Combining commercially available bromoanilines and bromobenzonitriles in a novel double carbonylation process allows for a straightforward synthesis of isoindolo[1,2‐b]quinazoline‐10,12‐diones. At least five different CC and/or CN bonds are selectively formed in this 3‐component reaction, which likely proceeds through sequential carbonylation–cyclization–isomerisation–carbonylation steps. Notably