title: Synthesis of medium ring nitrogen heterocycles via a tandem copper-catalyzed C-N bond formation-ring-expansion process.
abstract: A simple method for the preparation of medium ring heterocycles (7-, 8-, 9-, and 10-membered) has been developed. The process employs a Cu-catalyzed coupling of a beta-lactam with an aryl bromide or iodide followed by intramolecular attack of a pendant amino group. In some instances, the intermediate beta-lactam is observable but can be converted to the aza-heterocycle by catalysis. Acetic acid was found to be superior to transition metal complexes as a catalyst for this ring-expansion process.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Artis
authors.initials: A
authors.lastname: Klapars
authors.forename: Sean
authors.initials: S
authors.lastname: Parris
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Anderson
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Buchwald
mesh_terms: D000588:Amines / Q000138:chemical synthesis*; D001555:Benzene Derivatives / Q000138:chemical synthesis; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D003500:Cyclization; D006574:Heterocyclic Compounds, 2-Ring / Q000138:chemical synthesis*; D007769:Lactams / Q000138:chemical synthesis*
chemical_list: D000588:Amines; D001555:Benzene Derivatives; D006574:Heterocyclic Compounds, 2-Ring; D007769:Lactams; D003300:Copper