Hydridoruthenium Complexes Research Articles

Coordinatively Unsaturated Hydridoruthenium(II) Complexes of N-Heterocyclic Carbenes

The saturated imidazolin-2-ylidene compounds RNC3H4NR, with R = mesityl (SIMes), 2,6-diisopropylphenyl, were synthesized by use of diamines that were prepared by the hydrogenation of the corresponding diimines catalyzed by RuHCl(R-binap)(R,R-dach)/KOtBu in toluene. The ligands IMes (MesNC3H2NMes) and SIMes react with RuHCl(PPh3)3 to give RuH(SIMes-H)(PPh3)2 (1) and RuH(IMes-H)(PPh3)2 (2), respectively, where there is cyclometalation of a C−H bond of an ortho Ar−CH3 group. The reaction of RuHCl(PPh3)3 with ItBu (tBuNC3H2NtBu) produces ItBu·HCl and a red solution that, upon reaction with H2, produces the dihydride Ru(H)2(ItBu)(PPh3)2 as a mixture of the two isomers 3a (trans PPh3 ligands) and 3b (cis PPh3). These isomers have an agostic C−H bond from a methyl group. There is an interesting windshield wiper exchange of coordinated tert-butyl groups occurring in isomer 3a, as monitored in solution by VT NMR with a free energy of activation of 11.8 kcal/mol. The reaction of 2 with CO at 20 °C produces (OC-34)-...

Selective Bond Cleavage Reactions by Low‐Valent Ruthenium Complexes

AbstractFor Abstract see ChemInform Abstract in Full Text.

低原子価ルテニウム錯体による選択的結合切断反応の開発

Reactions of zero-valent ruthenium complex [Ru (η4-1, 5-COD) (η6-1, 3, 5-COT)] (1) (COD = cyclooctadiene, COT = cyclooctatriene) with a series of monodentate tertiary phosphines cause selective displacement of the COD ligand to give Ru (COT) complexes, in which the COT ligand coordinates to the Ru either by η4 or η1 : η3 fashion [[Ru (1-4-η4-1, 3, 5-COT) L3] {L = PEt3 (2a), PBu3 (2b), PEt2Ph (2c)}, [Ru (6-η1 : 1-3-η3-COT) L3] {L = PMe3 (3a), PMe2Ph (3b)}]. The highly reduced zero-valent complex 2a-c, shows higher activity toward C-O bond cleavage reaction of alkenyl carboxylate than 1 and 1/phosphine system. Complex 1/phosphine system shows high activity toward versatile bond cleavage reactions such as C-O bond of vinylic and allylic carboxylates or ethers, C-S bond of sulfide or thiophenes, and sp3 C-H bond of ortho substituted phenols or carboxylic acids. Oxidative addition of C-H bond in active methylene compounds takes place to give hydrido (enolato) ruthenium (II) complexes, where zwitterionic structure of the enolato ligand derived from cyanoesters enhances their nucleophilic character to act as an active intermediate in Murahashi aldol and Michael reactions catalyzed by low-valent ruthenium complex.

A series of ruthenium(ii) complexes containing the bulky, functionalized trialkylphosphines tBu2PCH2XC6H5 as ligands

