Multidentate Triphenolsilane‐Based Alkyne Metathesis Catalysts

Abstract A series of triphenolsilane‐coordinated molybdenum(VI) propylidyne catalysts has been developed, which are resistant to small alkyne polymerization and compatible with various functional groups (including phenol substrates). The catalysts remain active in solution for days at room temperature (months at −30 °C). The catalysts are also compatible with 5 Å molecular sieves (small alkyne scavengers), and have enabled the homodimerization of small alkyne substrates at 40–70 °C in a closed system, with dimer products being obtained in 76–96% yields. A shape‐persistent aryleneethynylene macrocycle ( 11 ) was also prepared on a gram scale with 0.5 mol% catalyst loading, in almost quantitative yield.