Asymmetric synthesis of α-alkenyl homoallylic primary amines via 1,2-addition of Grignard reagent to α,β-unsaturated phosphonyl imines.

A series of chiral N-phosphonyl protected α-alkenyl homoallylic primary amines were synthesized by asymmetric addition of allylmagnesium bromide Grignard reagent towards chiral α,β-unsaturated imines. Only 1,2-adduct was obtained for all the imines with good yields and excellent diastereoselectivities. The chiral auxiliary could be easily removed under simple conditions, giving free multiple functionalized primary amines.