Carbon-carbon double bonds are key skeletal units in a plethora of natural and industrial chemicals as well as versatile precursors for many synthetic transformations. Despite the availability of numerous protocols for installing olefin functional group (e.g., olefination, elimination, condensation, dehydrogenation), such transformations are frequently disadvantaged by low stereoselectivities or restrictions on functional groups. Alternatively, transposition of pre-existing olefins offers a powerful and atom-economical route to incorporate and manipulate C=C bonds with far-reaching applications in industrial production e.g., pharmaceuticals, cosmetics, fragrances, polymers and fuels. Various processes were developed with efficient catalysts based on transition metals: Ir, Rh, Pd, Ru, Cr, Co, 10 Ni, Fe, W, among others. (Figure ). Missing in this set of examples is a highly abundant and biocompatible manganese metal that remains unknown in olefin transposition so far.