Enantioselective Zn-catalyzed hydrophosphinylation of nitrones: an efficient approach for constructing chiral α-hydroxyamino-phosphine oxides.

Although enantioselective hydrofunctionalizations of nitrones are established for the synthesis of various types of chiral hydroxylamines, the asymmetric catalytic hydrophosphinylation of nitrones remains highly challenging. Herein, an efficient asymmetric hydrophosphinylation of nitrones, catalyzed by the dinuclear zinc catalyst derived from ProPhenol, is presented, accommodating a variety of nitrones and phosphine oxides. This approach successfully addresses the long-standing challenge of catalytic hydrophosphinylation of the C[double bond, length as m-dash]N bond, and offers an efficient and rapid access towards chiral α-hydroxyamino-phosphine oxides. Control experiments suggest that the oxide anion in the nitrone motif is crucial for the enantio-control.