Arene Exchange Research Articles

Photochemical synthesis of new ( η6-arene)Cr–hydrido stannyl and ( η6-arene)Cr–bis-stannyl complexes. Ligand effects on the Sn–H interaction in the hydrido stannyl compounds

Hydrido stannyl compounds containing the η 2-H–SnPh 3 ligand and bis-stannyl compounds containing two SnPh 3 ligands have been obtained from the photolysis of ( η 6-arene)Cr(CO) 3 and HSnPh 3. New complexes with different arenes (mesitylene, trifluorotoluene and 1,4-dimethoxybenzene) have been obtained and characterized by X-ray diffraction: ( η 6-C 6H 4(OCH 3) 2)Cr(CO) 2(HSnPh 3) ( 3a), ( η 6-C 6H 4(OCH 3) 2)Cr(CO) 2(SnPh 3) 2 ( 3b). Structural data for 3a: monoclinic; space group P2 1/ c (No. 14); a=17.445(3), b=9.820(3) and c=16.302(5) Å; Z=4; V=2539.2(12) Å 3; 3b: monoclinic; space group P2 1/ n (No. 14); a=13.904(3), b=20.567(5) and c=13.911(3) Å; Z=4; V=3994(2) Å 3. 1H-NMR as well as X-ray provided evidence for the existence of three-center two-electron bonds in the hydrido stannyl complexes. The effects of different ligands on bonding and spectroscopic parameters were studied. Arene exchange reactions of the bis-stannyl complexes, as well as reactions of some of these compounds with P(C 2H 5) 3 and CO, were also investigated.

Acrylate-Assisted Arene-Chromium Bond Cleavage: Generation of a [Cr(CO)2 ] Fragment under Mild Conditions.

Displacement of the benzene ligand in 1 surprisingly occurs more readily than that of the methyl acrylate ligand. This paves the way for 1 to undergo arene exchange and arene substitution reactions, which may be triggered by a η2 →η4 haptotropic rearrangement of the acrylate. Complex 1 is thus a mild precursor of the highly unsaturated fragments [Cr(CO)2 ] (see scheme) and [Cr(CO)2 (η2 -acrylate)].

Oxidation-State-Dependent Reactivity and Catalytic Properties of a Rh(I) Complex Formed from a Redox-Switchable Hemilabile Ligand

The synthesis and characterization of a phosphinoalkylarene, redox-switchable hemilabile ligand (RHL), (η5-C5H5)Fe(η5-C5H4C6H4OCH2CH2PPh2) (1), are reported. This ligand, which incorporates a redox-active ferrocenyl group, exhibits oxidation-state-dependent bonding properties and, hence, affords electrochemical control over the electronic and steric environments of bound transition metal centers. Two equivalents of 1 complex to Rh(I) to yield a bis(phosphine), η6-arene complex [(η1:η6-(η5-C5H5)Fe(η5-C5H4C6H4OCH2CH2PPh2))(η1-(η5-C5H5)Fe(η5-C5H4C6H4OCH2CH2PPh2))Rh]+BF4- (2). Single-crystal X-ray diffraction studies of 2·1.25CH2Cl2, as well as solution spectroscopic data of 2, are consistent with this formulated piano-stool geometry. Foremost, the properties of 2 as a function of bound RHL state-of-charge are extensively investigated. Interestingly, 2D 1H NMR exchange spectroscopy (EXSY) studies demonstrate significantly faster intramolecular η6-arene, free arene exchange rates only upon oxidation of the lig...

Novel Hemilabile (Phosphinoalkyl)arene Ligands: Mechanistic Investigation of an Unusual Intramolecular, Arene−Arene Exchange Reaction

The novel, hemilabile (phosphinoalkyl)arene ligands ArX(CH2)2PPh2 (1a, Ar = C6H5, X = O; 1b, Ar = C6H5, X = CH2; 1c, Ar = FC6H4, X = CH2) were synthesized and complexed to Rh(I) to form the bis(phosphine), η6-arene piano stool complexes [(η6:η1-ArX(CH2)2PPh2)Rh(η1-ArX(CH2)2PPh2)]BF4 (2a−c). Complexes 2a−c were fully characterized in solution, and complex 2a was characterized by single-crystal X-ray diffraction methods. Two of these complexes, 2a,c, undergo an unusual, degenerate η6-arene, free arene exchange reaction which was studied by 2-D NMR EXSY experiments. A mechanism for the exchange reaction of 2a which involves the formation of a square planar, cis-phosphine, cis-ether Rh(I) complex, [Rh(η2-PhO(CH2)2PPh2)2]BF4 (13), is proposed.

