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 iso- quinolinedione-type products, which has advantages of simple operation, mild reaction conditions, and environmentally be-