Advances in Transition‐Metal‐Catalyzed 1,2‐N‐Migrations via Carbon‐Centered Carbenes and Radicals

1,2‐N‐migrations onto metal carbenes and carbon radicals have been substantially applied as a guiding strategy in structurally complex nitrogen‐containing molecules and diverse nitrogen heterocycles. This strategy can construct structural complexity through a molecular skeletal recombination due to the fact that this type of reaction involves the carbon–nitrogen bond cleavage and formation between three adjacent atoms. In recent years, the field of 1,2‐N‐migrations onto metal carbenes and carbon radicals has experienced rapid development and a range of efficient synthetic protocols have been documented. In this review, we will focus on the recent progress in the 1,2‐N‐migrations onto metal carbenes as well as carbon radicals and the mechanistic research is showcased where possible.