The adduct [MeO → Bpin–Bpin]− efficiently mediates the β-boration of α,β-unsaturated imines formed in situ. The use of chiral phosphines as additives, and in particular the chiral phosphine (S)-MeBoPhoz, enables the catalytic asymmetric reaction to proceed with higher enantioselectivity than the analogue copper(I) mediated reaction.
![](https://www.iciq.org/wp-content/uploads/2015/08/15-OBC-CB-1328.gif)