Tetrabutylammonium Iodide-Catalyzed Radical Alkoxycarbonylation of Activated Alkenes: Synthesis of Isoquinolinedione Derivatives

The isoquinolinedione skeletons are important building blocks, which have been widely present in plant alkaloids, natural products and pharmaceuticals.In this paper, a novel method to construct isoquinolinedione framework was developed, which can be easily operated under metal-free conditions.In the presence of tetrabutylammonium-iodide catalyst, hydrogen atoms were abstracted step by step from carbazate to generate methoxycarbonyl radical which followed by radical addition/ cyclization reaction leading to isoquinolinedione.The presented methodology will provide new strategies for construct isoquinolinedione-type products, which has advantages of simple operation, mild reaction conditions, and environmentally benign.