A review on innovative approaches in quinoline/isoquinoline synthesis: Unveiling the Pummerer reaction strategy

The Pummerer rearrangement is extensively utilized for the preparation of various heterocyclic compounds, as well as for the introduction of functional groups such as carbonyl, hydroxyl, and amino groups into organic molecules. The reaction mechanism typically proceeds through an initial electrophilic attack by Lewis acid or another electrophile on the sulfur atom of the sulfoxide, leading to the formation of a sulfonium intermediate. Subsequent rearrangement of this intermediate results in the migration of an alkyl/aryl group from sulfur to a neighboring carbon atom, accompanied by the expulsion of a leaving group. The Pummerer rearrangement of quinoline derivatives has significant synthetic utility and has been employed in the synthesis of various compounds. It has found applications in the synthesis of natural products, agrochemicals, pharmaceuticals, diversity-oriented synthesis, functional group transformations, and other fine chemicals. Overall, The Pummerer rearrangement of quinoline derivatives offers a versatile tool for the synthesis of complex molecules in medicinal chemistry.