1,n-Metal Migrations Mediated by 3d Transition-Metals

Remote functionalization of unactivated sites remains a major challenge in transition-metal-catalyzed synthesis. This Short Review summarizes recent advances in through-space 1,n-metal migration reactions mediated by 3d transition-metals, including Cr, Fe, Co, Ni, and Cu. These transformations enable site-selective bond formation at otherwise inaccessible positions and offer sustainable alternatives to conventional cross-coupling strategies. Mechanistic aspects such as ligand-controlled migration, σ-bond metathesis, isotope-labeling studies, and computational insights are highlighted to illustrate how regio- and stereoselectivity are achieved. Collectively, 3d metalmediated 1,n-migration reactions provide a versatile platform for remote functionalization and open new avenues for reaction design in modern organic synthesis.