Enantioselective Allylation of Imines Directed by Phenols

Significance

The use of a phenol-directing group activates the allylation reagent 2, thus providing access to chiral homoallylic amines under simple reaction conditions. The phenol moiety can either be used as a protecting group and oxidatively cleaved in the case of aldimines 1 and 4, or it can be part of the molecule, as for ketimines like 7. Noteworthy is the rapid one-pot synthesis of functionalized cyclic chiral amines. Indeed, upon addition of Grubbs II catalyst to the reaction mixture of 8, enantiopure heterocycles bearing tertiary carbin­amines are obtained efficiently (82-90%, 96-98% ee).