Preyas Ankit

Nucleophilic heterocyclic carbene promoted one pot multicomponent synthesis of new 6-(1H-indol-3-yl)-2-oxo-4-aryl-1,2,3,4 tetrahydropyrimidine-5-carbonitriles: an eco-compatible approach with PEG as a biodegradable medium

A three-component, one-pot, simple, direct and highly efficient cyclocondensation method has been developed for the synthesis of fourteen 6-(1H-indol-3-yl)-2-oxo-4-aryl-1,2,3,4-tetrahydropyrimidine-5-carbonitriles by combining an arylaldehyde with 3-(cyanoacetyl)-indoles and urea in the presence of the PEG-400 and a catalytic amount of the thiazolium anion. A short reaction time, simple reaction conditions, ease of product isolation, use of a cheap and readily available and reusable catalyst make this method very attractive from an environmental and economic perspective.

Development of five membered heterocyclic frameworks via [3+2] cycloaddition reaction in an aqueous micellar system

A series of novel dihydropyrrolo[2,1-a]isoquinolines and dihydropyrrolo[1,2-a]quinolines have been synthesized from isoquinolines/quinolines, various substituted phenacyl bromides and substituted dialkylacetylenedicarboxylates via [3+2] cycloaddition reaction. The reaction proceeds in aqueous micellar medium with DBU as a catalyst. The present protocol offers a simple one pot sequential reaction affording products in excellent yields.

Nucleophilic, Heterocyclic, Carbene-Catalyzed, Solvent-Free, One-Pot Synthesis of Polyhydroquinolines via Multicomponent Hantzsch Reaction: An Efficient and Ecofriendly Approach

Abstract A simple, efficient, and ecofriendly one-pot method has been reported for the synthesis of polyhydroquinolines in excellent yield using nucleophilic heterocyclic carbene as catalyst. The generalized approach is the Hantzsch four-component reaction of aromatic aldehyde, ethyl acetoacetate, cyclic 1,3-diketone, and ammonium acetate. GRAPHICAL ABSTRACT

Supramolecular catalysis in the synthesis of polyfunctionalised pyrroles

An efficient sequential one pot three component reaction involving anilines, DEAD/DMAD and glyoxal in aqueous media is reported. The protocol is environmentally benign and provides a new synthetic route to access polyfunctionalised pyrrole derivatives in high yield. The reaction proceeded via supramolecular catalysis.

Microwave-Induced Solvent-Free Synthesis and Antifungal Screening of Novel Spiro Heterocyclic Systems Containing 3,5-Diphenyl-7H-thiazolo[3,2-a]pyrimidine and Indolin-2-one

Abstract A microwave-induced technique has been developed for the synthesis of a series of novel spiro indoline-based heterocycles (7a–g) at atmospheric pressure in an open vessel using an environmentally benign procedure. This rapid method produces pure products in good yields within a few minutes in comparison to the conventional procedure developed for the synthesis of these heterocycles. The synthesized compounds have been screened in vitro for antifungal activity against two fungal strains (i.e., Aspergillus niger and Aspergillus flavus). All compounds have shown significant activity against these pathogens. [Supplementary materials are available for this article. Go to the publishers online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.] GRAPHICAL ABSTRACT

Surface Enhanced Raman Spectroscopy of Volatile Organic molecules on the surface of Zinc Nanoparticles Produced by Laser Ablation

Surface enhanced Raman spectroscopy have provided potential tool for the detection of organic/biological molecules within the cell of living organism. This technique is suitable for in vivo as well as in vitro detection upto single molecular level. In the present work we have studied SERS activity of zinc nanoparticles on CCl4 and CHCl3 molecules. Colloidal solution of zinc nanoparticles was found as a suitable substrate for Raman signal enhancement. The applied technique may be useful for the sensing of organic/biological molecules as a trace in solid as well as in liquid media.

Triphenylphosphine-Catalyzed, Novel, One-Pot, Multicomponent Synthesis of Functionalized β-Acetamido Carbonyls

Abstract An efficient triphenylphosphine-catalyzed synthesis of β-acetamido carbonyls via multicomponent reaction of aromatic aldehydes, enolizable ketones or β-keto esters, acid chlorides and acetonitrile at room temperature is described. The process is remarkably simple, environmentally benign, and uses Lewis base for the first time in such type of reaction. GRAPHICAL ABSTRACT

Novel, versatile and eco-compatible preparation of new 6-(1 H -indol-3-yl)-2-oxo-4-aryl-1,2,3,4-tetrahydropyrimidine-5-carbonitriles in water

A three-component, one-pot, simple and direct, highly efficient cyclocondensation method has been developed for the synthesis of 11 6-(1H-indol-3-yl)-2-oxo-4-aryl-1,2,3,4-tetrahydropyrimidine-5-carbonitriles by combining an araldehyde with 3-(cyanoacetyl)-indole and urea in the presence of the cationic surfactant, CTAB and a catalytic amount of thiamine hydrochloride in water. A short reaction time, simple reaction conditions, ease of product isolation, and use of a cheap and readily available reusable catalyst make this method very attractive from an environmental and economic perspective.

In situ activation of Mn in semiconductor quantum dots in the presence of a biopolymer matrix

We report the synthesis and characterization of zinc sulphide quantum dots (QDs) in the presence of Mn2+ and a chitosan environment, which results in the formation of novel chitosan–zinc oxide QD nanocomposites containing Mn2+ in traces. The location of Mn2+ in these composites has been especially considered. The optical properties revealed that, instead of doping, activation by Mn2+ occurs at the interface of the zinc sulphide–chitosan matrix.

Raman Signal Enhancement Based Chemical Sensing of Volatile Organic Compounds

Surface enhanced Raman scattering based optical sensing (SERS‐OS) is one of the most powerful techniques for the sensitive and selective detection of low concentration analytes. Mostly, metallic nanoparticles, such as Ag, Au and Cu, are used as substrate materials in this technique. Present work is concerned with the possibility of utilization of colloidal zinc nanoparticles, produced by pulsed laser ablation method, as substrate material in SERS‐OS.