LAUSR

A convenient method to prepare Ni(cod)2 from Ni(acac)2 using light as the source of energy is reported. In the first step of this process, xanthone is reductively dimerized upon irradiation of solar or LED light in 2-propanol to form a vicinal diol possessing a highly sterically congested C–C bond. In the second step, a ketyl radical derived from the diol reacts with Ni(acac)2, ultimately reducing nickel(II) to nickel(0), which is bound by 1,5-cyclooctadiene (COD) to produce Ni(cod)2. This new method obviates the need for hazardous reductants such as diisobutylaluminum hydride (DIBAH) and sodium.