Homoallylic amines (see 4 and 8 for general structures) are a fundamental class of compounds featured in many pharmaceuticals,agrochemicals,and ligands to transition metals.Numerous elegant methods have been developed to construct these compounds over the years.To date,the most well-established methods involve the nucleophilic attack of an allylmetal reagent (2) to an imine (1),which always give 1,2-disubstituted homoallylic amines such as 4,as controlled by transition states like 3.Umpolung reaction of imines,in which imines function as nucleophiles,represents a new paradigm for chiral amine synthesis.This unconventional,polarity reversal strategy may allow new ways of bond connection and access to compounds that are historically difficult to prepare.Here we describe such an example.A catalytic asymmetric umpolung allylation of imines that yields 1,4-disubstituted homoallylic amines has been developed (5+6 to 8 via 7).This reaction proceeds by a cascade that involves an iridium-catalyzed,regioselective allylation of imine 5 by 6 that gives intermediate 7,and a following facile 2-aza-Cope rearrangement of 7 that ultimately leads to the formation of 8.This reaction furnishes homoallylic amines with a 1,4-disubstitution pattern (cf.8),compounds that are very challenging to prepare using traditional,non-Umpolung methods.