**4. Conclusions**

Thus, the catalytic alkene hydro‐, carbo‐ and cycloalumination are complex multi‐step pro‐ cesses, in which a large number of intermediate bimetallic Zr, Al‐complexes are involved. Studies of the reaction mechanisms allow to understand the chemistry of the processes on a deeper level and to narrow the search for new catalytic systems.

Finally, the next remarks should be sound. First, the initial OACs exist as self‐associated struc‐ tures in the solutions, where the exchange between hydride atoms or alkyl groups could run via dissociation on monomers, which represents the Lewis acids and which effective concen‐ tration influences on the stages of key intermediates formation. Second, since the catalyst (IV group transition metals) is a Lewis acid too due to a free nonbonding orbital, then it disturbs the above balance, making the system more dynamic. Thus, one of the important roles of the catalyst besides the formation of active species is to accelerate the exchange through the disso‐ ciation with the release of the active OAC monomer. Third, the interaction of alkyl or hydride complex with the monomer gives active species—bimetallic intermediates, which reactivity depends on the availability of the free nonbonding orbital (**Scheme 9**). The active species should be coordinatively unsaturated, where at least one of the bridge bond is broken. In the case of bimetallic hydride complexes, there is the tendency to form inactive bridge bonds, whereas bimetallic alkyl substituted intermediates are inclined to the dissociation. Therefore, the activity of intermediates depends on the living time of active species, in which the electro‐ philicity of the metal center could be increased via η<sup>5</sup> ‐ligand, thereby accelerating the process of alkene introduction. However, there is a danger of another process—C─H activation in the products, which could be prevented by using more bulky ligands or more polar solvents. Alkene and Olefin Functionalization by Organoaluminum Compounds, Catalyzed... http://dx.doi.org/10.5772/intechopen.69319 57

**Scheme 9.** Exchange processes in bimetallic intermediates as factors that determine the properties of catalytic systems.

Fourth, the activity of catalytic systems and the degree of asymmetric induction in catalytic alkene functionalization by OACs is substantially affected by the intramolecular ligand mobil‐ ity and conformational composition of the bimetallic intermediates.

Thus, the regulation of activity, chemo‐ and stereoselectivity of the studied systems is the problem of fine tuning of the catalytically active center, in which should be a balance between electronic and steric factors of the catalyst, OAC and the substrate.
