Nano-BF3/cellulose as a biodegradable catalyst for the synthesis of highly functionalized tetrahydropyridines

Tetrahydropyridines (THPs) have been the subject of considerable synthetic efforts because of their potent pharmacological properties including antimalarial [1], andanticancer [2]. Nowadays, chemists prefer to use natural catalysts that can be decomposed in the environment. Cellulose as a biopolymer and biodegradable material can be used as support in preparation of different catalysts. In this work, cotton was chosen as a cheap and readily available source for synthesizing of nano-cellulose [3].Nano-BF3/cellulose is a solid acid and biodegradable catalyst that was prepared via reaction of nano-cellulose and BF3. The structure of this catalyst was studied by FTIR, FESEM, TEM, XRD, EDS, TGA, XRF and BET techniques. In this research, the synthesis of highly functionalized tetrahydropyridines has developed via a five component reaction of aldehyde, amine and ethyl acetoacetate using nano-BF3/cellulose under solvent-free conditions (figure 1). The structures of obtained products were identified by FT-IR, 1H-NMR and 13C-NMR. Some advantages of this protocol are high to good yields, environmentally benign, easy work-up and moderate reusability of the catalyst