Conjugate addition of nitroalkanes to an acrylate equivalent. Stereocontrol at C-alpha of the nitro group through double catalytic activation.
An unprecedented highly selective direct conjugate addition of prochiral nitroalkanes (R not equal H) to acrylate equivalents is described. The method employs a unique Lewis acid/Brønsted base/MS ternary catalytic system and affords products with dr up to 97/3. With beta-substituted (R' not equal H) acceptors unprecedented levels of anti/syn selectivity (>or=96/4) are attained. Adducts can be transformed into enantioenriched gamma-amino acids and derivatives, including aldehydes, ketones, lactams, and peptides, through simple protocols with full recovery of camphor auxiliary, the source of chiral information.
García
Jesús M
JM
Departamento de Química Aplicada, Universidad Pública de Navarra, Pamplona, Spain.
Maestro
Miguel A
MA
Oiarbide
Mikel
M
Odriozola
José M
JM
Razkin
Jesús
J
Palomo
Claudio
C