Addition of tethered nonaromatic carbon nucleophiles to chemoselectively activated amides.
[reaction: see text] In an effort to develop new ways of synthesizing polycyclic alkaloids, we successfully added silyl enol ethers, allylsilanes, and enamines to iminium ions generated from amides. Because of their higher oxidation state, such iminiums show a yet unexploited advantage of potential double cyclizations over standard Mannich monocyclizations. We report herein the first example of tethered nonaromatic carbon nucleophiles adding to activated amides for the generation of enaminals of various ring sizes, with endo- or exo-cyclic nitrogen.
Bélanger
Guillaume
G
Laboratoire de synthèse organique et de développement de stratégies de synthèse, Département de Chimie, Université de Sherbrooke, 2500 boulevard Université, Sherbrooke, Québec J1K 2R1, Canada. guillaume.belanger@usherbrooke.ca
Larouche-Gauthier
Robin
R
Ménard
Frédéric
F
Nantel
Miguel
M
Barabé
Francis
F
D000577:Amides / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D003500:Cyclization; D004986:Ether / Q000737:chemistry; D007769:Lactams / Q000737:chemistry; D015394:Molecular Structure; D013379:Substrate Specificity
D000577:Amides; D007769:Lactams; D004986:Ether; D002244:Carbon