The single electron transfer reagent samarium(II) diiodide (SmI2) has rapidly become a widely used reagent for selective reduction and reductive coupling reactions.
We have recently discovered that addition of H2O and an aliphatic amine results in a very powerful reductant. The SmI2/H2O/amine mixture has been found to mediate quantitative and instantaneous reductions of a wide variety of functional groups. In addition, H2O is used as a very cheap and non-explosive hydrogen source.
The long-term goal is to determine the scope and the limitations of the SmI2/H2O/amine reagent for various reduction reactions. Mechanistic methods can constitute a tool for further development of this class of chemistry. The use of other lanthanide(II) reagents (i.e. SmBr2 and YbI2) in combination with amine and water is currently being explored.