Ruthenium Allenylidene Complexes Research Articles

Ring Closing versus Cyclic Isomerization of 1,6‐Dienes by Ruthenium Allenylidene Complexes

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Allenylidene‐Ruthenium Complexes as Versatile Precatalysts for Alkene Metathesis Reactions

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Allenylidene–ruthenium complexes as versatile precatalysts for alkene metathesis reactions

Abstract Recent developments of ruthenium–allenylidene complexes as precatalysts for alkene metathesis reactions are described. Since the first evidence, reported in 1998 by the Dixneuf and Furstner’s groups, a variety of ionic 18-electron and neutral 16-electron ruthenium–allenylidene complexes mainly of the type [RuCl(CCCR 2 )(arene)(PR 3 )][X] and RuCl 2 (CCCR 2 )(L′)(L″) have been described. The parallel formation and catalytic activity of related complexes in which the allenylidene moiety is formally transformed into an indenylidene ligand, that may take place via intramolecular rearrangement, is discussed. Applications are described for the production of both fine chemicals and polymers. Attempts for catalyst recycling in ionic liquids, or via heterogenization are also presented.

Ruthenium‐Catalysed Selective Transetherification of Substituted Vinyl Ethers To Form Acetals and Aldehydes

AbstractThe water‐soluble ruthenium allenylidene complex [{RuCl(μ‐Cl)(C=C=CPh2)(TPPMS)2}2]Na4 catalyses the selective transformation of substituted linear and cyclic vinyl ethers with MeOH, under mild non acidic conditions, to give acetals, while aldehydes and ketones are obtained in a CHCl3/H2O mixture, which allows for easy recycling of the catalyst. NMR studies showed that the reaction follows a transetherification mechanism rather than simple acid‐catalysed hydrolysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Ruthenium‐Catalyzed Propargylation of Aromatic Compounds with Propargylic Alcohols.

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Indenyl–ruthenium(ii) allenylidene complexes containing terpenic substituents as precursors of optically active terminal alkynes: scope and limitations

The optically active allenylidene complex [Ru{CCC(C9H16)}(η5-C9H7)(PPh3)2][PF6] (C(C9H16) = (1R,4S)-1,3,3-trimethyl-bicyclo[2.2.1]hept-2-ylidene) 1 regio- and stereoselectively reacts with unhindered anionic nucleophiles to yield the neutral σ-alkynyl derivatives [Ru{CCC(C9H16)R}(η5-C9H7)(PPh3)2] (R = H 2a, CN 2b, Me 2c, CCPh 2d). Protonation of 2a–d with HBF4·Et2O affords the cationic vinylidene complexes [Ru{CC(H)C(C9H16)R}(η5-C9H7)(PPh3)2][BF4] 3a–d, which can be easily demetalated, by treatment with acetonitrile, yielding the corresponding chiral acetylenic compounds HCC(C9H16)R 4a–d. The novel optically active indenyl–ruthenium(II) allenylidene complexes [Ru{CCC(C9H16)}(η5-C9H7)(PPh3)2][PF6] (C(C9H16) = (1R,4R)-1,7,7-trimethyl-bicyclo[2.2.1]hept-2-ylidene) 9 and [Ru{CCC(C9H14)}(η5-C9H7)(PPh3)2][PF6] (C(C9H14) = (1S,5S)-4,6,6-trimethyl-bicyclo[3.1.1]hept-3-en-2-ylidene) 10 have been prepared by activation of propargylic alcohols derived from the natural ketones (+)-camphor and (−)-verbenone, respectively, with [RuCl(η5-C9H7)(PPh3)2] 6. Treatment of 9 with anionic nucleophiles generates the neutral σ-enynyl complex [Ru{CCC(C9H15)}(η5-C9H7)(PPh3)2] 11 (C(C9H15) = (1R,4R)-1,7,7-trimethyl-bicyclo[2.2.1]hept-2-en-2-yl).

Allenylidene-ruthenium-arene precatalyst for ring opening metathesis polymerisation (ROMP)

The ruthenium allenylidene complex [RuCl(CCCPh 2)(PCy 3)( p-cymene)][OTf] constitutes an excellent precatalyst for the ROMP at room temperature of norbornene ( M n=198×10 3, PDI=1.8) and cyclooctene ( M n=143×10 3, PDI=1.9). The activation of the precatalyst by initial heating (25 min, 60 °C) generates a catalytic species that operates at room temperature to produce in 10 min 90% of polyoctenamer ( M n=151×10 3, PDI=1.7).

Generation of polyunsaturated cumulene chains by unprecedented insertions of the ynamine MeC=_NEt2 in ruthenium(II) allenylidene complexes.

Three-fold sequential insertion of the ynamine MeCCNEt2 into ruthenium(II) allenylidene complexes leads to the stereoselective formation of the polyunsaturated complex I.

