Fig. 4: Scope with respect to 2-vinylindoles.

Unless other noticed, reactions were performed with 1 (0.10 mmol), 2a (0.12 mmol), P10 (0.01 mmol), and Cs₂CO₃ (0.60 mmol) in Et₂O (2.0 mL) at −20 °C for 72 h; then BF₃·Et₂O (1.0 mmol) was directly added to the reaction mixture which was further stirred at r.t. for 12 h. Isolated yield. The e.e. value was determined by HPLC analysis on a chiral stationary phase.