Nickel-Catalyzed Enantioselective Direct Addition of Styrenes to Imines Enabled by Chiral Spiro Phosphine Ligands.

Enantioenriched allylic amines are key structural motifs found in a wide array of bioactive molecules and serve as versatile intermediates in organic synthesis. Despite significant advances in their preparation, the enantioselective direct addition of simple alkenes to imines has remained a formidable challenge. Herein, we report a nickel(0)-catalyzed enantioselective direct addition of styrenes and their derivatives to aldimines, enabled by a newly developed family of electron-rich, C2-symmetric chiral spiro monophosphine ligands based on the tetramethyl-1,1'-spirobiindane scaffold. This method features highly efficient, atom-economical construction of chiral allylic amines with excellent regio- and enantioselectivities under mild conditions, and exhibits broad functional group tolerance.