Hydration of Nitrosylruthenium Acetylide Complexes Having a Tris(pyrazol-1-yl)borate in the Presence of Protic Acid:  Formation of Ketonyl and Acyl Complexes

Treatment of the monoacetylide complexes TpRuCl(C⋮CR)(NO) (R = Ph (1a), p-CH₃C₆H₄ (1b), ^tBu (1c), CH₂CH₂OH (1d), CH₂OH (1e), C(Me)₂OH (1f), C(Ph)₂OH (1g); Tp = BH(pyrazol-1-yl)₃) with HBF₄·Et₂O in methanol afforded the ketonyl complexes TpRuCl(CH₂C(O)R)(NO) (R = Ph (2a), p-CH₃C₆H₄ (2b), ^tBu (2c), CH₂CH₂OMe (2d), CH₂OH (2e)) and the α,β-unsaturated acyl complexes TpRuCl(C(O)CHCR‘₂)(NO) (R‘ = Me (3f), Ph (3g)), respectively. While the latter were produced by hydration via allenylidene species, the former were presumably generated from the reaction of η²-coordinated 1-alkyne species with adventitious water.