New polydentate ligands based on sterically hindered o-benzoquinones (pyrocatechols) containing the 1,4-diazadiene group

Synthesis of dibromo- and tetrabromo-bipyrrolines and their corresponding 2,6-diazasemibullvalene derivatives

Treatment of Δ¹-dipyrrolines with NBS afforded α,α′-dibromo-Δ¹-bipyrrolines and α,α,α′,α′-tetrabromo-Δ¹-bipyrrolines, which were efficiently transformed into 2,6-diazasemibullvalene derivatives via reduction with lithium.

Efficient synthesis of aza-triquinacene derivatives via cycloaddition of 2,6-diazasemibullvalenes with nitroso compounds

The reaction between 2,6-diazasemibullvalenes and nitroso compounds was investigated. Aza-triquinacene derivatives of interesting structural and synthetic chemistry were generated highly selectively in good to excellent isolated yields. This reaction, which was rarely found between common aziridine derivatives and nitroso compounds, could be attributed to the rigid polycyclic ring system and the substitution patterns of 2,6-diazasemibullvalenes. Δ(1) -Bipyrroline derivatives were formed in excellent yields when these aza-triquinacene derivatives were treated with SmI2 .

Intramolecular cyclization–decyclization of new sterically hindered diiminophenol. Synthesis and coordination abilities

The novel benzoxazole I undergoes a fast intramolecular decyclization and demonstrates either a neutral or anionic coordination type in cadmium complexes.