Samarium diiodide may be a useful reagent in a step of an asymmetric synthesis process. It can release a blocking group in mild conditions, as described in several examples. SmI2 has been used as electron donor in many C–C bond formations in presence of a chiral auxiliary. It can also generate samarium enolates which were subjected to asymmetric protonation. The examples selected in this review of SmI2 methodology concern only the cases where the chiral auxiliary is not retained in the final product.
