Snail shell as a new natural and reusable catalyst for synthesis of 4H-Pyrans derivatives

Abstract

A simple, efficient and general method for the synthesis of 4H-pyrans is established through a multi component cyclocondensation of aromatic aldehydes, malononitrile and ethyl acetoacetate or acetyl acetone using snail shell as a natural catalyst. In this method the snail shell was used as green and reusable natural catalyst. Excellent yields, short reaction times and availability of the catalyst are the advantages of this method.

Zn(L-proline)2: An efficient and reusable organocatalyst for the synthesis of polyfunctionally substituted pyrans and 2-amino-4-aryl-8-oxo-4,8-dihydropyrano[3,2-b]pyran derivatives

“…Extensive efforts have been developed for the adaption of environmentally techniques in heterocyclic synthesis. Hence the development of a green synthetic protocol remains a challenge [19,20]. One such protocol involves the use of cheap, recyclable and easy handle catalyst.…”

Comparative study between the Titanium Phosphate TiP2O7 and the Phosphate Fertilizers in the catalysis of the Quinazolin-4(3H)-one derivatives synthesis

“…As a continuation of the previous works developed by our researchers [27][28][29][30][31][32][33][34][35][36][37][38][39] , which consist on the valorization of Moroccan phosphates in the field of organic synthesis, and the development of green and sustainable chemistry, this paper reports the first and an easy preparation method for TiP2O7 from the modifications of phosphate fertilizers MAP, DAP and TSP by titanium tetrachloride (TiCl4). The characterization of TiP2O7 was realized using spectroscopic and microscopic technics such as XRD, IR, SEM, and EDX.…”

Waste-to-wealth transition: application of natural waste materials as sustainable catalysts in multicomponent reactions

“…The structure of SS was established by XRD, BET, and SEM; the average specific surface obtained by BET analysis was about 3.15 m 2 g −1 . 67…”

“…The structure of SS was established by XRD, BET, and SEM; the average specific surface obtained by BET analysis was about 3.15 m 2 g −1 . 67 In 2019, Benzekri et al studied the catalyst activity of snail shells in the synthesis of 1,4-dihydropyrano[2,3-c]pyrazoles 19 through the reaction of aldehydes 1, ethyl acetoacetate 13, malononitrile 10, and hydrazine 18 (Scheme 13). 68 In 2021, Benzekri and co-workers reported snail shell waste as a catalyst to prepare 1-(benzothiazolylamino) methyl-2naphthols derivatives 23 via the reaction of aromatic aldehydes 1,2-aminobenzothiazole 21, and β-naphthol 22 (Scheme 14).…”