Isolation of a Non‐Heteroatom‐Stabilized Gold–Carbene Complex

Gold–carbene complexes are essential intermediates in many gold‐catalyzed organic‐synthetic transformations. While gold–carbene complexes with direct, vinylogous, or phenylogous heteroatom substitution have been synthesized and characterized, the observation in the condensed phase of electronically non‐stabilized gold–carbenes has so far remained elusive. The sterically extremely shielded, emerald‐green complex IPr**Au=CMes₂]⁺NTf₂]^? has now been synthesized, isolated, and fully characterized. Its absorption maximum at 642 nm, in contrast to 528 nm of the red‐purple carbocation Mes₂CH]⁺, clearly demonstrates that gold is more than just a “soft proton”.