A magnetic solid sulfonic acid modified with hydrophobic regulators: an efficient recyclable heterogeneous catalyst for one-pot aza-Michael-type and Mannich-type reactions of aldehydes, ketones, and amines

A review on convenient synthesis of substituted coumarins using reuseable solid acid catalysts

Due to growing concern about chemicals and their impact on the environment, cleaner reaction conditions are needed to be incorporated into chemical synthetic procedures. Recently, the use of heteropolyacid catalysts, mainly reuseable solid acid catalysts, has gained a leading role in organic synthesis due to their environmental and economic considerations and industrial utilization. The high catalytic activity, moisture sensitivity, reusability and inexpensive makes solid supported reagents attractive substituents to conventional Lewis acids. Nowadays synthesis of coumarins and their derivatives has attracted considerable attention from organic and medicinal chemists for many years as a large number of natural products contain this heterocyclic nucleus. In continuation with our investigations into the synthesis of substituted coumarins and due to several advantages of heterogeneous catalysts viz. cost-effective, no side products, high yield of desired products and no toxic waste material, here we report a new approach for the synthesis of substituted coumarins using solid acid catalysts.

Novel synthesis of coumarin-containing secondary benzamide derivatives using tungstate sulfuric acid

A novel one-pot synthesis of coumarin-containing secondary benzamide derivatives is described using tungstate sulfuric acid as a reusable heterogeneous catalyst.