A new piperidine‐catalyzed Groebke–Bienaymé–Blackburn (GBB) multicomponent reaction of 2‐aminobenzimidazoles, methyl 2‐formylbenzoate, and isocyanides has been explored. A facile and straightforward postmodification leads to isoquinolinone‐embedded imidazo[1,2‐a]benzimidazoles. Insight into a plausible mechanism is discussed and supported by X‐ray crystal structure analysis.