A formal [3,3]-sigmatropic rearrangement route to quaternary alpha-vinyl amino acids: use of allylic N-PMP trifluoroacetimidates.
Pd(II)-mediated rearrangement of allylic N-PMP (p-methoxyphenyl) trifluoroacetimidates provides the first formal sigmatropic route to quaternary, alpha-vinylic amino acids, potential suicide substrates for PLP enzymes. The amino acid side chains enter via transition-metal-mediated C-C bond constructions, including (i) Cu(I)-mediated conjugate addition (Ala); (ii) Pd(0)/AsPh3-mediated Stille coupling (allyl-Gly, Phe, DOPA, m-Tyr); and (iii) Pd(0)/Pt-Bu3-mediated Negishi coupling (Leu). In the synthesis of the DOPA decarboxylase inactivator, alpha-vinyl-m-tyrosine, the new N-PMP trifluoroacetimidate rearranges much more efficiently than the corresponding trichloroacetimidate.
Berkowitz
David B
DB
Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, USA. dbb@unlserve.unl.edu
Wu
Bin
B
Li
Huijie
H
D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry*; D002384:Catalysis; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D007096:Imidoesters / Q000737:chemistry*; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry; D013237:Stereoisomerism
D000596:Amino Acids; D006845:Hydrocarbons, Fluorinated; D007096:Imidoesters; D010165:Palladium