N‐Heterocyclic Carbene Catalyzed [3+2] Cycloaddition of Enals with β,γ ‐Unsaturated α ‐Ketimino Esters for the Synthesis of Multisubstituted Cyclopentanone

Abstract A convenient strategy of N ‐heterocyclic carbene catalyzed [3+2] cycloaddition of enals with β,γ ‐unsaturated α ‐ketimino esters is developed. This effective protocol features mild reaction conditions and broad substrate scope, which enables the rapid assembly of various benzoxazinone derived cyclopentanone scaffolds in good to high yields with excellent diastereoselectivities. magnified image