In Search of Optically Active γ-Keto Acetylenes via Regioselective Coupling of Allenylidene Groups and Cyclic Enolates

(Indenyl)ruthenium(II) allenylidene complexes [Ru{CCC(R)Ph}(η5-C9H7)(PPh3)2][PF6] (R = Ph (1), H (2)) regioselectively react with enolates derived from cyclopentanone and cyclohexanone at the Cγ atom to yield the σ-alkynyl derivatives (R = Ph, n = 1 (3a), 2 (3b); R = H, n = 1 (4a), 2 (4b)). Protonation of these species at Cβ of the alkynyl chain with HBF4 affords vinylidene complexes 5a,b and 6a,b, which can easily be demetalated with acetonitrile to yield the γ-keto acetylenes (7a,b and 8a,b). Compounds 4a,b, 6a,b and 8a,b, derived from the monosubstituted allenylidene complex 2, have been obtained as nonseparable mixtures of two diastereoisomers. The optically active allenylidene [Ru{CCC(C9H16)}(η5-C9H7)(PPh3)2][PF6] (10) (C(C9H16) = (1R)-1,3,3-trimethylbicyclo[2.2.1]hept-2-ylidene) undergoes a selective exo addition of the cyclopentanone enolate to afford the σ-alkynyl diastereoisomers (11a,b). Demetalation of 11a and 11b, via their corresponding vinylidenes, allows the preparation of optically pure te...

First ring-opening metathesis polymerization in an ionic liquid. Efficient recycling of a catalyst generated from a cationic ruthenium allenylidene complex

Download options Please wait... Article information DOI https://doi.org/10.1039/B205920G Article type Paper Submitted 19 Jun 2002 Accepted 16 Jul 2002 First published 07 Oct 2002 Download Citation New J. Chem., 2002,26, 1667-1670 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions First ring-opening metathesis polymerization in an ionic liquid. Efficient recycling of a catalyst generated from a cationic ruthenium allenylidene complex S. Csihony, C. Fischmeister, C. Bruneau, I. T. Horváth and P. H. Dixneuf, New J. Chem., 2002, 26, 1667 DOI: 10.1039/B205920G To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Social activity Tweet Share Search articles by author Szilárd Csihony Cédric Fischmeister Christian Bruneau István T. Horváth Pierre H. Dixneuf

Preparation of new ruthenium–allenylidene catalysts and their use in polymerisation of cyclic olefins

A variety of ruthenium–allenylidene complexes were produced in two steps from the simple RuCl 2(dmso) 4 precursor: the neutral RuCl 2(CCCR 2)(PCy 3) n (dmso) m and the cationic [RuCl(CCCR 2)(PCy 3) n (dmso) m ]TfO complexes. Some of them have been evaluated for polymerisation of norbornene and cyclooctene, and constitute the first example of active RuCCCR 2 catalysts for ring opening metathesis polymerisation (ROMP). The most active system is the cationic [RuCl(CCCPh 2)(PCy 3)(dmso) 2]TfO complex 5 which leads in PhCl at 80 °C to 90% of polycyclooctene with a polydispersity of 1.89 and 69% of cis-configuration of CHCH bonds. The presence of an electron-donating group on the aryl substituents ( p-OMe) drastically favours both yield and low polydispersity of the polymer.

Dehydrogenative Dimerization of Tin Hydrides Catalyzed by Ruthenium-Allenylidene Complexes.

Conjuring with conjugation: catalysis by ruthenium-allenylidene complexes has been observed for the conversion of tin hydrides into distannanes and dihydrogen. Alkyne or alkene groups (R) in conjugation with an aromatic ring are required for catalytic activity, providing an unusual example of control of metal-centered reactivity by a remote substituent.

Dehydrogenative Dimerization of Tin Hydrides Catalyzed by Ruthenium–Allenylidene Complexes

Dehydrogenative Dimerization of Tin Hydrides Catalyzed by Ruthenium–Allenylidene Complexes

Dehydrogenative Dimerization of Tin Hydrides Catalyzed by Ruthenium-Allenylidene Complexes

Dehydrogenative Dimerization of Tin Hydrides Catalyzed by Ruthenium-Allenylidene Complexes

Cationic ruthenium allenylidene complexes as catalysts for ring closing olefin metathesis

A series of well accessible cationic ruthenium allenylidene complexes of the general type [(eta6-arene)(R3P)RuCl(=C=CR'2)]+ X- is described which constitute a new class of pre-catalysts for ring closing olefin metathesis reactions (RCM) and provide an unprecedented example for the involvement of metal allenylidenes in catalysis. They effect the cyclization of various functionalized dienes and enynes with good to excellent yields and show a great tolerance towards an array of functional groups. Systematic variations of their basic structural motif have provided insights into the essential parameters responsible for catalytic activity which can be enhanced further by addition of Lewis or Bronsted acids, by irradiation with UV light, or by the adequate choice of the "non-coordinating" counterion X-. The latter turned out to play a particularly important role in determining the rate and selectivity of the reaction. A similarly pronounced influence is exerted by remote substituents on the allenylidene residue which indicates that this ligand (or a ligand derived thereof) may remain attached to the metal throughout the catalytic process. X-ray crystal structures of the catalytically active allenylidene complexes 3b.PF6 and 15.OTf as well as of the chelate complex 10 required for the preparation of the latter catalyst are reported.

