Sharma, A and Kumar, R and Sharma, A and Kumar, Vinod and Sinha, Arun K (2008) Unique Versatility of Ionic Liquids as Clean Decarboxylation Catalyst Cum Solvent: A Metal- and Quinoline-Free Paradigm towards Synthesis of Indoles, Styrenes, Stilbenes and Arene Derivatives under Microwave Irradiation in Aqueous Conditions. Advanced Synthesis and Catalysis, 350 (18). pp. 2910-2920. ISSN 1615-4150

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Abstract

Ionic liquids have been found to provide a new platform for metal- and quinoline-free decarboxylation of various N-heteroaryl and aryl carboxylic acids under microwave irradiation in aqueous condition. The method was found to possess a wide substrate scope towards the synthesis of various pharmacologically and industrially important aromatic compounds including indoles, styrenes, stilbenes, and nitro- or hydroxyarene derivatives. The decarboxylation of indole and alpha-phenylcinnamic acids proceeded well without addition of any catalyst in neat 1-hexyl-3-methylimidazolium bromide ([hmim]Br) and 1-methylimidazolium p-toluenesulfonic acid ([Hmim]PTSA), respectively, while addition of a mild base like aqueous sodium hydrogen carbonate (NaHCO(3)) to [hmim]Br further improved the decarboxylation of hydroxylated cinnamic and aromatic acid substrates. The developed methodology not only precludes the usage of toxic metal/quinoline and harsh organic bases but also offers several inherent benefits like recyclability of reagent system, reduction in waste and hazards, short reaction time besides ease of product recovery.

Item Type:	Article
Uncontrolled Keywords:	carboxylic acids; decarboxylation; indoles; ionic liquids; microwave heating; styrenes
Subjects:	Synthetic Chemistry
Divisions:	UNSPECIFIED
Depositing User:	Dr. Aparna Maitra Pati
Date Deposited:	28 Dec 2011 07:19
Last Modified:	13 Feb 2012 04:56
URI:	http://ihbt.csircentral.net/id/eprint/307

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