The monomeric ruthenium(II) complexes [(η6-C6H5XCH2PtBu2-κ-P)RuCl2] 3, 4 were prepared either on a reductive route from RuCl3·3H2O and tBu2PCH2XPh (X = CH2 1, OCH2 2) or by ligand replacement reactions from [(p-cym)RuCl2]2 and the phosphine via the p-cymene compounds [(p-cym)(C6H5XCH2PtBu2-κ-P)RuCl2] 6, 7 as intermediates. Abstraction of one chloro ligand from 3 with AgPF6 led to the formation of the dinuclear complex [{(η6-C6H5CH2CH2PtBu2-κ-P)RuCl}2](PF6)2 8, which reacts with acetone, CH3CN and PMe3 by bridge cleavage to afford the mononuclear compounds [(η6-C6H5CH2CH2PtBu2-κ-P)RuCl(L)]PF6 9, 10, 12. Both 10 and 11 (the latter containing 2 as chelating ligand) were also obtained from 3, 4 and AgPF6 in the presence of acetonitrile. Hydridoruthenium(II) complexes [(η6-C6H5XCH2PtBu2-κ-P)RuHCl] 13, 14, [RuHCl(H2)(L)2] 15 (L = 1), 16 (L = 2) and [RuHCl(CO)(2)2] 17 could be prepared from RuCl3·3H2O and 1 or 2 in the presence of NEt3 under reductive conditions. Insertion, substitution and addition reactions of compound 17 led to the formation of [Ru(CHCH2)Cl(CO)(2)2] 18, [RuHF(CO)(2)2] 19, and [RuHCl(CO)2(2)2] 20, respectively. The cationic allenylidene complexes [(η6-C6H5XCH2PtBu2-κ-P)RuCl(CCCPh2)]A 22a,b (X = CH2; A = BF4, PF6) and 23 (X = OCH2; A = PF6) were prepared from 3, 4 or 13, HCCC(OH)Ph2 and either one equiv. of AgPF6 or an equivalent amount of HBF4 in diethyl ether. Treatment of 15 and 16 with acetylene afforded the five-coordinate vinylideneruthenium(II) compounds [RuHCl(CCH2)(L)2] 24, 25 which in the presence of HBF4 are highly efficient catalysts for the Ring Opening Metathesis Polymerization (ROMP) of cyclooctene. The molecular structures of 10 and 17 were determined crystallographically.

Formation and characterization of water-soluble hydrido-ruthenium(II) complexes of 1,3,5-triaza-7-phosphaadamantane and their catalytic activity in hydrogenation of CO2 and HCO3- in aqueous solution.

The water-soluble tertiary phosphine complex of ruthenium(II), [RuCl2(PTA)4], (PTA = 1,3,5-triaza-7-phosphaadamantane) was used as catalyst precursor for hydrogenation of CO2 and bicarbonate in aqueous solution, in the absence of amine or other additives, under mild conditions. Reaction of [RuCl2(PTA)4] and H2 (60 bar) gives the hydrides [RuH2(PTA)4] (at pH = 12.0) and [RuH(PTA)4X] (X = Cl- or H2O) (at pH = 2.0). In presence of excess PTA, formation of the unparalleled cationic pentakis-phosphino species, [HRu(PTA)5]+, was unambiguously established by 1H and 31P NMR measurements. The same hydrides were observed when [Ru(H2O)6][tos]2 (tos = toluene-4-sulfonate) reacted with PTA under H2 pressure. The rate of CO2 hydrogenation strongly depends on the pH. The highest initial reaction rate (TOF = 807.3 h(-1)) was determined for a 10% HCO3-/90% CO2 mixture (pH = 5.86), whereas the reduction was very slow both at low and high pH (CO2 and Na2CO3 solutions, respectively). 1H and 31P NMR studies together with the kinetic measurements suggested that HCO3- was the real substrate and [RuH(PTA)4X] the catalytically active hydride species in this reaction. Hydrogenation of HCO3- showed an induction period which could be ascribed to the slow formation of the catalytically active hydride species.

An NMR Study on the Ruthenium Complex-Catalyzed C-H/Olefin Coupling Reaction

Abstract A dihydridoruthenium(II) complex, [RuH2(CO)(PPh3)3], reacts with styrene to give two species: a bis(styrene)ruthenium(0) complex, [Ru(CO)(CH2=CHPh)2(PPh3)2], and a cyclometallated hydridoruthenium(II) one, [Ru(C6H4PPh2)H(CO)(PPh3)2]. The complex [RuH2(CO)(PPh3)3] reacts with isoprene to give a piano-stool type ruthenium(0) complex [Ru(η4-CH2=CMeCH=CH2)(CO)(PPh3)2]. In reactions among [RuH2(CO)(PPh3)3], styrene, and 3′-(trifluoromethyl)acetophenone, three cyclometallated hydridoruthenium(II) complexes: P,P′-cis-C,H-cis-, P,P′-trans-C,H-trans-, and P,P′-trans-C,H-cis-[Ru{C6H3(CF3)C(=O)Me}H(CO)(PPh3)2] are detected by NMR spectroscopy. The 1H NMR spectra of the reaction mixture exhibit the catalytic formation of 2′-(2-phenylethyl)- and 2′-(1-phenylethyl)-5′-(trifluoromethyl)acetophenones. On the basis of these findings, a mechanism for the C-H/olefin coupling reaction is discussed. The first of the three complexes is assigned to an active intermediate in the catalytic coupling reaction, whereas the other two are assigned as quasi-stable ruthenium(II) complexes which are in equilibrium with active species.

