Natural deep eutectic solvents (NADESs) have emerged as a novel class of solvents with properties reminiscent of ionic liquids while offering additional advantages in terms of cost, environmental impact, and synthesis. This article focuses on the applications of NADESs of mannose:urea and glucose:dimethylurea as inexpensive, accessible, and reusable catalysts in the synthesis of dihydropyrimidinone and polyhydroquinoline derivatives. The results demonstrate significant yields for both dihydropyrimidinones (47–99%) and polyhydroquinolines (90–97%) reactions using mannose:urea and glucose:dimethylurea as catalysts. The advantages of NADESs as catalysts include their simple and reproducible preparation, low cost, environmentally benign nature, long-term durability, and tunable properties. This NADESs can also be recovered and reused for four times without a significant loss of activity.
