title: Addition of tethered nonaromatic carbon nucleophiles to chemoselectively activated amides.
abstract: [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.
authors.affiliation: 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
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bélanger
authors.forename: Robin
authors.initials: R
authors.lastname: Larouche-Gauthier
authors.forename: Frédéric
authors.initials: F
authors.lastname: Ménard
authors.forename: Miguel
authors.initials: M
authors.lastname: Nantel
authors.forename: Francis
authors.initials: F
authors.lastname: Barabé
mesh_terms: D000577:Amides / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D003500:Cyclization; D004986:Ether / Q000737:chemistry; D007769:Lactams / Q000737:chemistry; D015394:Molecular Structure; D013379:Substrate Specificity
chemical_list: D000577:Amides; D007769:Lactams; D004986:Ether; D002244:Carbon