Fig. 4: Scope of asymmetric cyclopropanation of N-propargyl ynamides 3.

Reaction conditions: 3 (0.15 mmol), Cu(MeCN)₄PF₆ (0.015 mmol), L12 (0.018 mmol), NaBAr^F₄ (0.018 mmol), 2-MeTHF (3 mL), 0 °C, in vials; yields are those for the isolated products; ees are determined by HPLC analysis.