Copper-mediated imine–nitrile coupling leading to unsymmetric 1,3,5-triazapentadienato complexes containing the incorporated iminoisoindolin-1-one moiety

Abstract

The copper(II)-mediated integration between various 3-iminoisoindolin-1-ones and neat organonitriles (which play a dual role of solvent and reactant), under heating for ca. 12 h, and without requiring any base, accomplishes the release of the solid (1,3,5-triazapentadienato)Cu^II complexes [Cu{HN=C(R)NC(C₆R₁R₂R₃R₄CO)N}₂] (1–11) bearing the incorporated iminoisoindolin-1-one fragment. These compounds were isolated in moderate to good yields (44–78%) and do not require further purification. The iminoisoindolinone–nitrile coupling is Cu^II-mediated and has a general character insofar as it can be efficiently applied for both unsubstituted (R¹–R⁴ = H) and substituted iminoisoindolin-1-ones (R¹, R³, R⁴ = H, R² = Me; R¹, R⁴ = H, R², R³ = Cl; R¹–R⁴ = F), and a wide range of nitriles (R = Me, Et, Prⁿ, Prⁱ, C₆H₁₁, CH₂Ph). Complexes 1–11 were characterized by elemental analyses (C, H, N), FAB⁺-MS, IR spectroscopy, and additionally compounds 1, 2 and 4 by single-crystal X-ray diffraction.