For the first time, we have used activated alumina balls (3-5 mm diameter) for amide synthesis from carboxylic acids (unactivated) and amines (unactivated) under neat reaction conditions that produce no toxic by-products and has the advantages of being low-cost, easily available, heterogeneous, reusable and environmentally benign with no troublesome/hazardous disposal of the catalyst. © 2012 The Royal Society of Chemistry.

SUMITA BANDYOPADHYAY

Bio-Physics, Molecular Biology and Bioinformatics

CHHANDA MUKHOPADHYAY

Chemistry

S GHOSH

A BHAUMIK

J MONDAL

A MALLIK

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

Green Chemistry

We report a green, efficient and straightforward approach for the regioselective synthesis of new spiro-heterocyclic scaffolds using environmentally benevolent activated alumina balls (3-5 mm diameter) as a catalyst under neat reaction conditions. The methodology is advantageous because of its short reaction time, moderate to excellent yields, easy work-up, practical simplicity and high regioselectivity without any troublesome/hazardous disposal of the catalyst or toxic byproducts. The pore size of the catalyst plays a key role in the formation of the spiro derivatives. Specifically, we observed that the reaction yield was hardly affected by the surface area or pore volume, but surprisingly, the yield correlated directly with the pore size of the catalyst. © 2016 Wiley-VCH Verlag GmbH &amp; Co. KGaA, Weinheim.

ChemCatChem

Activated Alumina Balls under Neat Conditions: A Green Catalyst for the Synthesis of Spiro-Heterocyclic Scaffolds by Ring-Opening versus Annulation of the Isatin Moiety

European Journal of Organic Chemistry

The Uncatalyzed Direct Amide Formation Reaction - Mechanism Studies and the Key Role of Carboxylic Acid H-Bonding

Organic Letters

Cross-Coupling of Mesylated Phenol Derivatives with Potassium Ammonio- and Amidomethyltrifluoroborates

Synthesis

The Thermal Amidation of Carboxylic Acids Revisited

Chemical Communications

Clean, reusable and low cost heterogeneous catalyst for amide synthesis

Schweizer Archiv für Tierheilkunde

Gallengangskarzinom bei einer Kuh

Direct amide bond formation from carboxylic acids and amines using activated alumina balls as a new, convenient, clean, reusable and low cost heterogeneous catalyst

Journal	Green Chemistry
Publisher	ROYAL SOC CHEMISTRY
ISSN	1463-9262
Open Access	No