Beyond the Lindlar catalyst: highly-oxidized Pd single atoms as promoters for alkyne semi-hydrogenation

A “grafting-then-coordination” strategy was proposed to construct Pd/C-NH 2 featuring coexisting tetravalent Pd single atoms (Pd IV SAs) and Pd nanoparticles (Pd NPs), which achieves inhibitor-free, highly efficient hydrogenation of steroidal alkynes.