Facile synthesis of trialkoxymolybdenum(VI) alkylidyne complexes for alkyne metathesis

New molybdenum(VI) alkylidyne complexes (Ar[Pr-i]N)(3)MoCCH2SiMe3 (Ar = 3,5-C6H3Me2) and ((1)AdO)(3)MoCR (R = Me, Et, CH2SiMe3) were obtained in high yield and in multigram quantities starting from a known metallaaziridine-hydride complex. The synthetic protocol involves treatment with Me3SiCCH, heating, and ligand exchange via alcoholysis; ((1)AdO)(3)MoCCH2-SiMe3 is an active catalyst for alkyne metathesis at room temperature.