An NHC-catalyzed, regio- and stereoselective oxidative cyclization of o-alkynylbenzaldehydes bearing an unactivated alkyne moiety as an internal electrophile has been developed to afford phthalides and isocoumarins. A single organocatalytic system enabled two sequential C-O bond formations to take place in an atom economical manner via highly efficient dual activation. Molecular oxygen in air could be utilized as a source of an oxygen atom for the oxidation of aldehydes to the corresponding benzoic acids under our newly developed reagent system.

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Various di-and mono-substituted quinazolinones were synthesized by one-pot condensation of isatoic anhydride, aldehyde and amine, or ammonium carbonate using [bmim]HSO 4 as catalyst in aqueous medium. Water as a reaction media, recyclability of catalyst, shorter reaction time, and good yields (70Á90%) are some of the salient features of the developed protocol.

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