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Background: Poly ethylene glycol based dicationic acidic ionic liquid catalysts [PEG-DAIL, Cl] have been prepared by mono chloroacetic acid and used as a cost effective alternative to [PEG1000DAIL, HSO3], a sultone based catalyst. Biginelli reaction is found in a large family of biologically active molecules exhibiting a wide range of important pharmacological properties. Synthesis of 3,4-dihydropyrimidin-2(1H)-ones has been already reported using wide variety of acid catalysts. Method: Three materials were prepared using different molecular weights of PEG. These catalysts are termed as (i) [PEG600-DAIL, Cl] (ii) [PEG1500-DAIL][Cl] and (iii) [PEG4000-DAIL, Cl]. The synthesized material [PEG-DAIL, Cl] were characterized by FT-IR, 1H-NMR, 13C-NMR, ESI-MS, DSC and TGA techniques. The products were further confirmed by the GC-MS and NMR techniques. Results: Synthesized material is acidic in nature, which is proved by pH studies. These materials have good thermal stability and wide range of solubility in different solvents. These catalysts explored for test reaction as Biginelli reaction for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones as a acid catalyst under mild reaction conditions. Conclusion: The present method provides yet another series of catalysts for the Biginelli reaction. On comparison of initial rate mmol.min-1 and acidity of the catalyst for the said reaction, [PEG1500-DAIL][Cl] shows better results as compared to other two. The catalyst system was found that reusable up to five cycles without much loss in activity. Separation and reuse of this catalyst is simple and economical.

Background: There are various conventional ways for the synthesis of aromatic ketones but suffer from disadvantages like the use of toxic reagents, stoichiometric reagents producing huge amount of byproducts, thus causing hazard to the environment, whereas homogeneous protocols or the noble metal which support catalytic processes are not economically viable. On this ground, an effort was made to develop new green catalytic protocol to overcome these environmental concerns. The catalytic activity of manganese dioxides prepared by different recipes was investigated for the oxidation of allylic and benzylic alcohols. Methods: MnO2 B sample was prepared by calcinations of manganese nitrate while sample ANMnO2 was prepared by the reduction of potassium permanganate using triethanolamine as a reductant. All the samples were well characterized by XRD, SEM, EDX and TEM techniques. All the prepared catalyst samples along with commercial MnO2 were tested for the oxidation of alcohols using TBHP as a clean oxidant, where % conversion and % selectivity were determined by Gas Chromatography. The products were further confirmed by the GC-MS and NMR techniques. Results: Of all the oxides, nano amorphous manganese dioxide exhibited significant catalytic activity and selectivity for the corresponding carbonyls. Change from bulk to nano structure enhanced the catalytic activity because of its higher surface area and change in Mn3+/ Mn4+ ratio. The nano amorphous MnO2 (ANMnO2)/TBHP in acetonitrile solvent catalytic system was found to be most efficient with substrate compatibility. In mechanistic investigations, it was observed that from the bulk to the nano structure, Mn3+ species content in an oxide increased which may play a crucial role in the activity. It was also confirmed by hydrogen peroxide decomposition studies. The catalyst ANMnO2 was found to be reusable for five consecutive cycles with no significant loss in catalytic activity. Conclusion: In conclusion, change in the catalyst's preparation recipe not only alters the particle size but also affects the ratio of Mn3+ to Mn4+ species on the surface as well as on the bulk and thereby catalytic activity. On comparison of initial rate m-2g of all the catalyst samples for the said reaction, there was no significant difference observed which clearly proved the role of Mn3+ in catalytic activity.

Background: Nickel-Boron amorphous alloys (catalysts) of var- ious Ni:B ratio were synthesized and well characterized using XRD, ICP- AES, EDAX and IR spectroscopic technique. Among all the catalysts, Ni:B alloy catalyst with ratio 1:1 was found to effective for catalytic transfer hy- drogenation reaction using hydrazine hydrate as a proton donor. The present work shows the effect of metalloid content and the presence of aniline over CTH of nitrobenzene. The present catalytic protocol was found effective for wide variety of substrates showing its efficacy. Methods: A typical catalytic transfer hydrogenation reaction of nitroaro- matics using hydrazine hydrate was carried out in 2 necked, 25 ml round bottom flask in methanol. The progress of the reaction was monitored by the gas chromatog- raphy and products were further confirmed by GC-MS analysis. Nickel-Boron amorphous alloys (catalysts) were well characterized by XRD, SEM, EDX and ICP-AES analysis. Results: Among various compositions of Ni:B alloy catalysts, 1:1 ratio was found optimum for the CTH of nitrobenzene. It was observed that with increase in amount of nickel, catalytic activity for CTH decreases. Effect of aniline on reaction was evaluated by concentration ver- sus time plot. Considerable induction period was observed in absence of aniline not in case of other bases like NaOH, KOH, Na2CO3, etc confirming role of aniline in CTH reaction. From the Arrhenius plot for the CTH of nitrobenzene, the Ea was found to be 23.636 KJ mol-1. The catalytic protocol was found robust and effective for various substituted nitroaromat.ics Conclusion: Among various compositions obtained from ICP-AES analysis, the Ni:B alloy i.e. Ni62.71 B37.29 found to be the most efficient catalyst for the CTH of nitroaromatics over the other compositions. The catalyst found robust without changing its surface morphology after the reaction confirmed by SEM. Compared to reported catalytic system; this catalytic system is highly active and even worked with very low catalyst loading of 1 wt%. Apart from it we observed induction period for the said reaction and found that the presence of aniline hastens the rate of reaction. The system was widely applicable for the variety of substituted nitroaromatics which makes the system more interesting.

