Lewis acid mediated allylations of β-alkoxy -tosyl imines using allyltrimethylsilane lead to 3-alkoxy homoallylic -tosyl amines with selectivity. Two methods of Cu(OTf)-mediated allylations are reported herein, demonstrating that diastereoselectivity can be achieved through 1,3 acyclic stereocontrol of β-chiral aldimines. Observed selectivity trends and computational evidence suggest selectivity arises through the formation of a six-membered ring chelate. The product ratios of these allylations are dependent on conformational preferences of the chelate and steric effects in the transition-state structures.
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