A DBU-promoted cascade annulation of nitroarylcyclopropane-1,1-dicarbonitriles and 3-aryl-2-cyanoacrylates for the synthesis of highly functionalized cyclopenta­[b]­furan derivatives is described. High stereoselectivity, fused cyclopentane and furan can be established in a single reaction, highlighting the high efficiency and step-economy of this protocol. This reaction offers a novel and straightforward protocol to the synthesis of cyclopenta­[b]­furans featuring the [3 + 2] cycloadditions of nitroarylcyclopropane-1,1-dicarbonitriles with 3-aryl-2-cyanoacrylates.

Multisubstituted furan derivatives were synthesized effectively using the DBU-mediated, unprecedented formal ring expansion reactions of 2-acyl-3-arylcyclopropane-1,1-dicarbonitriles.

DBU-promoted cascade selective nucleophilic addition/C–C bond cleavage/hetero-Diels–Alder reactions accompanied by aromatization of substituted 2-amino-4H-chromen-4-ones with substituted β-nitrostyrenes or with the combined substituted β-nitrostyrenes and aromatic aldehydes were developed for the synthesis of 2,4-diaryl-substituted 5H-chromeno­[2,3-b]­pyridin-5-ones. This procedure provides a highly efficient and facile route to functionalized 5H-chromeno­[2,3-b]­pyridines from readily available substrates under mild reaction conditions.

DBU-mediated cyclization of 2-acyl-1-cyanocyclopropanecarboxylates with amidines for the synthesis of multisubstituted pyrimidine derivatives is described. This reaction gives a practical method for producing a diverse set of pyrimidines, having simple experimentation, readily available starting materials, a wide substrate scope, and very good yields.

A convenient and straightforward strategy to synthesize Z-configuration chalcones with alkylcyanoacetate subunit via DBU-promoted ring-opening reactions of multi-substituted D-A cyclopropane has been developed. This reaction did not require transition metal...