Figure 1.

Asymmetric diamination of 1-phenyl-1,3-butadiene (1a) with chiral Cu(I) salts. All reactions were carried out with olefin (0.20 mmol), 1,2-di-tert-butyldiaziridinone (2) (0.40 mmol), R*XCu-PPh₃ (1:2) (0.020 mmol) in C₆D₆ (0.2 mL) at rt under argon for 24 h. RXCu was prepared in situ by stirring mesitylcopper(I) and R*XH in dry C₆D₆ for 1 h, followed by treating with PPh₃ at rt for 1 h. In the cases of Y2, Y4, and Y5, no PPh₃ was used.