ChemInform Abstract: The Role of Functionalized Phosphines in the Hydrogenation of Carboxylic Acids in the Presence of Phosphine Substituted Hydrido Ruthenium Complexes.

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The role of functionalized phosphines in the hydrogenation of carboxylic acids in the presence of phosphine substituted hydrido ruthenium complexes

Hydrido ruthenium carbonyl complexes substituted by functionalized phosphines such as H4Ru4(CO)8[P(CH2OCOR)3]4 have been synthesized and tested as catalysts in the hydrogenation of carboxylic acids. These complexes are more active than those reported previously, containing trialkyl- or triarylphosphines. On the basis of their behavior, their different activity has been explained in terms of an involvement of the phosphine ligand in the catalytic cycle. The ester group present in the phosphine P(CH2OCOR)3 is hydrogenated to produce an alcohol (RCH2OH) and a P(CH2OH) group which, in turn, reacts with the free acid present in solution to restore the P(CH2OCOR) group. This hypothesis has been confirmed by the reactivity of the possible intermediate H4Ru4(CO)8[P(CH2OH)3]4 with acetic acid. Another support to this statement is the almost equal catalytic activity, displayed by H4Ru4(CO)8[P(CH2OCOR)3]4 complexes, whatever the R group present, in the phosphine ligand, in the hydrogenation of carboxylic acids. These complexes, on the other hand, are less active than the corresponding tributylphosphine substituted ones in the hydrogenation of alkenes and ketones. Finally when the phosphine ligand is P(CH2CH2COOCH3)3 the ester group is not reduced and consequently the catalytic activity of this complex in the hydrogenation of carboxylic acids is very low.

Reactions of [RuClH(CO)(PPh 3) 3] with 2-methyl-2-propen-1-ol. Reversible insertion/ β-elimination, and reductive elimination on a 3-hydroxy-2-methylpropyl- C1, O-ruthenium(II) complex

A hydridoruthenium complex [RuClH(CO)(PPh 3) 3] ( 1) reacts with 2-methyl-2-propen-1-ol at room temperature to give an insertion product, [Ru{CH 2CH(CH 3)CH 2OH}Cl(CO)(PPh 3) 2] ( 2), which undergoes β-elimination of 2-methyl-2-propen-1-ol reversibly in solution. The complex 1 reacts with 2-methyl-2-propen-1-ol under benzene refluxing conditions to produce 2-methylpropan-1-ol, 2-methylpropanal and 2-methyl-2-propenal catalytically in the presence of water. The production of 2-methylpropanal results in formation of two isomers of 2-methylpropanoato complex [RuCl{ η 2-(CH 3) 2CHCO 2}(CO)(PPh 3) 2] ( 3). Heating 1 at 80°C in neat 2-methyl-2-propen-1-ol affords a novel ruthenium( O) complex [Ru{ η 4-CH 2C(CH 3)CHO}-(CO)(PPh 3) 2] ( 7) and a quaternary phosphonium salt [Ph 3PCH 2CH(CH 3)CH 2OH]Cl ( 8) via reductive elimination of 3-chloro-2methylpropan-1-ol from 2. The molecular structures of 7 and 8 are determined by X-ray crystallography.

Two Isomeric Structures of Hydridoruthenium Complexes Supported by Hydrotrispyrazolylborates, TpRRu(H)(1,5-cyclooctadiene): An Octahedral Structure with Additional 3-Center-2-Electron Ru−H−B Interaction Is More Stable than a Square-Pyramidal Structure with a κ2-TpR Ligand

Hydrido-cod-ruthenium complexes containing hydrotris(3,5-diisopropylpyrazolyl)borate (TpiPr) and its 4-brominated derivative (TpiPrBr), TpRRu(H)(cod), are reported. Spectroscopic and crystallograph...

