Aza-Petasis-Ferrier rearrangement

The same catalyst has been used by this research group in synthesis of j -amino-aldehydes (146) by combining two catalytic reactions, i.e. a Ni(II) complex-catalyzed isomerization of a double bond and a chiral phosphoric acid (127)-catalyzed aza-Petasis-Ferrier rearrangement in a highly dia-stereo- and enantioselective manner (Scheme 39). ... 

Scheme 7.58 Tandem isomerisation-aza-Petasis-Ferrier rearrangement reaction catalysed by nickel catalysis and chiral phosphoric acid catalysis followed by reduction.

The aza-Petasis-Ferrier rearrangement is not a true concerted sigmatropic reaction, since it is thought to proceed via C-O bond cleavage of a hemiaminal vinyl ether by the action of an acid catalyst to afford a reactive iminium cation and the enol form of an aldehyde these two intermediates combine subsequently in a Mannich-type process, leading to 3-amino aldehydes (Scheme 40.45) [54]. Recently, Terada and Toda used a BINOL-derived phosphoric acid diester as a catalyst for this interesting reaction [55]. 

Scheme 40.45 Acid-catalyzed aza-Petasis-Ferrier rearrangement.

Subsequently, the same group demonstrated an asymmetric synthesis of 3-amino aldehydes via catalytic double-bond isomerization/enantioselective aza-Petasis-Ferrier rearrangement reaction (Scheme 2.93) [128]. Similarly, the hemiaminal allyl ether substrates 346 were first isomerized by Ni(II) complexes to stereoselectively form Z-configured vinyl ethers 347, which then underwent a phosphoric acid-catalyzed... 

Korenaga and co-workers reported the precise mechanism of the highly anti- and enantioselective aza-Petasis-Ferrier (APF) rearrangement of hemiaminal vinyl ethers (254) catalysed by a chiral phosphoric acid (265) which has been investigated by both experimental and theoretical studies (Scheme 71). ... 

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