Double Bond Isomerization/Enantioselective Aza-Petasis-Ferrier Rearrangement Sequence as an Efficient Entry to Anti- and Enantioenriched β-Amino Aldehydes

Highly anti- and enantioselective synthesis of beta-amino aldehydes having an aliphatic substituent. at the beta-position was accomplished by a combination of two catalytic reactions, that is, an initial Ni(II) complex-catalyzed isomerization of a double bond followed by a chiral phosphoric acid catalyzed aza-Petasis-Ferrier rearrangement, using hemiaminal allyl ethers as the initial substrate. The chiral phosphoric acid also functioned as an efficient resolving catalyst of racemic hemiaminal vinyl ethers.