Arti Jain

Magnetic nanoparticles catalyzed synthesis of diverse N -Heterocycles

A large library of diversified compounds (pyrano [2,3-d]pyrimidines, pyrido[2,3-d] pyrimidines and a variety of spirooxindoles) were synthesized through a very efficient, economical and environmentally benign process utilizing magnetic nanoparticles. Ease of recovery using an external magnetic field is an additional ecofriendly attribute of this catalytic system. Most of the compounds are new; therefore, could be further explored for their pharmaceutical application. Moreover, column chromatography and recrystallisation of the products is not required as the crude products are already highly pure and hence can be used for target oriented synthesis on a wide scale.

Efficient entry to diversely functionalized spirooxindoles from isatin and their biological activity

A collection of structurally complex and chemically diverse small molecules is a useful tool to explore cell circuitry. In this article, we have reported the two step synthesis of diverse spirooxindoles. The key reaction to assemble the spirooxindole core is a Lewis acid catalyzed three component coupling. The final library of compounds was then analyzed for their cytotoxic activity against U87 human glioma cells. It is noteworthy to mention that this is the first report on the pharmaceutical evaluation of such compounds. Although the activity is moderate, it opens the door for new chemical modifications of spirooxindoles.Graphical abstract

Application of mobilized Cu-nanoparticles as heterogeneous catalyst for the synthesis of α-amino phosphonatesviaA2-P coupling

Cu-nanoparticles were synthesized and utilized as an efficient, novel and recyclable catalyst for a multi-component coupling reaction using aldehyde, amine and diethyl phosphite. This method provides a wide range of substrate applicability and devoid of co-catalyst/heavy metals with an excellent yield of bioactive α-amino phosphonates. Besides this, catalyst could be recovered and reused up to four runs with almost consistent activity.

Laccase—a natural source for the synthesis of benzofuro[2,3-c]pyrazolin-5-ones

Enzymatic oxidation of catechols/hydroquinones in the presence of pyrazolin-5-ones as a nucleophile in aqueous solution has been investigated in detail by applying laccase as a catalyst. This is the first report for the enzymatic synthesis of a novel series of compounds. We derived some new compounds with the catechol/hydroquinone ring in moderate yields based on enzymatic synthesis in an environmentally benign aqueous solution. These types of reactions represent a milestone along the path of future sustainable green chemistry.

Ecofriendly approach for detection of phenols in water using laccase from different fungi.

Laccase-initiated oxidative coupling reactions of phenol and its derivatives with 4-aminoantipyrene using air as an oxidant has been investigated. The oxidation reaction of phenols and 4-aminoantipyrene is getting a lot of attention due to environmental concerns. Oxidation of simple phenol and 4-aminoantipyrene as a benchmark reaction enabled us to rank the relative oxidation ability of various laccases. Among the laccases tested, laccase from Pycnoporus cinnabarinus successfully yielded 72% antipyrilquinoneimine dye. The present method can also be used to determine p-substituted phenols and chlorophenols. In this work, the influence of mediators on laccase activity has also been studied.

Bis[(l)prolinate-N,O]Zn: A water-soluble and recycle catalyst for various organic transformations

Graphical abstract

A green oxidation protocol for the conversion of secondary alcohols into ketones using heterogeneous nanocrystalline titanium (IV) oxide in polyethylene glycol

Abstract The oxidation of secondary alcohols into corresponding ketones has been described using heterogeneous nanocrystalline TiO2 as catalyst at a moderate temperature with quantitative yields. Use of H2O2 instead of O2 (g) is the main feature of our methodology since maintenance of PO2 (g) at elevated temperature is not easy. Besides, this catalyst could be recovered and reused for further reactions with consistent activity. Hence, our present protocol is economical and throughout clean consisting of green reagent, solvent, and catalyst.

Porous Silica Nanoparticles from Rice Husk for the Elimination of Erichrome Black T (EBT) from Laboratory Waste Water

Water effluents of various chemical laboratories are expected to consist of wide range of organic waste products whose removal is an arduous task and a serious concern with the objective of eradication of all the pollutants from laboratory waste water has been attempted to modify rice husk’s surface. The efficacy of the designed adsorbent derived using rice husk and its potential in removing the residual dyes has been evaluated in this research. Both raw silica and functionalized silica obtained from the rice husk have proved to possess greater ability than activated charcoal for the biosorption of dyes present in contaminated water. A comparative account of silica, functionalized silica and activated charcoal acting as biosorbent for a common acidic dye: EBT was studied using FT-IR, TEM, IR spectroscopy techniques for their characterization. It was also observed that adsorption tendency of adsorbent was governed by experimental condition directly. The variation in rates and thermodynamic factor also influences the adsorption efficiency. For the removal of EBT from waste water functionalized silica was revealed to be most efficient.

Use of Cost Effective Kitchen Ingredients in Acid-Base Titrations: A Greener Approach

The volumetric analysis allows the quantitative chemical analysis of a solution of the unknown concentration (acid/base) by titrating it with the solution of accurately known concentration (base/acid). For this purpose, chemicals indicators such as phenolphthalein, methyl orange, methyl red, congo red etc. are used. These indicators are expensive and some of them have toxic effects on users and can also cause environmental pollution. Therefore, an attempt has been made to investigate the indicator activity of some of the fruits, vegetables and kitchen spices. The current paper recommends the use of natural indicators such as Curcuma longa (turmeric), Beta vulgaris (beetroot), Citrus × limon (lemon), Citrus reticulata (orange), Citrus limetta (sweet lime), Solanum lycopersicum (tomato), etc. as a strategy for environment remediation, to reduce toxicity and to decrease the respective cost of the synthetic indicators. Various acid-base titrations were carried to ensure a sharp color change with respect to the pH of the medium. The promising results were obtained using comparative studies against standard synthetic indicators. Consequently, the authors suggest that these indicators can be used as pH indicators in the college laboratories for undergraduate courses.