Chitosan is a biopolymer that is found in nature and is produced from chitin deacetylation. Chitosan has been studied thoroughly for multiple applications with an interdisciplinary approach. Antifungal antibacterial activities, mucoadhesion, non-toxicity, biodegradability, and biocompatibility are some of the unique characteristics of chitosan-based biomaterials. Moreover, chitosan is the only widely-used natural polysaccharide, and it is possible to chemically modify it for different applications and functions. In various fields, chitosan composite and compound manufacturing has acquired much interest in developing several promising products. Chitosan and its derivatives have gained attention universally in biomedical and pharmaceutical industries as a result of their desired characteristics. In the present mini-review, novel methods for preparing chitosan-containing materials for dental and implant engineering applications along with challenges and future perspectives are discussed.

The catalytic property of Cu(II) Schiff-base complex in an efficient synthesis of 1,8-dioxodecahydroacridines was investigated. The one-pot three component reaction of dimedone, aromatic aldehydes and aromatic amines or ammonium acetate in water afforded the corresponding 1,8-dioxodecahydroacridines with excellent yields. This reaction was carried out in the presence of 1 mol% of catalysts at room temperature. The reusability of the catalysts was demonstrated by a five-run test without loss of its activity. Also, this catalyst possesses several advantages including mild reaction conditions, lower catalytic loading, shorter reaction times, high yield of the products, inexpensive and cleaner (Green chemistry) reactions.

Recyclable SnO₂ nanoparticles catalyze the Pechmann condensation between phenolic alcohols and β-ketoesters at room temperature in ethanol leading to coumarins. Also, in another study the synthesis of biscoumarins catalyzed by SnO₂ nanoparticles in the reaction between 4-hydroxycoumarin and aldehydes under same condition reactions. The corresponding coumarins and biscoumarins were produced efficiently with facility and excellent yields (93–98%). These approaches display the advantages of benign reaction conditions, non-chromatographic purification procedure, appropriate functional group tolerance and valuable process.

1-Amidoalkyl-2-naphthol derivatives have been synthesized via solvent-free three-component reac­tion between various aldehydes, β-naphthol, and urea or benzamide by using 2 mol % of Ag-TiO₂ nanocomposite as an efficient benign heterogeneous catalyst at 110°C. The catalyst was easily recycled and reused up to three times without significant loss in activity. The proposed method provides significant benefits, including benign conditions, atom economy, low amount of the catalyst, the use of low-cost, accessible, and recyclable nanocom­posite catalyst, and no need of chromatographic purification of the target products.

The three component condensation reaction of aldehydes with dimedone and ammonium acetate or anilines happened in the presence of Ag nanoparticles as a heterogeneous catalyst at room temperature in ethanol.Ag nanoparticles can suitably be handled and removed from the reaction mixture, generating the experimental process simple and green.The significant features of this method are suitable conversions, cleaner reaction profiles and short reaction time. The catalyst is recycled and reused for five successive times without loss of structure and significant activity.