Dehydrogenations are the most atom efficient way in order to generate element-element bonds in a condensation reaction. Metal complexes with cooperating ligands proved to be especially effective in these reactions. Some special metal complexes will be reported which benefit from electronic and steric effects of amido olefin ligands which facilitate these reactions in homogeneous solution.
Specifically, complexes of type A with various metals including those from the 4th row like Ni or Fe and L = phosphines or carbenes show promising properties and catalyze alcohol dehydrogenations and dehydrogenations of amino boranes and silanes. Likewise, metal diazadiene complexes of type B show remarkable catalytic efficiencies and convert methanol/water mixtures or aqueous formaldehyde solutions cleanly into hydrogen and carbondioxide. Some insight into the mechanism of these reactions will be presented.