The halogen-free Brnsted acidic ionic liquid methylimidazolium hydrogen sulfate ([Hmim] + HSO 4 -) acts as a very efficient catalyst for the one-pot, two-component Baeyer condensation of a variety of aromatic aldehydes with dimethyl or diethyl aniline at room temperature. This green reagent behaves as both catalyst and solvent; that is, it exhibits dual-reagent catalysis. The room-temperature acidic ionic liquid could be recycled several times with almost no loss in the yield of the reaction. This is the first report of the Baeyer synthesis with a halogen-free ionic liquid. © 2012 Taylor and Francis Group, LLC.

CHHANDA MUKHOPADHYAY

Chemistry

A DATTA

P K TAPASWI

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.

&nbsp;

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.

&nbsp;

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

Halogen-Free Room-Temperature Brønsted Acidic Ionic Liquid [Hmim]+ HSO4 − as a Recyclable Green “Dual Reagent” Catalysis for the Synthesis of Triarylmethanes (TRAMs)

Synthetic Communications

This is the first report of thiol-induced, recyclable ZnO–[2COOHMIM]+Br−-catalysed (2COOHMIM=1-(2-carboxyethyl)-3-methylimidazolium), water-mediated 2-pyridone synthesis by two new straightforward strategies with 37 examples. This catalytic system was prepared using environmentally friendly, recyclable acidic-ionic-liquid-coated ZnO nanoparticles (NPs). The changes in size and morphology upon capping the ZnO NPs were effectively tuned by neutral and acidic ionic liquids, which acted as structure-directing mediators. ZnO has a high affinity for carboxyl functionalities, and accordingly, a 3D network was formed in which the carboxyl group acted as a linker. The catalysts generated by the capping of ZnO NPs with ionic liquids were characterised by scanning electron microscopy, transmission electron microscopy, dynamic light scattering, powder X-ray diffraction, and FTIR spectroscopy. This combined catalytic system, containing both acidic and basic environments, exhibited properties of both a quasi-heterogeneous catalyst and a phase-transfer catalyst in aqueous medium. Here, a synergistic catalytic effect between ZnO NPs and acidic ionic liquids is utilised effectively. The recyclability of this catalytic system up to a fifth cycle was demonstrated by FTIR spectroscopy. © 2018 Wiley-VCH Verlag GmbH &amp; Co. KGaA, Weinheim

Asian Journal of Organic Chemistry

Fabrication of Ionic-Liquid-Embedded ZnO Nanoparticles: Application of a Synergistic Catalytic Effect to Thiol-Induced 2-Pyridone Synthesis

Bulletin of the Moskow State Regional University

10.18384/2224-0209-2013-3

Macromolecular Rapid Communications

Macromol. Rapid Commun. 14/2010

ChemInform

ChemInform Abstract: Montmorillonite K10 Clay Catalyzed Baeyer Condensation of Heterocyclic Aldehydes with N,N-Dimethylaniline: Synthesis and Photoirradiation Studies of Heteroaryldiarylmethanes.

Efficient and Green Synthesis of 1,2-Disubstituted Benzimidazoles and Quinoxalines Using Br⊘nsted Acid Ionic Liquid, [(CH2)4SO3HMIM][HSO4], in Water at Room Temperature

Journal of the Society of Dyers and Colourists

Steric and Electronic Effects in Basic Dyes VI - Electronic Absorption Spectra of Derivatives of Brilliant Green Containing Substituents in the Phenyl Ring

Halogen-free room-temperature brÃ¸nsted acidic ionic liquid [Hmim] + HSO 4 - as a recyclable green "dual reagent" catalysis for the synthesis of triarylmethanes (TRAM s) ;

Journal	Synthetic Communications
Publisher	-
ISSN	0039-7911
Open Access	No