Ruthenium Tris(pyrazolyl)borate Complexes. Part 20 [1]. Synthesis, Characterization, and Reactivity of Neutral Trispyrazolylborate Ruthenium Vinylidene Complexes

Abstract

The reaction of RuTp(COD)Cl (1) with PPh2Pri and terminal alkynes HC≡CR (R=C6H5, C4H3S, C6H4OMe, Fc, C6H4–Fc, C6H9) affords the neutral vinylidene complexes RuTp(PPh2Pri) (Cl)(=C=CHR) (2a–2f) in high yields. These complexes do not react with MeOH to give methoxy carbene complexes of the type RuTp(PPh2Pri)(Cl)(=C(OMe)CH2R), but react with oxygen to yield the CO complex RuTp(PPh2R)(Cl)(CO) (3). The structures of 2b, 2f, and 3 have been determined by X-ray crystallography.