Four recoverable and reusable ionic liquids based on 1,4-diazobicyclo[2.2.2]octane（DABCO） have been synthesized to catalyze the aza-Michael addition of secondary amines to a,b-unsaturated compounds.Among the catalys...Four recoverable and reusable ionic liquids based on 1,4-diazobicyclo[2.2.2]octane（DABCO） have been synthesized to catalyze the aza-Michael addition of secondary amines to a,b-unsaturated compounds.Among the catalysts tested,[DABCO-PDO][OAc] was found to be most suitable for the reaction of a wide range of cyclic substrates without any solvent at room temperature,and afford the products in good to excellent yields within an appropriate amount of time.The proposed mechanism for the dual activation of the catalyst was supported by experimental results as well as the DFT calculation.In addition,the ionic liquids used can be regenerated and recycled several times without any loss of activity.展开更多
基金the National Natural Science Foundation of China (Nos.21106090 and 21176170)Foundation of Low Carbon Fatty Amine Engineering Research Center of Zhejiang Province (No.2012E10033)Zhejiang Provincial Natural Science Foundation of China (No.LY12B02004)
文摘Four recoverable and reusable ionic liquids based on 1,4-diazobicyclo[2.2.2]octane（DABCO） have been synthesized to catalyze the aza-Michael addition of secondary amines to a,b-unsaturated compounds.Among the catalysts tested,[DABCO-PDO][OAc] was found to be most suitable for the reaction of a wide range of cyclic substrates without any solvent at room temperature,and afford the products in good to excellent yields within an appropriate amount of time.The proposed mechanism for the dual activation of the catalyst was supported by experimental results as well as the DFT calculation.In addition,the ionic liquids used can be regenerated and recycled several times without any loss of activity.
