Metal Free Domino β-Azidation/[3 + 2] Cycloaddition Reaction for the Synthesis of 1,2,3-Triazole-Fused Dihydrobenzoxazinones.

A metal free DBU catalyzed synthesis of 1,2,3-triazole-fused dihydrobenzoxazinone derivatives by tandem β-azidation/[3 + 2] cycloaddition reaction has been developed under mild conditions. The methodological studies offer a broad scope and proceed well with a wide range of alkynylated cyclohexa 2,5-dienones, giving new cis-triazole-fused tricyclic scaffolds.