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Please login to access the full content or check if you have access via Variation 2: Ruthenium-Catalyzed Cycloisomerization To Give Vinylcycloalkenes

DOI: 10.1055/sos-SD-046-00090

Gandon, V.; Thorimbert, S.; Malacria, M.Science of Synthesis, (200946220.

In 1994 the use of various ruthenium complexes {[{RuCl2(CO)3}2], [Ru3(CO)12], [Ru(Cp)Cl(PPh3)2], [Ru2Cl4(p-cymene)2], RuCl3, etc.} was described for the cycloisomerization of 1,6- or 1,7-enynes 162 [X=C(Me)2, C(CO2Me)2] into the corresponding vinylcyclopentenes or vinylcyclohexenes 163 (Scheme 57).[‌152‌] In the early work the best precatalyst, tricarbonyldichlororuthenium(II) dimer, was shown to work well with enynes having a terminal alkyne unit, but the mechanism of this cycloisomerization[‌153‌] may be different from that which employs a palladium species (Section Indeed, it was originally considered that both halide and carbon monoxide ligands bonded to ruthenium were essential for catalytic activity, and it was only demonstrated later that halide is unnecessary if a phosphine ligand is present.[‌154‌,‌155‌]

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