Synthesis of 1,4-dihydropyridines viaa four component one pot reaction starting from α,β-unsaturated aldehyde, β-keto ester, amine and alcohol, catalysed by SO42−/CexZr1−xO2is explored. The method has several advantages such as reusability of catalyst, avoidance of a multistep procedure and readily available starting materials. The protocol gives high to moderate yields for structurally diverse amines, β-keto esters and α,β-unsaturated aldehydes. SO42−/CexZr1−xO2(x= 0.02–0.15 mol%) catalysts were prepared and characterized by various analytical techniques such as XRD, FT-IR, TGA-DSC, SEM-EDAX and the total acidity.

A series of ALaNb2O7 (A=Cs, Rb, K) layered perovskites were synthesized by solid state method and characterized by XRD and acidity measurements. The catalytic activity of the synthesized perovskites was investigated for the aminolysis of epoxides and the acidity of these perovskites were correlated with their catalytic performance. Of the various perovskites studied, CsLaNb2O7 exhibited good catalytic activity and regioselectivity for the ring opening of epoxides. This is a first example of layered perovskite catalysed ring opening of epoxides that leads to good conversion of epoxides to β-amino alcohols under solvent-free conditions. The perovskite catalysts could be successfully reused with no significant loss in activity.

A simple and environmentally benign synthesis of 2-amino-4H-chromene is described using hydrotalcite as a solid base catalyst in aqueous medium. The catalysts were prepared by a co-precipitation method and well characterized by various techniques such as XRD, FT-IR, SEM and the basicity was found using the phenol adsorption method. The reusability of the catalyst, use of water as a green solvent and easy isolation of the product along with good yields make the present protocol sustainable and advantageous compared to conventional methods.

CeO2–ZrO2was explored as a bifunctional catalyst system for the synthesis of β-amino alcohols through epoxidation and subsequent aminolysis. Epoxidation of styrene to styrene oxide using t-butyl hydrogen peroxide (TBHP) as a green oxidant followed by subsequent aminolysis with diverse amines gave the corresponding β-amino alcohols. CeO2–ZrO2was found to be a reusable and highly selective catalyst for both the epoxidation and aminolysis reactions.

North East India is hot spots for several vector borne diseases such as malaria and Japanese Encephalitis. In spite of taking several well executed plans, the diseases continue to explode from time to time. Therefore, effective measures need to be planned to control mosquito breeding. We have synthesized C-dot@silver nanohybrids using fruits and vegetable wastes like orange peels, mango peels and Taro (Colocasia). The nanohybrids show its bio-larvicidal efficacy against mosquito vectors like Aedes albopictus, Anopheles stephensiand Culex quinquefasciatus.

The synthesis of N-tert-butylamides using SO42−/CexZr1−xO2catalysts under solvent-free conditions is reported. The methodology has several advantages such as reusability of the catalyst, solvent-free conditions, easy workup, and comparable yield of N-tert-butylamides. A variety of aliphatic, aromatic, and acid-sensitive substrates give high to moderate yields of the corresponding N-tert-butylamides. Surface acidities of the catalysts were correlated with the results obtained. To the best of our knowledge, this is the first report of a modified Ritter reaction on SO42−/CexZr1−xO2using tert-butyl acetate as carbocationic source.

Catalytic transfer hydrogenation (CTH) of aromatic nitro and carbonyl compounds over novel Fe(III) substituted hexagonal mesoporous aluminophosphate (FeHMA) molecular sieve catalyst showed excellent regioselectivity/chemoselectivity as well as superior recycling capability. Furthermore, the reduction occurs without affecting other functional groups such as –CN, –CHO, –Cl, –CH3, –OCH3and –NH2.

The used catalyst can be recycled and reactivated for up to six consecutive cycles.

Nano‐MgO/ZrO2is prepared and used as catalyst for cross‐aldol condensation, Cbz‐protection of amines, reduction of aromatic nitro compounds and the synthesis of 1,5‐benzodiazepines.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

For Abstract see ChemInform Abstract in Full Text.

For Abstract see ChemInform Abstract in Full Text.

For Abstract see ChemInform Abstract in Full Text.

For Abstract see ChemInform Abstract in Full Text.

For Abstract see ChemInform Abstract in Full Text.

For Abstract see ChemInform Abstract in Full Text.