Cyclovoltammetric studies on the reaction of dihydridotetrakis(triphenylphosphane)ruthenium(II) with methyl acrylate. CH-activation of methyl acrylate in the presence of Ru(0)(MA) 2(PPh 3) 2

Electrochemical studies on RuH 2(PPh 3) 4 ( 1) and Ru(0)(MA) 2(PPh 3) 2 ( 2), the complex that is generated when RuH 2(PPh 3) 4 is dissolved in methyl acrylate (MA), are carried out by cyclic voltammetry (CV). The combination of electrochemical with NMR spectroscopic measurements reveals that MA undergoes oxidative addition to Ru(0)(MA) 2(PPh 3) 2 via cleavage of a vinylic CH bond. The resulting hydridoruthenium(II) complex is not stable in MA and forms presumably a complex in which a further MA is inserted into the ruthenium–hydrogen bond.

Unusual Formation of Cyclometallated C,H-trans-Hydridoruthenium(II) Complexes and Their Isomerization into C,H-cis-Types

Abstract The aromatic C-H bonds of N-benzylideneaniline and 2-phenylpyridine are cleaved by [RuH2(CO)(PPh3)3] and triethoxyvinylsilane at 70-110 °C to give the corresponding cyclometallated hydridoruthenium(II) complexes. The X-ray structure analyses of these complexes reveal that the hydrido ligand is initially situated trans to aryl group of the cyclometallated moiety and these two ligands are moved mutually into cis-sites by heating.

The Square Pyramidal Hydride Cation [RuH(dcpe)2]+, dcpe = Bis(dicyclohexylphosphino)ethane. Structures of [RuH(dcpe)2]+[BPh4]- and of the Zwitterionic {(η6-C6H5)BPh3}RuH(dcpe)

Two hydrido ruthenium complexes could be isolated from the reaction between RuCl2(DMSO)4 (DMSO = dimethyl sulfoxide) and the chelating 1,2-bis(dicyclohexylphosphino)ethane (dcpe) and [BPh4]-. These are [RuH(dcpe)2]+[BPh4]- with a five-coordinate, 16 valence electron cation and the neutral zwitterionic 18 valence electron compound {(η6-C6H5)BPh3}RuH(dcpe). The relative amounts of these products depend on the reaction conditions. If NaBPh4 is replaced by NH4PF6 or added after the reaction with the diphosphine has gone to completion, the 16 valence electron species [RuH(dcpe)2]+ is the only product. Reducing the size of the diphosphine chelate to 1,1-bis(dicyclohexylphosphino)methane (dcpm) has a large effect on the reaction course. Either trans-RuHCl(dcpm)2 or trans-RuCl2(dcpm)2 is formed, depending on the conditions. X-ray structures of [RuH(dcpe)2]+[BPh4]- (monoclinic, P2/c, a = 24.936(5) Å, b = 12.633(3) Å, c = 25.801(5) Å, β = 102.86(3)°, V = 7924(3) Å3, Z = 4, R = 0.062, Rw = 0.1694) and {(η6-C6H5)BPh3}RuH(dcpe) (monoclinic, P21/n, a = 14.321(5) Å, b = 19.716(7) Å, c = 17.100(5) Å, β = 107.60°, V = 4602(3) Å3, Z = 4, R = 0.0648, Rw = 0.1873) have been determined. A nearly planar arrangement of the four P atoms exists around Ru in the five-coordinate cation, implying a distorted square pyramid. This structural motif has not been observed previously for a d6 RuL5 system with a P4X donor set. {(η6-C6H5)BPh3}RuH(dcpe) represents an example for the noninnocent behavior of the “noncoordinating” [BPh4]- anion. The coordinated six-membered ring displays a boatlike distortion with the BPh3 “substituent” and the para-carbon of the coordinated ring displaced away from the metal.

