Atroposelective Synthesis of Enamine‐Based Axially Chiral Styrenes via CuH‐Catalyzed Hydroamination of Internal Alkynes

Despite the significant potential of axially chiral enamines, their efficient synthesis remains a challenge. Herein, we report a new approach for the diverse synthesis of enamine-based axially chiral styrenes via a copper-catalyzed atroposelective hydroamination of internal alkynes. This method features good functional group tolerance, exclusive regio- and E-selectivity, and excellent enantioselectivities (up to 98% ee). Experimental and DFT studies were performed to elucidate the mechanism and rationalize the origin of enantioselectivity. Furthermore, the reaction is readily scalable to gram quantities, and the resulting products can be transformed into chiral N,P-ligands, thereby enriching the family of axially chiral ligands with new members.