Iodine-mediated solvent-controlled selective electrophilic cyclization and oxidative esterification of o-alkynyl aldehydes: an easy access to pyranoquinolines, …

AK Verma, V Rustagi, T Aggarwal…

Index: Verma, Akhilesh K.; Rustagi, Vineeta; Aggarwal, Trapti; Singh, Amit P. Journal of Organic Chemistry, 2010 , vol. 75, # 22 p. 7691 - 7703

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Citation Number: 55

Abstract

Chemoselective behavior of iodine in different solvents in the electrophilic iodocyclization of o-alkynyl aldehydes is described. o-Alkynyl aldehydes 3a− t on reaction with I2 in CH2Cl2 with appropriate nucleophiles provides pyrano [4, 3-b] quinolines 4a− f, via formation of cyclic iodonium intermediate Q; however, using alcohols as a solvent as well as nucleophile, o-alkynyl esters 5a− y were obtained selectively in good to excellent yields via formation ...