New Types of Coupling Reactions of Some Nitriles on Ruthenium Complexes

Abstract A hydridoruthenium(II) complex [RuClH(CO)(PPh3)3] reacts with o-toluonitrile and water at 120 °C to give a novel five-membered cyclometallated complex, [Ru(C6H3MECH=NCH2C6H4Me-o)Cl(CO)(PPh3)2]. The hydrido complex reacts with benzoylacetonitrile at 80 °C to form a six-membered chelate complex, [RuCl{O=C(Ph)C(CN)=C(CH2COPh)NH}(CO)(PPh3)2].

Synthesis, Characterization, and Behavior of Hydridoruthenium Carbonyl Clusters Substituted with Functionalized Phosphines in the Presence of Hydrogen. 1. H4Ru4(CO)8[P(CH2OCOR)3]4 (R = CH3−, C2H5−, (CH3)2CH−, (CH3)3C−, (S)-C2H5CH(CH3)−)

The synthesis and characterization of phosphines containing ester groups P(CH2OCOR)3 (R = CH3−, C2H5−, (CH3)2CH−, (CH3)3C−, (S)-C2H5CH(CH3)−) are reported. The new hydridoruthenium complexes H4Ru4(CO)8[P(CH2OCOR)3]4 (R = CH3−, C2H5−, (CH3)2CH−, (CH3)3C−, (S)-C2H5CH(CH3)−) were synthesized and characterized. The structure of (+)-(S)-H4Ru4(CO)8{P[CH2OCOCH(CH3)C2H5]3}4 was determined by X-ray diffraction. The behavior of these complexes in hydrocarbon solution with hydrogen under pressure (130 atm) in the temperature range 25−130 °C has been investigated. The ester groups present in the ligand P(CH2OCOR)3 are hydrogenated under mild conditions with formation of the corresponding alcohol RCH2OH.

The First Triisopropylstibane Ruthenium(II) and Ruthenium(0) Complexes Including the X‐ray Crystal Structure of [Ru(η3‐C3H5)2(SbiPr3)2

AbstractThe hydridoruthenium(II) complexes [RuHCl(H2)(SbiPr3)3] (2) and [RuH2(H2(SbiPr3)3] (3), containing dihydrogen as ligand, were prepared from [RuCl2(C8H12)]n (1) as the starting material. Compound 3 reacts with CO by displacement of H2 to yield [RuH2(CO)(SbiPr3)3] (4) and with C2H4 to give both [RuH2(C2H4)2(SbiPr3)2] (5) and [RuH2(C2H4)(SbiPr3)3] (6), the latter as the more stable and isolable product. Treatment of 3 with propene leads to the formation of [Ru(η3‐C3H5)2] (7) while the reaction of 3 with butadiene affords the pentacoordinated ruthenium(0) compound [Ru(η4‐C4H6)2(SbiPr3)] (8). The molecular structure of the bis‐(allyl) complex 7 was determined by X‐ray crystallography.

Versatile Reactivity of the Bis(dihydrogen) Complex RuH2(H2)2(PCy3)2 toward Functionalized Olefins: Olefin Coordination versus Hydrogen Transfer via the Stepwise Dehydrogenation of the Phosphine Ligand

Treatment of RuH2(H2)2(PCy3)2 (1) with ethylene leads to the formation of [RuH{η3-C6H8)PCy2}(C2H4)(PCy3)] (2), which contains an η3-cyclohexenyl ring. Upon addition of 3 equiv of an alkene bearing σ-donor substituents such as CH2CH(SiEt3) or CH2CHtBu, 1 transforms in high yield into the trihydridoruthenium(IV) complex [RuH3{(η3-C6H8)PCy2}(PCy3)] (3) and the corresponding alkane is obtained quantitatively. Further hydrogen abstraction from 1 can be achieved by using 5 equiv of alkene, leading to the hydridoruthenium(II) complex [RuH{(η3-C6H8)PCy2}{(η2-C6H9)PCy2}] (4). This is the first complex where C−H activation within two cyclohexyl rings of two tricyclohexylphosphines has occurred. 4 can also be obtained by treatment of 3 with 2 equiv of alkene. The reactions can be reversed by bubbling dihydrogen into a solution of 2−4 yielding 1 at the final stage of hydrogenation. 3 and 4 undergo rapid H−D exchange with the deuterated solvent. Reaction of 1 with alkenes bearing electron-withdrawing substituents such as CH2CHCO2Me or trans-MeO2CCHCHCO2Me allows the formation of the hydrido dihydrogen complexes [RuH(H2)(η2-O2CCH2CH3)(PCy3)2] (5) and [RuH(H2)(η2-O2CCH2CH2CO2Me)(PCy3)2] (6), respectively. An X-ray structure determination on 5 was carried out. Surprisingly, reaction of 1 with cis-MeO2CCHCHCO2Me yielded the alkene-coordinated complex [RuH2(η2-CH3O2CCHCHCO2CH3)(PCy3)2] (7). Variable-temperature NMR studies on 7 showed a barrier of rotation for the alkene of 10.5 kcal/mol. 7 was shown to catalyze cis−trans MeO2CCHCHCO2Me isomerization.

