A Stable Dinuclear Monocationic Gold(I) Complex as Silver-Free Catalyst for Alkyne Hydrofunctionalizations

Gold(I) complexes are particularly useful as catalysts in a variety of reactions including, in particular, the electrophilic activation of alkyne substrates, yet they generally require the addition of a silver salt to activate the gold complex by removing an anionic ligand. This results into higher costs and possible problems related to the non-innocence of the silver additive. In this contribution, we highlight the possibility to proficiently use a dinuclear monocationic gold(I) complex developed in our laboratory as a silver-free catalyst. The complex, featuring a bridging N-phosphanyl-N-heterocyclic carbene (NHCP) ligand, indeed exhibits notable activity and selectivity in standard alkyne hydroamination and hydroalkoxylation reactions, particularly in the case of internal alkynes and secondary aromatic amines as substrates.