Gold(I) Carbenoids: On‐Demand Access to Gold(I) Carbenes in Solution

Chloromethylgold(I) complexes of phosphine, phosphite, and N‐heterocyclic carbene ligands are easily synthesized by reaction of trimethylsilyldiazomethane with the corresponding gold chloride precursors. Activation of these gold(I) carbenoids with a variety of chloride scavengers promotes reactivity typical of metallocarbenes in solution, namely homocoupling to ethylene, olefin cyclopropanation, and Buchner ring expansion of benzene. Gold in the pocket: Activation of well‐defined gold(I) carbenoids LAuCH2Cl with chloride scavengers promotes reactivity typical of metallocarbenes in solution, namely homocoupling to form ethylene, olefin cycloproanation, and Buchner ring expansion of benzene.