Transition metal boryl complex

In chemistry, a transition metal boryl complex is a molecular species with a formally anionic boron center coordinated to a transition metal. They have the formula L_nM-BR₂ or L_nM-. One example is Mn₂. Such compounds, especially those derived from catecholborane and the related pinacolborane, are intermediates in transition metal-catalyzed borylation reactions.
File:KUHPAG.png|thumb|left|Structure of ₄RhB..

Synthesis

Oxidative addition is the main route to metal boryl complexes. Both B-H and B-B bonds add to low-valent metal complexes. For example, catecholborane oxidatively adds to Pt to give the boryl hydride.
Addition of diboron tetrafluoride to Vaska's complex gives the triboryl iridium derivative: