2+2+2] cycloaddition reactions of α,β-unsaturated N-arylaldimines, acetylenedicarboxylates and 2-arylidene-1,3-indanediones

Abstract

The domino [2+2+2] cycloaddition reaction of α,β-unsaturated N-arylaldimines, dialkyl acetylenedicarboxylates and 2-arylidene-1,3-indanediones in dry methylene dichloride at room temperature afforded isomeric 2′-styryl-1,2′,3,4′-tetrahydro-1′H-spiro[indene-2,3′-pyridines] in good yields. Under similar conditions, the reaction of α,β-unsaturated N-arylaldimines with two molecules of dialkyl acetylenedicarboxylates resulted in 1-aryl-6-styryl-1,6-dihydropyridine-2,3,4,5-tetracarboxylates. Additionally, the three-component reaction of α,β-unsaturated N-arylaldimines, dimethylacetylenedicarboxylate and benzoyl cyanide also gave isomeric 1,3-oxazine-4,5-dicarboxylates.