The magical but endangered metal: searching for sustainable palladium catalysis

This review highlights recent strategies to make palladium-catalyzed reactions more sustainable. The use of micellar reaction media, strategically designed ligands, and alternative photocatalytic pathways have enabled recycling and dramatically lowered or completely eliminated palladium in important catalytic processes. Recent developments in the use of ppm levels of palladium in conjunction with earth-abundant metals are also reviewed, including use as a nanoparticle dopant and as a trace co-catalyst.