Abstract

The novel activation model of multifunction thiourea organocatalysts is examined using density functional theory calculations. The key feature of this model is that the two N-H of thiourea group play different roles in activating substrates, one N-H activates cyclohexenone, and the other N-H and tertiary amine of epiquinine activate the hydroxyl of diphenylphosphine oxide together. More importantly, there is a hydrogen bond between one hydrogen atom in primary amine of catalyst with phenyl ring of diphenylphosphine oxide via a NH-π interaction.

Keywords: Activation model, DFT, H-bonding activation, organocatalysts, theoretical calculations, thiourea.