Mechanistic Insights into the Selective Synthesis of 4<i>H</i>-Pyran Derivatives On-Water Using Naturally Occurring Alginate from <i>Sargassum muticum:</i> Experimental and DFT Study
Khaoula Oudghiri,
Zahira Belattmania,
Hamid Elmouli,
Salaheddine Guesmi,
Fouad Bentiss,
Brahim Sabour,
Lahoucine Bahsis,
Moha Taourirte
Affiliations
Khaoula Oudghiri
Laboratoire de Recherche en Développement Durable et Santé, Faculté des Sciences et Techniques de Marrakech, Université Cadi Ayyad, Marrakech 40000, Morocco
Zahira Belattmania
Laboratory of Plant Biotechnology, Ecology and Ecosystem Valorization—URL CNRST N=10, Faculty of Sciences El Jadida, University Chouaib Doukkali, P.O. Box 20, El Jadida 24000, Morocco
Hamid Elmouli
Laboratoire de Chimie de Coordination et d’Analytique (LCCA), Département de Chimie, Faculté des Sciences, Université Chouaïb Doukkali, P.O. Box 20, El Jadida 24000, Morocco
Salaheddine Guesmi
Laboratoire de Chimie de Coordination et d’Analytique (LCCA), Département de Chimie, Faculté des Sciences, Université Chouaïb Doukkali, P.O. Box 20, El Jadida 24000, Morocco
Fouad Bentiss
Laboratory of Catalysis and Corrosion of Materials, Faculty of Sciences, University Chouaib Doukkali, P.O. Box 20, El Jadida 24000, Morocco
Brahim Sabour
Laboratory of Plant Biotechnology, Ecology and Ecosystem Valorization—URL CNRST N=10, Faculty of Sciences El Jadida, University Chouaib Doukkali, P.O. Box 20, El Jadida 24000, Morocco
Lahoucine Bahsis
Laboratoire de Chimie de Coordination et d’Analytique (LCCA), Département de Chimie, Faculté des Sciences, Université Chouaïb Doukkali, P.O. Box 20, El Jadida 24000, Morocco
Moha Taourirte
Laboratoire de Recherche en Développement Durable et Santé, Faculté des Sciences et Techniques de Marrakech, Université Cadi Ayyad, Marrakech 40000, Morocco
The naturally occurring sodium alginate (SA) biopolymer from the Sargassum muticum (Yendo) Fensholt was employed as a green organocatalyst for the synthesis of 4H-pyran derivatives. The naturally extracted macromolecule was fully characterized using different analyses, including nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Energy Dispersive X-ray Analysis (EDX). The catalytic activity of SA was investigated in the one-pot reaction between aldehydes, malononitrile, and 1,3-dicarbonyl compounds in water at room temperature, and the corresponding 2-amino-3-cyano-4H-pyran derivatives were obtained with good to excellent yields. This organocatalyst was easily separated from the reaction mixture and reused for at least two consecutive cycles without a significant loss of its catalytic activity or selectivity. From the mechanistic point of view, density functional theory (DFT) and NCI analyses were performed for the first time to explain the regioselectivity outcomes for the synthesis of 2-amino-3-cyano-4H-pyran derivatives using SA as a green organocatalyst.
