Ethylenediamine attached to silica as an efficient, reusable nanocatalyst for the addition of nitromethane to cyclopentenone

A solid base nanocatalyst was obtained by co-condensation between tetraethylorthosilicate (TEOS) and 3-glycidoxypropyltrimethoxysilane around a neutral n-dodecylamine template. The glycidoxy ring was opened by reaction with ethylenediamine, to give the desired Caten nanocatalyst. Thermogravimetric analysis showed that the number of active basic groups in this nanocatalyst is 1.22 mmol g−1. Its TEM image showed that its individual particle is spherical, with a size of approximately 50 nm. Nitrogen adsorption–desorption isotherms gave evidence that this nanocatalyst has a mesoporous structure with pore diameter and surface area of 5.2 nm and 796.1 m2 g−1, respectively. Analyses by 13C and 29Si nuclei NMR confirmed the obtention of the catalyst proposed in the synthetic route. The obtained material was used as catalyst in the addition of nitromethane to cyclopentenone in equimolar amounts, and yields of nitromethylcyclopentanone as high as 98% were achieved after only 30 min of reaction. It was possible to recover the catalyst from the reaction medium and recycle it 10 times.

Graphical abstractSolid base nanocatalyst was developed and was applied and reused in the addition of nitromethane to cyclopentenone in equimolar conditions. Figure optionsDownload full-size imageDownload as PowerPoint slide