Redox Reactions Oxidative Addition and Reductive Elimination

Redox Reactions Oxidative Addition and Reductive Elimination 

Coordinatively unsaturated transition metal complexes can in general add neutral or anionic nucleophiles. Oxidative addition to coordinatively unsaturated transition metal compounds has opened up undreamt of synthetic possibilities [18]. This reaction and its reverse — reductive elimination — are formally described by the following equilibrium  

In general, the bonds of small covalent molecules XY (H-X, C-X, H-H, C-H, C-C, etc.) add to a low oxidation state transition metal, whose oxidation state then increases by two units. The reaction is mainly observed with complexes of d and d ° transition metals (e.g., Fe , Ru , Os , Rh, Ir, Ni , Pd , Pt , Pd , Pt ). The reaction can take two possible courses  

1) The molecules being added split into two r/ ligands, which are both formally anionically bound to the metal center. One of the most thoroughly investigated compounds is a square-planar iridium complex whose central atom gives up two electrons and is oxidized to Ir (Eq. 2-32). 

2) The molecules being added contain multiple bonds and are bound as tf ligands, without bond cleavage. The resulting complexes contain three-membered rings, as shown in Equations 2-33 and 2-34. 

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