title: Efficient synthesis of substituted 3-azabicyclo[3.1.0]hexan-2-ones from 2-iodocyclopropanecarboxamides using a copper-free Sonogashira coupling.
abstract: The copper-free Sonogashira coupling between N-substituted cis- 2-iodocyclopropanecarboxamides and terminal aryl-, heteroaryl-alkynes or enynes, followed by 5-exo-dig cyclization of the nitrogen amide onto the carbon-carbon triple bond, provides a remarkably efficient access to a variety of substituted 4-methylene-3-azabicyclo[3.1.0]hexan-2-ones in excellent yields. Protonation of these latter enamides generates bicyclic N-acyliminium ions that can be involved in Pictet-Spengler cyclizations leading to new 3-azabicyclo[3.1.0]hexan-2-ones, possessing a quaternary stereocenter at C4, with high diastereoselectivities. This strategy constitutes an attractive complementary alternative to the classical route that relies on the addition of organometallic reagents to cyclopropyl imides.
authors.affiliation: Laboratoire de Chimie Organique, ESPCI ParisTech, CNRS, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: de Carné-Carnavalet
authors.forename: Alexis
authors.initials: A
authors.lastname: Archambeau
authors.forename: Christophe
authors.initials: C
authors.lastname: Meyer
authors.forename: Janine
authors.initials: J
authors.lastname: Cossy
authors.forename: Benoît
authors.initials: B
authors.lastname: Folléas
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Brayer
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Demoute
mesh_terms: D000577:Amides / Q000737:chemistry*; D053961:Azabicyclo Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D060326:Chemistry Techniques, Synthetic / Q000379:methods*; D003500:Cyclization; D003521:Cyclopropanes / Q000737:chemistry*; D006847:Hydrocarbons, Iodinated / Q000737:chemistry*; D015394:Molecular Structure; D054852:Small Molecule Libraries / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000577:Amides; D053961:Azabicyclo Compounds; D003521:Cyclopropanes; D006847:Hydrocarbons, Iodinated; D054852:Small Molecule Libraries