Synthesis of Polysubstituted Maleimides via Metal-Free Cascade Reaction of Isocyanides and α‑Diazoketones

In this paper, synthesis of polysubstituted maleimides was described via cascade reaction of isocyanides and α-diazoketones. This strategy features readily available substrates, high atom-economy and metal-free conditions. A variety of valuable polysubstituted maleimides are assembled in good yields.