Nickel‐Catalyzed Regio‐ and Stereoselective Three‐Component Difunctionalization of Alkynes

Nickel‐catalyzed three‐component difunctionalization of alkynes has emerged as a powerful strategy for the rapid construction of complex molecular architectures with high step and atom economy. This review systematically summarizes recent advances in alkyne difunctionalizations and categorizes them into two sections based on different catalytic modes: single nickel catalysis and photoredox/nickel dual catalysis. The single nickel catalysis exploits the intrinsic redox versatility of nickel in combination with judicious ligand design to afford high levels of regio‐ and stereocontrol and broad functional‐group tolerance. In contrast, the photoredox/nickel dual catalytic system merges visible‐light‐driven single‐electron transfer with nickel–mediated bond formation, enabling otherwise challenging radical‐type difunctionalizations under mild, room‐temperature conditions and without external reductants. The mechanistic features, substrate scope, and representative examples of each paradigm are critically discussed, with emphasis on their distinct advantages and complementarity. Finally, current limitations and prospects for future development are outlined.