The Phenylethylamine Auxiliary and Stereoselective Reductive Amination

Ketone classes Specific examples Yield (%) de (%) Acid cat. Comment O 

When comparing the stereoselectivity ofthe reductive amination products of (R) or (S) PEA, when using Ti(OiPr)4 (1.25 equiv) or Yb(OAc)3 (10mol%) or Y(OAc)3 (15 mol%) or Ce(OAc)3 (15 mol%) or Bronsted acids (catalytic or stoichiometric, e.g., AcOH), the de ofthe amine product is the same. Furthermore, taking the ketones used for these reductive amination studies and intentionally preforming and isolating the (R) or (S) PEA ketimines (Dean Stark trap synthesis) and reducing them in the same manner, albeit without the presence of the Lewis acid or Bronsted acid, the de is the same as that found for the reductive amination [34]. 

In stark contrast to these stereochemical trends, 2 alkanones without branching at 

Moving to asymmetric methods, they found Noyori s enantioselective transfer 

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