Cationic Ruthenium Allenylidene Complexes as Catalysts for Ring Closing Olefin Metathesis

Cationic Ruthenium Allenylidene Complexes as Catalysts for Ring Closing Olefin Metathesis

Nucleophilic additions of anionic Group 6 carbene complexes on cationic indenyl–ruthenium(II) allenylidene derivatives: an easy entry to bimetallic complexes containing σ-alkynyl–carbene and vinylidene–carbene bridges †

The novel indenyl–ruthenium(II) allenylidene complexes [Ru{CCC(R)Ph}(η5-C9H7)(PPh3)L][PF6] (L = PMePh2, R = Ph 4a, H 4b; L = PMe2Ph, R = Ph 5) have been prepared by reaction of [RuCl(η5-C9H7)(PPh3)L] (L = PMePh22, PMe2Ph 3) with HCCC(OH)(R)Ph and NaPF6 in methanol. These allenylidene derivatives as well as [Ru{CCC(R)Ph}(η5-C9H7)(PPh3)2][PF6] (R = Ph 1a, H 1b) undergo regioselective nucleophilic additions of anionic Fischer type carbene complexes [Li][(CO)5M{C(OMe)CH2}] (M = Cr, W, Mo) at the Cγ atom of the unsaturated chain to afford the neutral bimetallic σ-alkynyl derivatives [Ru(CCC(R)Ph{CH2C(OMe)M(CO)5})(η5-C9H7)(PPh3)L] (L = PPh3, R = Ph, M = Cr 6a, W 6b, Mo 6c; L = PPh3, R = H, M = Cr 7a, W 7b; L = PMePh2, R = Ph, M = Cr 8a, W 8b; L = PMePh2, R = H, M = Cr 9a, W 9b; L = PMe2Ph, R = Ph, M = Cr 10a, W 10b). Protonation of these derivatives with HBF4·Et2O yields cationic vinylidene complexes [Ru(CC(H)C(R)Ph{CH2C(OMe)M(CO)5})(η5-C9H7)(PPh3)L][BF4] 11a–c, 12–15a,b which represent the first examples of bimetallic species containing a vinylidene–carbene bridge. Heating under reflux solutions of vinylidene complexes 11b and 12b in acetonitrile affords the carbene derivatives [(CO)5W{C(OMe)CH2C(R)Ph(CCH)}] (R = Ph 16a, H 16b) and the nitrile complex [Ru(NCMe)(η5-C9H7)(PPh3)2][BF4] 17. The diphenylallenylidene complex 1a regioselectively reacts with NaCN to yield the σ-alkynyl derivative [Ru{CCCPh2(CN)}(η5-C9H7)(PPh3)2] 18. Treatment of 18 with one equivalent of [M(CO)5(THF)] leads to the formation of the bimetallic σ-alkynyl complexes [Ru(CCCPh2{CN–M(CO)5})(η5-C9H7)(PPh3)2] (M = Cr 20a, W 20b, Mo 20c).

Coordinatively Unsaturated 16-Electron Ruthenium Allenylidene Complexes: Synthetic, Structural, and Catalytic Studies

The one-pot reactions of [(p-cymene)RuCl2]2 (1) or (PPh3)4RuCl2 (2) with 2 equiv of PCy3 and 3,3-diphenylpropyn-3-ol afford the novel 16-electron ruthenium allenylidene complex (PCy3)2Cl2Ru(CCCPh2) (3) in high yields. Substitution of one PCy3 ligand in 3 for one nucleophilic carbene ligand, IMes [1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene], affords the novel complex (PCy3)(IMes)Cl2Ru(CCCPh2) (4). Single-crystal X-ray structure analyses of complexes 3 and 4 were performed. Thermal stability of complexes 3 and 4 was investigated, and their catalytic activity promoting ring-closing metathesis (RCM) of various substrates was tested.

ChemInform Abstract: Coordinatively Unsaturated Ruthenium Allenylidene Complexes: Highly Effective, Well Defined Catalysts for the Ring‐Closure Metathesis of α,ω‐Dienes and Dienynes.

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Coordinatively unsaturated ruthenium allenylidene complexes: highly effective, well defined catalysts for the ring-closure metathesis of α,ω-dienes and dienynes

The well defined, conveniently accessible and coordinatively unsaturated allenylidene complexes [RuCl2(CC CPh2)(PCy3)2] and [Ru2Cl4(CCCPh2)(PCy3)(η-MeC6-H4Pri-4)] are highly effective catalysts for the ambient temperature ring-closure metathesis of α,ω-dienes and dienynes, illustrated by the facile and high yielding formation of variously functionalised 5, 6, 7, 8, 15, 16 and 18 membered mono- and bi-cyclic ring systems.