Conjugated nitroalkenes in cycloaddition reactions. Part 2. Diels–Alder reactions of E-2-aryl-1-cyano-1-nitroethenes with cyclopentadiene

Abstract

The reaction between E-2-aryl-1-cyano-1-nitroethenes 1a–1e and cyclopentadiene (2) occurs according to the carbodiene [4+2]cycloaddition scheme and leads to the corresponding 6-endo-aryl-5-endo-cyano-5-exo-nitronorbornenes 3a–3e and 6-exo-aryl-5-exo-cyano-5-endo-nitronorbornenes 4a–4e as the only reaction products. The attempts to detect the products of heterodiene [4+2]cycloaddition in the reaction environment were not successful.