Influence of Ylide Functionalization on the Catalytic Performance of Ferrocenyldiphosphines in Au(I)‐Catalyzed Hydroaminations and Hydrohydrazinations

Ylide‐functionalized phosphines (YPhos) have been shown to yield highly active gold catalysts owing to their high donor capacity. To examine the impact of ylide functionalization on a given ligand structure, a series of ferrocenyl diphosphines functionalized with no, one or two ylide moieties and their corresponding bimetallic gold complexes were prepared. The complexes feature an anti‐conformation of the two phosphine moieties, guaranteeing the presence of two independent metal centers. Comparative studies of the complexes in the hydroamination and hydrohydrazination of alkynes revealed a significant increase in catalytic activity for each newly introduced ylide group. The di‐YPhos ligands were revealed to be the most active precatalysts, functioning effectively even at 0.1 or 0.2 mol % catalyst loading. This catalytic efficiency was demonstrated for a series of alkynes, amines and hydrazines. The catalytic performance of a series of gold complexes based on ferrocenyldiphosphines with or without ylide substituents was compared in the hydroamination and hydrohydrazination of alkynes. Each introduction of a ylide group resulted in a significant increase in activity, resulting in highly active catalysts for a variety of substrates.