Regioselective Dimetallapolycarbyl Hydrometalation

The reactions of [L(CO)2W⋮CC⋮CC⋮CC⋮W(CO)2L] (L = HB(pz)3, HB(pz‘)3; pz = pyrazol-1-yl, pz‘ = 3,5-dimethylpyrazol-1-yl) with [RuHCl(CO)(PPh3)3] result in regioselective hydroruthenation of one C⋮C bond of the WC6W spine to provide the coordinatively unsaturated hex-2-en-4-yn-3-yl-1,6-diylidyne-bridged complex [Ru{C(C⋮CC⋮W(CO)2L)CHC⋮W(CO)2L}Cl(CO)(PPh3)2].