Amberlyst 15®: An Efficient Green Catalyst for the Synthesis of Heterocyclic Compounds

Amberlyst 15 (A-15) is one of the most common heterogeneous catalysts in organic synthesis. Since its development in 1962, A-15 has proved to be a highly efficient green catalyst in many organic reactions that require acid catalysis. In the last two decades, many reports had been issued that focused on the use of A-15 as a catalyst in heterocyclic synthesis. The use of A-15 implies many advantages as being inexpensive, non-toxic, easily handled, and easily separable from the reaction mixture. Other advantages include easy separation of the products and the recyclability. The latter is highly useful in sustainable chemistry. The present review summarizes the applications of Amberlyst 15 as a green catalyst in the synthesis of heterocycles during the last decade (from 2010 till 2019). The review is classified according to the ring size with a focus on the mechanism of reactions catalyzed by A-15.