Samarium(II) Ate Species Combined With Aminoalcohols as Reductants for Hydrogenation of Unsaturated Organic Compounds

We explored the samarium(II)‐mediated reduction of unsaturated organic compounds using aminoalcohols as protic ligands. By screening various anionic (pseudo)halide ligands and their stoichiometry at the samarium(II) center, we found that samarium(II) ate species coordinated by chloride ligands exhibited superior reactivity. Furthermore, hydroxyethyl‐substituted ethylenediamine proved to be an effective supporting ligand as well as a proton source for the reduction of unsaturated organic compounds. UV–vis analyses of the anion exchange between SmI 2 and halide sources (2 vs. 3 equiv.) revealed distinct absorption spectra depending on the amount of chloride, whereas bromide showed no significant spectral change.