Sparteine Family: Privileged Chiral Ligands in Transition Metal Catalysis

Chiral ligands are the footstones for asymmetric synthesis, constructing the enantio-enriched molecules that are widely used in material and medicinal sciences. Naturally occurring compounds, such as proline analogues and cinchona alkaloids, are widely used as privileged ligands in asymmetric synthesis. Sparteine, a natural alkaloid firstly reported in 1968, was also employed in asymmetric synthesis, albeit with less satisfactory results. In this perspective, transition metal-involved asymmetric transformations using sparteine or family members as ligands are overviewed and discussed. The design and perspective of ligands with similar skeleton are also proposed.