Synthesis of Quinoxaline‐2,3‐diamines via Palladium‐Catalysed Double Isocyanide Insertion Cyclization

An approach for the synthesis of quinoxaline‐2,3‐diamines is reported using a palladium‐catalyzed cyclization reaction of o‐phenylenediamines and isocyanides. Various quinoxaline‐2,3‐diamines could be obtained in 25%‐95% yields at 100 °C for 3 h. The key to the success of this protocol involves the formation of two C‐N and one C‐C bonds via the double insertion of isocyanide.