A new uncapped SnO2 quantum dots (QDs) catalyzed strategy for the synthesis of substituted pyrano[2,3-c]pyrazole and spiro-2-oxindole derivatives has been developed via a multicomponent one pot approach in aqueous medium. The reactions can be performed at low catalyst loadings with excellent functional group tolerance. This communication also reports a comparative study of the efficiency related to the catalytic activity of uncapped SnO2 QDs, oleic acid capped SnO2 QDs, and SnO2 nanoflower. Uncapped SnO2 QDs, capped SnO2 QDs, and SnO2 nanoflower were prepared by simple solvothermal method and characterized by XRD, FESEM, and TEM images. The easy recovery of the catalyst and high yield of the products make the protocol attractive, sustainable, and economic. The catalyst was reused for six cycles with almost unaltered catalytic activity. © 2014 Elsevier Ltd.

ASISH DAS

Chemistry

S PAUL

K PRADHAN

S GHOSH

S K DE

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Tetrahedron

A tin oxide (SnO2) quantum dot (QD) catalyzed approach for the synthesis of indeno and acenaphtho cores containing dihydroxy indolone, pyrrole, coumarin and uracil fused derivatives was achieved via a multicomponent one-pot approach in aqueous medium. A variety of functional groups were compatible with the reaction conditions. This synthesis was established to follow the group-assistant-purification chemistry process, thus avoiding the use of traditional chromatography. An SnO2 QD was prepared using a simple solvothermal method and characterized using X-ray diffraction and transmission electron spectroscopy images. The easy recovery of the catalyst and high yield of the products make the protocol attractive, sustainable and economic. The catalyst was reused for seven cycles with almost unaltered catalytic activity. The low cost, ease of handling and the simplicity of this catalytic system make the method competitive with other strong mineral acid-catalysed multicomponent protocols. © The Royal Society of Chemistry 2015.

RSC Advances

Synthesis of indeno and acenaphtho cores containing dihydroxy indolone, pyrrole, coumarin and uracil fused heterocyclic motifs under sustainable conditions exploring the catalytic role of the SnO2 quantum dot

CuFe2O4 magnetic nanoparticles were synthesized and recognized as an efficient catalyst for the one-pot synthesis of dihydropyrano[2,3-c]pyrazole, pyrano[3,2-c]coumarin and 4H-chromene derivatives at mild conditions and in excellent yields. The four component reaction (4CRs) of a wide variety of substituted hydrazine derivatives, ethyl acetoacetate, dialkyl acetylenedicarboxylates and alkyl nitrile derivatives (malononitrile and ethyl cyanoacetate) gave the targeted dihydropyrano[2,3-c]pyrazoles. When two equivalents of dialkyl acetylenedicarboxylates were introduced replacing ethyl acetoacetate, a new four-component reaction took place providing another type of dihydropyrano[2,3-c]pyrazole derivatives. An efficient and practical route to pyrano[3,2-c]coumarin and 4H-chromene framework has also been developed by one-pot, three-component reaction (3CRs) of 4-hydroxycoumarin/dimedone/ cyclohexane-1,3-dione, dialkyl acetylenedicarboxylates and alkyl nitriles. CuFe2O4 magnetic nanoparticles were prepared by a simple and effective citric acid complex method and characterized by using XRD, FT-IR, EDX and TEM image. The catalyst was recycled for six cycles with almost unaltered catalytic activity. All reactions were easily performed and proceeded with high efficiency under very simple and mild conditions and gave excellent yields avoiding time-consuming, costly syntheses, and tedious workup and purification of products. © 2014 The Royal Society of Chemistry.

Catalysis Science and Technology

Magnetically retrievable nano crystalline CuFe2O4 catalyzed multi-component reaction: A facile and efficient synthesis of functionalized dihydropyrano[2,3-c]pyrazole, pyrano[3,2-c]coumarin and 4H-chromene derivatives in aqueous media

An efficient and green protocol for the synthesis of dihydropyrano[2,3-c] chromene derivatives by one-pot, three component coupling reaction of aromatic aldehyde, malononitrile, and 3-hydroxycoumarin has been developed using nano-structured ZnO as the catalyst. The formation of self-assembled organic nanofiber arising from low-molecular-weight molecules has also been performed. The optical properties of the nano-structured organic molecules were studied. © 2011 Elsevier Ltd. All rights reserved.

Tetrahedron Letters

One-pot synthesis of dihydropyrano[2,3-c]chromenes via a three component coupling of aromatic aldehydes, malononitrile, and 3-hydroxycoumarin catalyzed by nano-structured ZnO in water: A green protocol

Dalton Trans.

Effect of oleic acidligand on photophysical, photoconductive and magnetic properties of monodisperse SnO2quantum dots

Chemical Communications

Microwave assisted fast and facile synthesis of SnO2 quantum dots and their printing applications

The Journal of Physical Chemistry C

Synthesis, Characterization, and Photocatalytic Activity of Zn-Doped SnO2 Hierarchical Architectures Assembled by Nanocones

Uncapped SnO2 quantum dot catalyzed cascade assembling of four components: A rapid and green approach to the pyrano[2,3-c]pyrazole and spiro-2-oxindole derivatives

Journal	Data powered by TypesetTetrahedron
Publisher	Data powered by TypesetElsevier Ltd
ISSN	0040-4020
Open Access	No