Michael I. Bruce, Peter Hinterding, Paul J. Low, Brian W. Skelton and Allan H. White
The reaction of buta-1,3-diyne with [Ru(thf)(PPh3)2(η-C5H5)]+ (thf = tetrahydrofuran) to give [Ru(C
C
C
CH2)(PPh3)2(η-C5H5)]+ has been studied. This complex adds nucleophiles at Cγ, as expected from theory and consideration of the protection afforded to Cα by the bulky PPh3 ligands. The products were alkenylethynyl complexes (from aprotic nucleophiles) or methylallenylidene complexes (from protic nucleophiles, with H migration to Cδ). With water, the complex [Ru{C
CC(O)Me}(PPh3)2(η-C5H5)] is formed. The single-crystal structures of [Ru{C
C
CMe(X)}(PPh3)2(η-C5H5)][PF6] (X = NPh2 or C4H3NMe-2) and [Ru(C
CCH
CHCl-trans)(PPh3)2(η-C5H5)] have been determined.