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.