Aluminum contains three valence electrons and is the most electropositive element in the p-block. Examples of synthesizing transition-metal complexes with a three-coordinated aluminum ligand remain limited. They can be classified to the following methods: A nucleophilic attack of anionic transition-metal
complexes to an aluminum electrophile, the coordination of a base-stabilized Al species to a metal, elimination of alkane via a metathesis reaction, an oxidative addition of an Al–H bond to a metal center in a low oxidation state, insertion of Al species into a metal-halogen bond, and transmetallation of the Al anions to metal halides. In the presentation, our latest contribution to the chemistry of early transition metal-aluminum and main group metal-aluminum complexes using the method will be discussed.