An efficient three-component reaction of indole, aldehyde, and malononitrile in water catalyzed by a copper(II) sulfonato Salen complex afforded 3-indole derivatives in good to excellent yields up to 97%.
A ligand-free copper(II)-catalyzed three-component reaction in poly(ethylene glycol) medium: a versatile protocol for the preparation of selected 3-indole derivatives
aldehydes, and malononitrile in polyethylene glycol. The reagent system (PEG solvent plus catalyst) could be recycled up to 5 times for reaction with the same aldehyde and it was used also with at least three different aldehydes successively. This multi-component reaction (MCR) occurs first through Knoevenagel condensation followed by Michael addition of indole.
Polyethylene glycol (PEG-200)-promoted sustainable one-pot three-component synthesis of 3-indole derivatives in water
作者:Leilei Wang、Manna Huang、Xinhai Zhu、Yiqian Wan
DOI:10.1016/j.apcata.2012.12.008
日期:2013.3
A sustainable three-component reaction of indoles, aldehydes, and malononitrile in water promoted by polyethyleneglycol (PEG-200) afforded 3-indole derivatives in good to excellent yields.
Water Assisted and Choline Chloride-Dimethylurea Deep Eutectic Salts as Catalyst towards the Attractive Reaction of Indole, Benzaldehyde, and Malononitrile
The condensation of indole, benzaldehyde, and malononitrile was relatively rigorous compared with other Yonemitsu type reaction. We described a strategy using catalytic amount of choline chloride-dimethylurea deep eutectic salts as cheap and safe accelerator. We also found that introducing right amount of water in reaction system was crucial. This method tolerates variations in all three components to get desired 3-substituted indoles in satisfactory yields.