MONO-η6-ARENE COMPLEXES OF CHROMIUM (II) AND CHROMIUM (0). ARENE EXCHANGE AND ARENE DISPLACEMENT REACTIONS OF η6-FLUOROARENE-DICARBONYLBIS (TRICHLOROSILYL) AND -TRICARBONYLCHROMIUM DERIVATIVES

Abstract In an attempt to obtain chromium-arene derivatives possessing high arene lability, (C6 H5F)Cr(CO)2 (SiCl3)2, (C6H4F2)Cr(CO)2(SiCl3)2, (C6H5F)Cr(CO)3, and (C6H4F2)Cr(CO)3 have been investigated. Kinetics of arene exchange have been studied showing that the Cr(II) derivatives exhibit ten-fold higher rates than the Cr(O) derivatives. Both electronic and steric effects appear to be important, although electronic effects dominate. Arene displacement by phosphine and phosphite ligands has also been studied. Although arene displacement took place, unexpected rearrangement and disproportionation reactions occurred yielding seven-coordinate (CO)4Cr(PR3)(SiCl3)2 species.

Thermal decomposition of (C 6Me 6)Ru(η 4-C 4Me 4S) and related reactivity and structural studies

The paper focuses on selected aspects of the chemical behavior of (C 6Me 6)Ru(η 4-C 4Me 4S) ( 1). Thermal decomposition of 1 in saturated hydrocarbon solutions yields the trinuclear product (C 6Me 6) 3Ru 3(C 4Me 4S) 2 ( 2a) which has been further characterized by single crystal X-ray diffraction. The molecule is centrosymmetric with two (C 6Me 6)Ru(C 4Me 4S) entities coordinated through their sulfur atoms to a central (C 6Me 6)Ru unit. When the thermolysis is conducted in aromatic solvents, we also observed products resulting from arene exchange such as (arene)C 6Me 6) 2Ru 3(C 4Me 4S) 2, where arene = C 6 D 6 ( 2b), toluene ( 2c). The (C 6Me 6) 3 and arene-exchange products are formed competitively, not consecutively. Compound 2a is protonated by NH 4PF 6 to give the hydride [(C 6Me 6) 3Ru 3(C 4Me 4S) 2H][PF 6] ([ 2aH]PF 6). Compound 2aH + is structurally dynamic in solution resulting from restricted rotation about the RuS axis. Compound 1 decomposes in the presence of H 2 to give the dinuclear dihydride (C 6Me 6) 2Ru 2(C 4Me 4S)H 2 ( 3), assigned an unsymmetrical structure where one (C 6Me 6)Ru center is bound to two hydrides and a sulfur atom, while the second (C 6Me 6)Ru is coordinated in an η 4-mode to the thiophene.

Arene Chromium and Manganese Tricarbonyl Analogs of the PCP Receptor Ligands 5-Methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801) and 10,5-(Iminomethano)-10,11-dihydro-5H-dibenzo[a,d]cycloheptene (IDDC)

Chromium tricarbonyl compleres of MK-801 (2), IDDC (4), and 3-Cl-IDDC (10) were prepared by arene exchange with benzenechromiumtricarbonyl. The resulting complexes relined binding affinity for the PCP receptor, as reflected by IC 50 values relative to [ 3 H]-2. A manganese tricarbonyl analog 28 of 4 was synthesized in which the D ring of 4 was replaced with cyclopentadienylmanganese tricarbonyl. However, 28 showed significantly diminished binding affinity for the PCP receptor, relative to 4. Attempts to prepare a ferrocene analog of 4 in which the A or D rings were replaced with ferrocene failed, due to a very stable carbocation formed in the last step of the synthetic route; the novel alcohols 25 and 29 were formed instead

Theoretical estimates of the η 6 bonding capability of buckminsterfullerene in transition metal complexes

In order to provide a quantitative description of the relative ability of C 60 to bond as an η 6 ligand, arene exchange energies for tricarbonyl(arene)chromium systems were calculated using the method of partial retention of diatomic differential overlap (PRDDO). This represents the first theoretical estimate of the relative affinity of C 60 as an η 6 ligand, and results indicate that C 60 is an inferior ligand compared to benzene. The arenes considered included benzene, chlorobenzene, p-difluorobenzene, and buckminsterfullerene. The exchange of benzene for C 60 as an arene ligand is calculated to require 19 kcal/mol, but this can be reduced by modifying the exchanging ligand. Reduced overlap from C 60 hybrid orbitals is found to be partly responsible for less favorable η 6 bonding, which suggests that larger metals such as tungsten may be better able to bond in an η 6 fashion to C 60.

