title: Copper-catalyzed synthesis of azaspirocyclohexadienones from alpha-azido-N-arylamides under an oxygen atmosphere.
abstract: A copper-catalyzed reaction of alpha-azido-N-arylamides was found to proceed under an oxygen atmosphere to afford azaspirocyclohexadienones. The present transformation is carried out by a sequence of denitrogenative formation of iminyl copper species from alpha-azido-N-arylamides and their imino-cupration with an intramolecular benzene ring on the amido nitrogen followed by consecutive formation of C=O bonds. The preliminary investigation revealed that molecular oxygen is a prerequisite for achieving the present catalytic cyclization and that one of the oxygen atoms of O(2) was found to be incorporated into the cyclohexadienone moiety.
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore. shunsuke@ntu.edu.sg
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Chiba
authors.forename: Line
authors.initials: L
authors.lastname: Zhang
authors.forename: Jian-Yuan
authors.initials: JY
authors.lastname: Lee
mesh_terms: D000577:Amides / Q000737:chemistry*; D001372:Aza Compounds / Q000138:chemical synthesis*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D003500:Cyclization; D053138:Cyclohexenes / Q000138:chemical synthesis*; D010100:Oxygen / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis*
chemical_list: D000577:Amides; D001372:Aza Compounds; D053138:Cyclohexenes; D013141:Spiro Compounds; C507608:cyclohexadienone; D003300:Copper; D010100:Oxygen