@article { ISI:000237485300010,
	title = {Ligand-, copper-, and amine-free one-pot synthesis of 2-substituted indoles via Sonogashira coupling 5-endo-dig cyclization},
	journal = {Tetrahedron},
	volume = {62},
	number = {21},
	year = {2006},
	month = {MAY},
	pages = {5109-5115},
	publisher = {PERGAMON-ELSEVIER SCIENCE LTD},
	type = {Article},
	address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND},
	abstract = {<p>Results of the optimized conditions for the one-pot synthesis of 2-substituted indoles via palladium acetate catalyzed tandem Sonogashira coupling 5-endo-dig cyclization at room temperature under ultrasonic irradiation and standard stirred conditions are described. Electron-donating and electron-withdrawing groups present in both Coupling partners were well tolerated under these mild conditions. A copper-, ligand- and amine-free condition is an important feature of this protocol. Significant enhancement of reaction rates was observed for the reactions employing ultrasonic irradiation. (c) 2006 Elsevier Ltd. All rights reserved.</p>},
	keywords = {5-endo-dig cyclization, Indole, synthesis, Ultrasound},
	issn = {0040-4020},
	doi = {10.1016/j.tet.2006.03.035},
	author = {Palimkar, Sanjay S. and Kumar, P. Harish and Lahoti, Rajgopal J. and Srinivasan, Kumar V.}
}
@article { ISI:000254443900045,
	title = {Efficient synthesis of 1,8-dioxo-octahydro-xanthene derivatives promoted by a room temperature ionic liquid at ambient conditions under ultrasound irradiation},
	journal = {Ultrasonics Sonochemistry},
	volume = {15},
	number = {4},
	year = {2008},
	month = {APR},
	pages = {548-553},
	publisher = {ELSEVIER SCIENCE BV},
	type = {Article},
	address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	abstract = {<p>The condensation reaction involving an aldehyde and diketone was efficiently promoted by the Ionic liquid, [Hbim]BF(4) (IL) as a reaction medium with methanol as co-solvent at ambient temperature under ultrasonic irradiation to afford the corresponding 1,8-dioxo-octahydroxantliene (xanthene) derivatives in excellent yields. The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid, which promotes this protocol under ambient temperature without the requirement of ally added catalyst. The reaction times and yields are compared with p-TSA catalyzed synthesis of xanthenes under thermal conditions, which is also reported for the first time under our reaction conditions. (c) 2007 Elsevier B.V. All rights reserved.</p>},
	keywords = {aldehydes, ambient conditions, Bronsted acidity, dimedone, Ionic liquid, Ultrasound, Xanthenes},
	issn = {1350-4177},
	doi = {10.1016/j.ultsonch.2007.06.001},
	author = {Venkatesan, K. and Pujari, Suresh S. and Lahoti, Rajgopal J. and Srinivasan, K. V.}
}
