title: DABCO-based ionic liquids: recyclable catalysts for aza-Michael addition of α,β-unsaturated amides under solvent-free conditions.
abstract: An array of novel 1,4-diazobicyclo[2.2.2]octane (DABCO) based ionic liquids were developed and used as recyclable catalysts for the aza-Michael addition at room temperature without any organic solvent. [DABCO-PDO][OAc] was found to be the most efficient catalyst, and the amount of catalyst was only 10 mol %. Various amines reacted with a wide range of α,β-unsaturated amides, smoothly affording target products in good to excellent yields within hours. Moreover, the catalyst could be reused up to eight times, still maintaining a high catalytic activity. Finally, a plausible mechanism was proposed. FTIR and computational chemistry were used to verify the catalytic mechanism.
authors.affiliation: School of Pharmaceutical and Chemical Engineering, Taizhou University , Taizhou 318000, People's Republic of China.
authors.forename: Anguo
authors.initials: A
authors.lastname: Ying
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Li
authors.forename: Jianguo
authors.initials: J
authors.lastname: Yang
authors.forename: Shuo
authors.initials: S
authors.lastname: Liu
authors.forename: Songlin
authors.initials: S
authors.lastname: Xu
authors.forename: Hua
authors.initials: H
authors.lastname: Yan
authors.forename: Chenglin
authors.initials: C
authors.lastname: Wu