1235868-42-4Relevant articles and documents
Iodine-catalyzed and solvent-controlled selective electrophilic cyclization and oxidative esterification of ortho-alkynyl aldehydes
Verma, Akhilesh Kumar,Aggarwal, Trapti,Rustagi, Vineeta,Larock, Richard C.
supporting information; experimental part, p. 4064 - 4066 (2010/09/05)
4-Iodo-pyrano[4,3-b]quinolines and ortho-alkynyl esters were synthesized selectively from ortho-alkynyl aldehydes by an iodine-catalyzed and solvent controlled reaction.
Iodine-mediated solvent-controlled selective electrophilic cyclization and oxidative esterification of o-alkynyl aldehydes: An easy access to pyranoquinolines, pyranoquinolinones, and isocumarins
Verma, Akhilesh K.,Rustagi, Vineeta,Aggarwal, Trapti,Singh, Amit P.
experimental part, p. 7691 - 7703 (2010/12/29)
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 of hypoiodide intermediate R. Subsequently, o-alkynyl esters were converted in to pyranoquinolinones 6a-i and isocoumarin 6j by electrophilic iodocyclization. This developed oxidative esterification provides a novel access for the chemoselective synthesis of esters 5q-u from aldehydes 3n-p without oxidizing primary alcohol present in the substrate.
