The current review summarizes the published data on transition metal complex-mediated chemistry of 1,3,5-cycloheptatrienes. It addresses homodimerization of cycloheptatrienes and cyclocodimerization of the latter with alkenes, dienes and alkynes in the presence of transition metal complexes that occur via [2π + 2π], [3π + 2π], [6π + 2π], [6π + 4π] and [6π + 2π + 2π] cycloadditions. Special attention is given to the application of these reactions in the synthesis of valuable strained bi-, tri- and polycyclic compounds and for the development of methods of stereoselective synthesis of natural products. The bibliography includes 91 references.

A new, effective catalytic system based on Co(acac) has been developed for [6 + 2] cycloaddition of terminal alkynes to 1,3,5,7-cyclooctatetraene to give substituted bicyclo[4.2.2]deca-2,4,7,9-tetraenes in high yields (68-85%). The electrophilic activation of double bonds in the bicyclic products with m-CPBA is an efficient method for the synthesis of substituted bicyclo[4.3.1]deca-2,4,8-triene-7,10-diols, which form the key structural moieties of numerous natural biologically active compounds. The structures of the obtained compounds were reliably proven by modern spectral methods and X-ray diffraction. The mechanism of the discovered rearrangement was studied both using deuterium-labeled bicyclo[4.2.2]deca-2,4,7,9-tetraenes and utilizing quantum chemical calculations. The obtained substituted bicyclo[4.3.1]deca-2,4,8-triene-7,10-diols and their keto derivatives showed high antitumor activity in vitro against Hek293, Jurkat, K562, and A549 tumor cell lines.

The [6π + 2π]-cycloaddition of alkynes to 1-methyl-, propyl-, benzyl-, and hydroxymethyl-substituted 1,3,5cycloheptatrienes in the presence of catalytic systems Ti(acac) 2 Cl 2 -Et 2 AlCl and Co(acac) 2 (dppe)/Zn/ZnI 2 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.