Synthesis and spectroscopic studies of new hydridoruthenium complexes: catalytic reactions of [RuHCl(bpzm)(cod)] (bpzm = bis(pyrazol-1-yl)methane, cod = cycloocta-1,5-diene)

The reaction of [RuHCl(bpzm)(cod)] ( 1) (bpzm = bis(pyrazol-1-yl)methane, cod = cycloocta-1,5-diene) with one equivalent of AgCF 3SO 3 afforded the triflate-containing [RuH(CF 3SO 3)(bpzm)(cod)] ( 2). The reaction of 2 with PMe 2Ph allowed the synthesis of trans-[RuH(PMe 2Ph)(bpzm)(cod)]CF 3SO 3 (bd3a), which isomerizes easily to cis-[RuH(PMe 2Ph)(bpzm)(cod)]CF 3SO 3 ( 3b), while a similar reaction of 1, in the presence of AgCF 3SO 3, gave a series of phosphine-containing complexes such as [RuH(CF 3SO 3)(cod)(PMe 2Ph) 2] ( 4), the products of this process greatly depending on the reaction conditions. The complex trans-[RuH{P(OMe) 3}(bpzm)(cod)]CF 3SOP 3 ( 5a), which also readily isomerizes to cis[RuH{P(OMe) 3}(bpzm)(cod)]CF 3SO 3 ( 5b), was isolated from the reactions of 2 with P(OMe) 3, or alternatively from the reaction of 1 with P(OMe) 3 and AgCF 3SO 3. Finally, the reaction of 2 or 1 (in the presence of AgCF 3SO 3) with N-donors pyridine, 4-methylpyridine (4-picoline) or 3,5-dimethylpyridine (3,5-lutidine) yielded a mixture of products which we believe to contain both cis- and trans-[RuHL(bpzm)(cod)]CF 3SO 3 (L = pyridine, 4-picoline, or 3–5-lutidine). Spectroscopic data are provided for these compounds. Complex 1 catalyzes both the hydrogenation of the unsaturated substrates cyclohexene, cyclohexanone, acetone and propanal, with turn-over rates of up to 1506 h −1 for cyclohexanone in the presence of NaOH at 130°C, and the efficient transfer hydrogenation of cyclohexanone by propan-2-ol in the presence of NaOH at 80°C, with a turn-over rate of 880 h −1.

Formation of N-imidoylimidatoruthenium(II) complexes via ruthenium-promoted hydration of nitriles

The hydridoruthenium(II) complex [RuCl(H)(CO)(PPh3)3]1 reacted with aromatic nitriles at 120 °C in the presence of water to give novel N-imidoylimidatoruthenium(II) complexes [RuCl(NHCRNCRO)(CO)(PPh3)2](R = C6H4Me-p2, Ph 3, or C6H4Me-m4). In contrast, reaction of o-toluonitrile with 1 gave a small amount of the corresponding N-imidoylimidato complex and a considerable amount of o-toluamide. When 1 was heated at 120° in a 1 : 1 mixture of an amide R 1CONH2 and a nitrile R2CN a cross-linked N-imidoylimidato complex [RuCl(NHCR 2NCR 1O)(CO)(PPh3)2]6(R1= Ph, R2= C6H4Me-p) or 7(R1= C6H4Me-p, R2= Ph) was obtained. Single-crystal structure analyses of 2 and 6 have been performed.

