Consecutive C-C bond scission of an allyl ligand on a WOs3 cluster framework

Article abstract of DOI:10.1021/om00021a004

The reaction of Os₃(CO)₉(C₂R₂) (R = Tol, Ph; Tol = p-C₆H₄Me) with Cp(CO)₂W≡CTol (Cp = η⁵-C₅H₅) produces an alkylidyne-alkyne complex CpWOs₃(CO)₁₀(μ₃-??²-C ₂R₂)(μ₃-CTol) [1a (R = Tol), 1b (R = Ph)], which is converted to two isomeric allyl complexes CpWOs₃(CO)₁₀(μ₃-η³-C ₃R₂Tol) (2a,b and 3a,b) upon thermolysis. Complexes 3a,b, in which the allyl ligand is π-coordinated to the tungsten atom, undergo consecutive allyl C-C bond cleavage to afford trialkylidyne complexes CpWOs₃(CO)₉(μ₃-CR)₂(μ ₃-CTol) (5a,b) via alkylidyne-alkyne complex CpWOs₃(CO)₁₀(μ₃-η²-C ₂R₂)(μ₃-CTol) or CpWOs₃(CO)₁₀(μ₃-η³-C ₂RTol)(μ₃-CR) (4a,b), together with formation of CpWOs₃(CO)₈(μ₃-η ²-⊥-C₂R₂)(μ₃-CTol) or CpWOs₃(CO)₈(μ₃-η ²-⊥-C₂RTol)(μ₃-CR) (6a,b) as a minor product.