Mechanistic Investigation of DBU-Based Ionic Liquids for Aza-Michael Reaction: Mass Spectrometry and DFT Studies of Catalyst Role

1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU)-based ionic liquids (ILs) has exhibited a high catalytic activity in the aza-Michael reactions compared to conventional catalysts and with imidazole-based ILs. In the present work DBU-based ILs showed high catalytic potential for aza-Michael addition of aromatic amines to 2-cyclohexen-1-one under solvent-free condition. Electrospray ionization-mass spectrometry (ESI-MS) and density functional theory studies have been carried out to provide an effective activation mode of DBU-based ILs in aza-Michael addition. Our results show that both the presence of the acid hydrogen in the IL and the ability of the anion to carry out a hydrogen bond with the −NH2 group of the arylamine are fundamental for the reaction catalysis. The catalytic model proposed can be used for the rational development of new ILs with excellent catalytic properties.

Bibliographic Details

Main Authors:	Cândido,Augusto A., Rozada,Thiago C., Rozada,Andrew M. F., Souza,João R. B., Pilau,Eduardo J., Rosa,Fernanda A., Basso,Ernani A., Gauze,Gisele F.
Format:	Digital revista
Language:	English
Published:	Sociedade Brasileira de Química 2020
Online Access:	http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532020000901796
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