Although tandem reactions offer rapid access to structurally complex molecules in one﹑ot reaction, the selectivity issue needs to be addressed particularly when incompatible step reactions are involved. Herein, we report the selective synthesis of fused N﹉eterocycles from nucleophile‐tethered alkenylamide and carbon monoxide via palladium (Pd)ヽatalyzed tandem carbonylative aza￤acker‐type cyclization. The electronヾeficient nature of amide N〩 and the intramolecular coordination of Pd with alkene accelerate the aminopalladation and effectively prevent the side oxidative carbonylation of diamine moiety to form urea. It is also found that the reported acyl Pd chloride intermediate may not be involved in this tandem cyclization. This work not only provides an efficient synthetic route to fused 1,4ヾiazepanones and 1,4ヾiazepanes but also inspires further development of tandem reactions for the diverse synthesis of heterocycles.