title: N-Methyl Transfer Induced Copper-Mediated Oxidative Diamination of Alkynes.
abstract: A novel intramolecular oxidative diamination of bis(2-aminophenyl)acetylene for the synthesis of the structurally intriguing π-conjugated polyheterocyclic scaffold, 5,10-dihydroindolo[3,2-b]indole (DHII), has been developed under Cu(hfacac)2/O2 oxidation systems. The structure design of bis(2-aminophenyl)acetylene bearing both N,N-dimethylamine and primary amine groups is crucial for constructing the corresponding DHII scaffold. Notably, an intermolecular N-methyl transfer from the nitrogen atom of N,N-dimethylamine to the primary amine takes place, which is a critical step for the successful implementation of the present annulation process.
authors.affiliation: WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University , Sendai, 980-8577, Japan.
authors.forename: Hon Eong
authors.initials: HE
authors.lastname: Ho
authors.affiliation: WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University , Sendai, 980-8577, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Oniwa
authors.affiliation: WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University , Sendai, 980-8577, Japan.|State Key Laboratory of Fine Chemicals, Dalian University of Technology , Dalian, 116012, China.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University , Sendai, 980-8577, Japan.
authors.forename: Tienan
authors.initials: T
authors.lastname: Jin