Designing a Green Replacement for the Lindlar Catalyst for Alkyne Semi-hydrogenation Using Silica-Supported Nickel Nanoparticles Modified by N-Doped Carbon

A lead- and palladium-free alternative to the Lindlar catalyst has been developed for industrially relevant alkyne semi-hydrogenation using silica-supported nickel nanopartides modified by nitrogen-doped carbon. The optimal nickel catalyst acts under mild conditions (5 bar H-2, 100 degrees C, and 4 h) for the selective semi-hydrogenation of a range of allcynes, including vitamin precursors that are important food supplements. Notably, this novel catalyst is selective for alkynes in the presence of easily reducible groups such as carbonyl and nitrile, which also makes it attractive for other synthetic applications.