Die fördernde Rolle von Phosphinoester‐Liganden bei der Synthese neutraler Carben‐, Vinyliden‐ und Allenyliden‐Ruthenium(II)‐Komplexe

AbstractVinylidene Transition‐Metal Complexes, XXXV[1]. — The Supporting Role of Phosphino Ester Ligands for the Synthesis of Neutral Carbene, Vinylidene and Allenylidene Ruthenium(II) ComplexesThe reaction of [RuCl2(PPh3)3] (1) with the phosphino esters iPr2P(CH2)nCO2R (2–4) leads to complete (n = 1; R  CH3, C2H5) or partial (n = 2; R CH3) displacement of the PPh3 ligands and formation of the octahedral ruthenium(II) complexes [RuCl2{k2(P,O)‐iPr2PCH2CO2R}2] (5, 6) and [RuCl2(PPh3){k(P)‐iPr2PCH2CH2CO2Me}{k2(P,O)‐iPr2PCH2CH2CO2Me}] (7). Treatment of 5 with LiBr and LiI affords the dibromo‐ and diiodoruthenium derivatives 8 and 9. While compound 5 reacts with CO and SO2 by cleavage of one Ru—O bond to yield the 1:1 adducts [RuCl2(L){k(P)‐iPr2PCH2CO2Me}{k2(P,O)‐iPr2PCH2CO2Me}] (10, 11), the reaction of the dibromo derivative 8 with CO in solution gives the dicarbonyl complex [RuBr2(CO)2{k(P)‐iPr2PCH2CO2Me}2](13). If CO is passed over 8 in the solid state, the corresponding monocarbonyl compound 14 is formed. The hydridoruthenium(II) complex 16, which is obtained from equimolar amounts of [RuHCl(CO)(PiPr3)2] (15) and 2, reacts with HCCMe by insertion to give the vinyl derivative [RuCl{E—CHCHMe}(CO)(PiPr3){k2(P,O)‐iPr2CH2CO2Me}] (17). Treatment of 5 with HC̊' (R'  H, Me, tBu, Ph) and of 6, 8, 9 with HCCPh affords upon photochemical activation the octahedral vinylidene complexes [RuX2‐(CCHR){k(P)‐iPr2PCH2CO2R}{k2(P,O)‐iPr2PCH2CO2R}] (18–21 and 23–25) in good to excellent yield. At room temperature, these compounds (with the exception of 25) are highly fluxional in solution. From 31P‐NMR measurements, the free energies of activation ΔG‡ for the intramolecular rearrangement have been determined. Whereas the reaction of 5 with HCČH2CH2OH leads to the carbene complex 30 containing the cyclic oxycarbene :C(CH2)3O as ligand, the functionalized vinylidene derivatives 31 and 32 are formed on treatment of 5 with aryl‐substituted alkynols HC≡RR'OH (R  Ph, R'  Ph, o‐Tol). These react in toluene solution at 80°C by elimination of water to give the allenylidene complexes [RuCl2(CCCRR'){k(P)‐iPr2PCH2CO2Me}{k2(P,O)‐iPr2PCH2CO2Me}] (33, 34). The X‐ray structure analysis of 33 reveals a trans disposition of the chloro ligands, the phosphorus atoms as well as of one CO oxygen and the α‐C atom of the allenylidene unit. Compound 33 reacts with CO, CNtBu and pyridine to give the 1:1 adducts [RuCl2(L)(CCCPh2){k(P)‐iPr2PCH2CO2Me}2] (35–37) and with HCl by attack on the central CC bond to yield the vinylcarbene complex [RuCl2(C(Cl)CHCRR'){k((P)‐iPr2‐PCH2CO2Me}{k2(P,O)‐iPr2PCH2CO2Me}] (38). The preparation of the phosphino ketone iPr2PCH2C(O)CH3 (40) and its ruthenium complexes 41 and 42 is briefly described.