Experimental and DFT studies on the green synthesis of 2-amino-4H-chromenes using a recyclable GOQDs-NS-doped catalyst

Parvin Beigiazaraghbelagh; Shahnaz Rostamizadeh; Ahmad Poursattar Marjani; Aidin Bahrami; Arezu Ghiasvand; Zahra Arabi

doi:10.1038/s41598-024-82347-1

Experimental and DFT studies on the green synthesis of 2-amino-4H-chromenes using a recyclable GOQDs-NS-doped catalyst

Sci Rep. 2024 Dec 30;14(1):31737. doi: 10.1038/s41598-024-82347-1.

Authors

Parvin Beigiazaraghbelagh¹, Shahnaz Rostamizadeh², Ahmad Poursattar Marjani³, Aidin Bahrami⁴, Arezu Ghiasvand², Zahra Arabi²

Affiliations

¹ Department of Chemistry, Faculty of Science, K. N. Toosi University of Technology, P.O. Box 15875-4416, Tehran, Iran. beigiazarp@yahoo.com.
² Department of Chemistry, Faculty of Science, K. N. Toosi University of Technology, P.O. Box 15875-4416, Tehran, Iran.
³ Department of Organic Chemistry, Faculty of Chemistry, Urmia University, Urmia, Iran.
⁴ Department of Physical Chemistry, Faculty of Chemistry, Urmia University, Urmia, Iran.

Abstract

This research presents an innovative approach for synthesizing 2-amino-4H-chromene derivatives, utilizing 30 mg of NS-doped graphene oxide quantum dots (GOQDs) as a catalyst in a one-pot, three-component reaction conducted in ethanol. The NS-doped GOQDs were synthesized using a cost-effective bottom-up method through the condensation of citric acid (CA) with thiourea and the reaction was carried out at 185 $^{\circ}$ C, resulting in the elimination of water. The catalytic performance of the synthesized NS-doped GOQDs resulted in high product yields, achieving up to 98% for the 2-amino-4H-chromene derivatives from aromatic aldehydes, malononitrile, resorcinol, $β$ -naphthol, and dimedone. The reaction showcased rapid completion time (typically < 2 h), low-cost reagents, and easy work-up procedures. In addition, the study integrates experimental and theoretical analyses, including density functional theory (DFT) calculations, to investigate the electronic properties of the synthesized compounds. Calculated HOMO and LUMO energies indicate efficient charge transfer within the molecular structure. The FT-IR spectra of compound 4c were recorded in the range of 4000-500 cm $^{- 1}$ , and vibrational frequencies were computed at the B3LYP/6-311+G(d,p) level, correlating well with experimental data. Detailed analyses, including Mep surfaces, Mulliken population analysis, and Natural Bond Orbital (NBO) analysis, provide further insights into the electronic distribution and reactivity of the compounds. Furthermore, comparative $^{1}$ H and $^{13}$ C NMR analyses of compound 4c reveal strong agreement between computational and experimental findings. This research not only validates the synthetic method but also emphasizes the dual experimental and computational approach in understanding the structural and electronic characteristics of the 4c compound.

Keywords: B3LYP/6-311+G(d; Chromene; Electrophilicity index; Graphene oxide; Multi-component reaction; NBO analysis; p).