The mechanistic role of η2-vinyl complexes in metal-promoted alkyne oligomerisations. The crystal and molecular structures of [W{η5-C(CF3)C(CF3)C(CO2Me )C(CO2Me)C(CF3)C(CF3)SPri}(η5-C5H5)], [WF {η5-C(CF2)C(CF3)C( CO2Me)C( CO2Me)C(CF3)C(CF3)SPri}(η5-C5H5)], and [W{η4-C(CF3)C(CF3)C(Me)C(Me)SPri}(η2-CF3CCCF3)(η5-C5H5)]

Abstract

Reactions of Alkynes RCCR (R = CF₃, CO₂Me, or Me) with η²-vinyl complexes [W{η²-C(CF₃)C(CF₃)SR′}(CF₃CCCF₃)(η⁵-C₅H₅)](R′= Et, Prⁿ, or Prⁱ) give isomeric products [W(CF₃C₂CF₃)₂(RC₂R)SR′(η⁵-C₅H₅)] resulting from insertion of the incomingalkyne into the MC bond of the η²-vinyl and thus illustrate that η²-vinyls can act as intermediates in metal-promoted alkyne oligomerisation reactions.