Catalysis and Synthesis Enabled by P-Chiral Dihydrobenzooxaphosphole Ligands

P-Chiral phosphorus ligands received little attention in organic chemistry until Knowles made his landmark contribution in asymmetric hydrogenation by developing the P-chiral ligands CAMP and DIPAMP. The development of P-chiral phosphorus ligands accelerated in the end of the last century with the advent of some highly efficient and renowned ligands for asymmetric hydrogenation, including BisP*, TangPhos, QuinoxP*, DuanPhos, et al. However, most reported ligands were air-sensitive, difficult to make, or lacked structural modularity, hampering their availability and applicability. The development of sterically and electronically tunable P-chiral phosphorus ligands is particularly desirable. Over the past decade, a family of sterically hindered, electron-rich, structurally tunable, and air-stable P-chiral dihydrobenzooxaphosphole ligands emerged that proved to be efficient and versatile for various asymmetric transformations. The last 5 years witnessed an increasing number of studies related to these ligands with the discovery of their unprecedented catalytic properties in various transformations. This review highlights the unique properties of P-chiral dihydrobenzooxaphosphole ligands in catalysis and their applications in the synthesis of natural products and therapeutic agents.