Sequential Organocatalytic Synthesis of [1,2,3]Triazolo[1,5-a]quinolines

In this work, a one-pot sequential organocatalytic method for the synthesis of fused [1,2,3]triazolo[1,5-a]quinolines through successive cyclization and condensation is presented. In this synthetic strategy, the intermolecular [3+2]-cycloaddition occurs between 1,3-dicarbonyl compounds ando-carbonyl-substituted phenylazide compounds, for the formation of the 1,2,3-triazole intermediates. Subsequently, an intramolecular condensation reaction generates the fused quinoline ring by the new C-C bond formation, giving the products in yields ranging from moderate to excellent. All the reactions were performed using 20 mol% of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as catalyst in the presence of DMSO as solvent at 120 degrees C for 24 h and tolerate a range of 1,3-dicarbonyl compounds, such as beta-keto esters and 1,3-diketones, ando-formyl,o-acetyl oro-benzoyl substituted phenylazide compounds.