Enantioselective Synthesis\nof Chiral β<sup>2</sup>‑Amino Phosphorus Derivatives\nvia Nickel-Catalyzed Asymmetric\nHydrogenation

Compared\nwith chiral β<sup>3</sup>-amino phosphorus\ncompounds,\nwhich can be easily derived from natural optically pure α-amino\nacids, obtaining chiral β<sup>2</sup>-amino phosphorus derivatives\nremains a challenge. These derivatives, which cannot be derived from\nchiral natural amino acids, possess unique biological activities or\npotential catalytic activities. Herein, highly enantioselective hydrogenation\nfor the preparation of chiral β<sup>2</sup>-amino phosphorus\nderivatives from <i>E</i>-β-enamido phosphorus compounds\nis reported by using a green and low-cost earth-abundant metal nickel\ncatalyst (13 examples of 99% ee). In particular, this catalytic system\nprovides the same enantiomer product from the <i>E</i>-\nand <i>Z</i>-alkene substrates, and the <i>E</i>/<i>Z</i>-substrate mixtures provide good results (up to\n96% ee). The products can be diversely derivatized, and the derivatives\nexhibit good catalytic activities as novel chiral β<sup>2</sup>-aminophosphine ligands. Density functional theory calculations reveal\nthat the weak attractive interactions between the nickel catalyst\nand the substrate are crucial for achieving perfect enantioselectivities.\nIn addition, the different coordination modes between the <i>E</i>- or <i>Z</i>-substrates and the catalyst may\nresult in the formation of the same enantiomer product.