Cobalt(I)-Catalyzed Cycloaddition of Functionally Substituted Alkynes and 1,3-Diynes to 1,3,5,7-Cyclooctatetraene in the Synthesis of Bicyclo[4.2.2]deca-2,4,7,9-tetraenes

Synthesis and application of 3,4,7,8-tetrakis-exo-methylenecycloocta-1,5-diene as a versatile Diels–Alder diene: synthesis of V-shaped cyclooctatetraene fused acenes

Synthesis of 3,4,7,8-tetrakis-exo-methylenecycloocta-1,5-diene, has been reported. Diels-Alder reactions with this diene provides a shorter route for the synthesis of cyclooctatetraene fused with rigid aromatic wings.

The Synthesis of Bicyclo[4.2.1]nona-2,4,7-trienes by [6π + 2π]-Cycloaddition of 1-Substituted 1,3,5-Cycloheptatrienes Catalyzed by Titanium and Cobalt Complexes

The [6π + 2π]-cycloaddition of alkynes to 1-methyl-, propyl-, benzyl-, and hydroxymethyl-substituted 1,3,5-cycloheptatrienes in the presence of catalytic systems Ti(acac)₂Cl₂-Et₂AlCl and Co(acac)₂(dppe)/Zn/ZnI₂ was performed for the first time to give practically valuable bicyclo[4.2.1]nona-2,4,7-trienes in high yields (72-88%). The structures of the obtained bicyclic compounds were reliably proved by NMR methods and X-ray diffraction analysis. The newly synthesized bicycles have been investigated for their in vitro cytotoxic activity against Jurkat, K562, U937, and HL60 tumor and normal cell lines and induction of apoptosis.