Differential Reactivity of [TpRu(κ 2 P , N ‐ i Pr 2 PXPy)Cl] (X = NH, S) Bearing Hemilabile Coligands Towards NaBAr F 4 , Lithium Acetylide, and Acetylenes

In contrast with [TpRu(κ 2 P , N ‐ i Pr 2 PNHPy)Cl] ( 1a , Tp = trispyrazolylborate), [TpRu(κ 2 P , N ‐ i Pr 2 PSPy)Cl] ( 1b ) reacts with sodium tetrakis[3,5‐bis(trifluoromethyl)phenyl]borate (NaBAr F 4 ) in fluorobenzene under nitrogen to afford the dinuclear complex [{TpRu(κ 2 P , N ‐ i Pr 2 PSPy)} 2 (μ‐Cl)][BAr F 4 ] ( 1b′ ). Through diverse synthetic strategies, a series of neutral acetylides [TpRu(C≡CR)(κ 2 P , N ‐ i Pr 2 PXHPy)] [X = NH; R = Ph ( 2a ), SiMe 3 ( 2b ); X = S; R = Ph ( 2c ), p ‐C 6 H 4 Br ( 2d ), COOMe ( 2e )], cationic vinylidene complexes [TpRu(=C=CHR)(κ 2 P , N ‐ i Pr 2 PNHPy)] + [X = NH; R = Ph ( 3a ), SiMe 3 ( 3b ); X = S; R = Ph ( 3c ), p ‐C 6 H 4 Br ( 3d )] and [TpRu(=C=CH 2 )(κ 2 P , N ‐ i Pr 2 PNHPy)] + ( 3e ), and a cationic η 2 ‐alkyne complex [TpRu(η 2 ‐HC≡CCOOMe)(κ 2 P , N ‐ i Pr 2 PSPy)][BAr F 4 ] have been efficiently synthesized from 1a and 1b . The methoxy(methyl)carbene complexes [TpRu{=C(OMe)CH 3 }(κ 2 P , N ‐ i Pr 2 PXPy)][BPh 4 ] [X = NH ( 5a ), S ( 5b )] were isolated from the reactions of 1a and 1b with acetylene gas in the presence of NaBAr F 4 in methanol. The deprotonation of the cationic vinylidenes derived from 1b with K t BuO affords the corresponding neutral acetylide complexes, which undergo facile protonation with CF 3 SO 3 H to reproduce the cationic vinylidenes quantitatively.