A new set of C1-symmetric chiral bisphosphine ligands was developed from hydroxybenzothiol, 2-(diphenylphosphaneyl)-benzoic acid and chiral aziridine. These ligands were utilized for the Pd-catalyzed asymmetric allylic substitution reaction. Under the optimal conditions, structurally diverse hard/soft nucleophiles, such as activated methylene compounds, amines, alcohols, and indole were investigated, and the corresponding products were obtained in good yields and excellent ees. Even under low catalyst loading and gram-scale reaction conditions, the product was obtained in good yield with excellent enantioselectivity, which further validated the promising practical application potential of this ligand.
Feng et al. (Sun,) studied this question.