Palladium(0)-Catalyzed Isomerization Reactions of Aziridines Bearing an alpha,beta-Unsaturated Ester Group: A Thermodynamic Preference for Chiral Alkyl (2E)-4,5-cis-4,5-Epimino-N-(alkyl- or arylsulfonyl) 2-Enoates over the Other Three Stereoisomers.
Palladium(0)-catalyzed reactions of five sets of four stereoisomeric 4,5-epimino-N-(methanesulfonyl) or -N-(arylsulfonyl) 2-enoates reveal that 4,5-cis-(2E)-isomers are thermodynamically more stable than other isomers, in accord with calculations. A highly stereoselective synthesis of (E)-alkene dipeptide isosteres having the desired stereochemistries from unwanted stereoisomeric 4,5-epimino-N-(arylsulfonyl) 2-enoates is also presented.
Ibuka
Toshiro
T
Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980, Japan.
Mimura
Norio
N
Ohno
Hiroaki
H
Nakai
Kazuo
K
Akaji
Masako
M
Habashita
Hiromu
H
Tamamura
Hirokazu
H
Miwa
Yoshihisa
Y
Taga
Tooru
T
Fujii
Nobutaka
N
Yamamoto
Yoshinori
Y