical Intermediates - Considering the importance of oxidation of allylic C–H bonds in olefins and the unresolved challenging issues, such as long reaction time and the large...     

Covalently anchored sulfonic acid on silica gel （SiO2-R-SO3H） as an efficient and reusable heterogeneous catalyst for the one-pot synthesis of 1,8-dioxooctahydroxanthenes under solvent-free conditions

A highly efficient one-pot synthesis of 1,8-dioxooctahydroxanthenes under solvent-free conditions catalyzed by sulfonic acid covalently anchored onto the surface of silica gel is reported.All types of aldehydes,including aromatic,unsaturated,and heterocyclic,are used.The silica gel/sulfonic acid catalyst (SiO2-R-SO3H) is completely heterogeneous and can be recycled.     

A sulfonate-based Cu(Ⅰ) metal-organic framework as a highly efficient and reusable catalyst for the synthesis of propargylamines under solvent-free conditions

A new highly efficient and reusable Cu(Ⅰ)-MOF has been developed for the synthesis of propargylamine compounds via the three-component reaction of secondary amines,alkynes.and aromatic aldehydes under solvent-free conditions.The desired propargylamines were obtained in good to excellent yields with a low catalyst loading.The catalyst may be recovered and reused for up to 5 cycles without major loss of activity.This protocol has the advantages of excellent yields,low catalyst loading,and catalyst recyclability.     

Synthesis of 1,8-dioxooctahydroxanthenes utilizing PMA-SiO_2 as an efficient reusable catalyst

PMA-SiO2 has been utilized as an efficient catalyst system in preparation of 1,8-dioxooctahydroxanthenes.     

Cu(OAc)2 entrapped on ethylene glycol-modified melamine–formaldehyde polymer as an efficient heterogeneous catalyst for Suzuki–Miyaura coupling reactions

Research on Chemical Intermediates - This work is described as an environmental friendly approach for Cu(OAc)2 entrapped on ethylene glycol-modified melamine–formaldehyde-based polymeric...     

Salen–Mg-doped NH2–MIL-101(Cr) for effective CO2 adsorption under ambient conditions

A novel metal-doped metal–organic framework (MOF) was developed by incorporating salen–Mg into NH₂–MIL-101(Cr) structure under ambient conditions. The Schiff base complex was successfully prepared by condensing salicylaldehyde with a free amino group and then coordinating metal ions. Such a structure can endow the sample with higher CO₂ adsorption performance. At 0°C and 1 bar, the salen–Mg-modified sample achieves the maximum adsorption capacity of 2.18 mmol g⁻¹ for CO₂, which was 5.8% higher than the pristine salen–MOF under the same conditions. Notably, the Freundlich model indicates that the CO₂ adsorption process of all samples conforms to reversible adsorption. However, the correlation coefficients (R²) of the Mg-doped sample are lower than that of the pristine sample. Besides, the CO₂/N₂ adsorption selectivity and isosteric heat also show a similar trend. These results indicate that the salen–Mg can enhance the interaction between the material and CO₂ molecules.     

NiSO4·6H2O as a new,efficient, and reusable catalyst for the α-aminophosphonates synthesis under mild and eco-friendly conditions

Research on Chemical Intermediates - Nickel (II) sulfate hexahydrate is used for the first time as an efficient catalyst for the one-pot synthesis of α-aminophosphonates by three-component...     

Manganese(II) salts as efficient catalysts for chemo selective transesterification of β-keto esters under non-conventional conditions

Transesterification of β-ketoesters with various alcohols has been studied under conventional and non-conventional conditions using desktop chemicals such as Mn(II) salts as catalysts. These methods offered transesterification of β-ketoesters in good yields with dramatic rate accelerations and reduced reaction times. The developed protocols under nonconventional methods such as sonication and microwave irradiation are highly promising compared with the existing procedures.     

Iodine as a mild and efficient catalyst for the diastereoselective synthesis of δ-silyloxy-γ-lactones

Aldehydes undergo smooth nucleophilic addition with 2-trimethylsilyloxyfuran in the presence of 10 mol % of iodine under mild and neutral conditions to produce the corresponding δ-silyloxy-α,β-unsaturated-γ-lactones in high yields and with moderate diastereoselectivity. ortho-Substituted benzaldehydes afford the syn-isomer predominantly. The use of iodine makes this procedure quite simple, more convenient and cost-effective.     

Synthesis of bioactive heterocycles using reusable heterogeneous catalyst HClO4–SiO2 under solvent-free conditions

We are reporting a simple, efficient and green protocol for the synthesis of chromenes and dihydropyrimidines (products of Knoevenagel and Biginelli reaction, respectively) by the use of silica-supported perchloric acid (HClO₄–SiO₂) as an effective heterogeneous catalyst. Short reaction times, high product yields, simple procedure and reusability of the catalyst are the superior characteristics of this protocol.