Supramolecular β-Cyclodextrin as a Reusable Catalyst for Xanthene Synthesis in Aqueous Medium.

In green chemistry, the most notable objectives include atom economy, the use of non-hazardous catalysts and solvents, and the reduction of by-products, energy costs, and waste. Initially, the reaction between I i -naphthol (2.0 mmol) and benzaldehyde (1.0 mmol) for the preparation of B 5e b was studied in various solvents and temperatures in the presence of different concentrations of supramolecular I i -cyclodextrin. In this context we now report the use of supramolecular I i -cyclodextrin in the synthesis of 12-aryl-tetrahydrobenzo[ I i ]xanthene-11-ones and 14-aryl-14 I H i -dibenzo[ I ,j i ]xanthenes in an aqueous medium. 14-Aryl-14H-dibenzo[ ,j]xanthenes derivatives (5) A mixture of I i -naphthol ( B 1 b , 2.0 mmol), the appropriate aromatic aldehyde ( B 2 b , 1.0 mmol), I i -CD (15 mol %) and 5 mL H SB 2 sb O was reacted at 80 °C (Scheme 2). [Extracted from the article]