Synthesis and reactivity of naphthalene sandwich complexes of molybdenum. X‐ray structure of [Mo(η6‐naphthalene) {P(OMe)3}3] and [Mo(H)(η6‐naphthalene){P(OMe)3}3][BF4

AbstractThe sandwich complexes bis(η6‐naphthalene)molybdenum(0) (1), bis(η6‐1‐methylnaphthalene)molybdenum(0) (2), and bis(η6‐1,4‐dimethylnaphthalene)molybdenum(0) (3) are synthesized by cocondensation of Mo‐atoms with the naphthalene ligands. Complexes 1–3 are also obtained by reduction of MoCl5 or MoCl4. 2THF with highly activated Mg in the presence of the naphthalene ligands. Mg was activated by sublimation of the metal in a simple rotating solution reactor. Complex 2 exists as a mixture of regio‐ and stereoisomers. Three regioisomers, 3a–c, are formed in reactions of Mo‐atoms with 1,4‐dimethylnaphthalene, whereas 3a, the isomer with the Mo‐atom coordinated to the unsubstituted rings, is formed selectively via the reductive method. The ligands in 1–3 are highly labile. CO displaces both naphthalene rings in 2 and 3 to give [Mo(CO)6], while PF3, P(OMe)3, and PMe3 displace only one coordinated naphthalene in 1 to yield the [Mo(η6‐naphthalene)L3] complexes 4–6. In toluene, arene exchange is a competitive process in reactions of 1 with PF3. Complexes 5 (L = P(OMe)3) and 6 (L = PMe3) react with HBF4 to give the cationic metal hydride complexes 8 and 9. The X‐ray crystal structures of [Mo(η6‐naphthalene) {P(OMe)3}3] (5) and [Mo(H)(η6‐naphthalene) {P(OMe)3}3][BF4] (8) are reported.

Tricarbonylchromium Phenyloxazoline and -Imine Complexes: Highly Regioselectiveortho-Additions of Carbon Nucleophiles

Alkyl-, vinyl- and aryllithium reagents and an ester enolate added efficiently and highly regioselectively ortho to the aromatic substituent of tricarbonyl(4,5-dihydro-4,4-dimethyl-2-phenyloxazole)chromium(0) (1) and tricarbonyl(benzylidene-cyclohexylamine)chromium(0) (2) complexes. The tertiary carbanion 2-lithio-2-methylpropionitrile gave a 3:1 para/meta selectivity. Complex 1 was obtained via arene exchange in tricarbonyl(naphthalene)chromium(0).

ChemInform Abstract: Arene Exchange by P Donors in the 19‐Electron Complexes FeICp(arene): Kinetics, Mechanism, and Salt Effects. Interconversion, Radical‐Type Reactions, and Electron‐Transfer Chemistry of the New 17‐Electron and 19‐Electron Radicals FeICpLn (L: Phosphine, Phosphite; n = 2, 3).

ChemInformVolume 21, Issue 41 Organoelement Compounds ChemInform Abstract: Arene Exchange by P Donors in the 19-Electron Complexes FeICp(arene): Kinetics, Mechanism, and Salt Effects. Interconversion, Radical-Type Reactions, and Electron-Transfer Chemistry of the New 17-Electron and 19-Electron Radicals FeICpLn (L: Phosphine, Phosphite; n = 2, 3). J. RUIZ, J. RUIZ Lab. Chim. Org. Organomet., CNRS, Univ. Bordeaux I, 33405 Talence, Fr.Search for more papers by this authorM. LACOSTE, M. LACOSTE Lab. Chim. Org. Organomet., CNRS, Univ. Bordeaux I, 33405 Talence, Fr.Search for more papers by this authorD. ASTRUC, D. ASTRUC Lab. Chim. Org. Organomet., CNRS, Univ. Bordeaux I, 33405 Talence, Fr.Search for more papers by this author J. RUIZ, J. RUIZ Lab. Chim. Org. Organomet., CNRS, Univ. Bordeaux I, 33405 Talence, Fr.Search for more papers by this authorM. LACOSTE, M. LACOSTE Lab. Chim. Org. Organomet., CNRS, Univ. Bordeaux I, 33405 Talence, Fr.Search for more papers by this authorD. ASTRUC, D. ASTRUC Lab. Chim. Org. Organomet., CNRS, Univ. Bordeaux I, 33405 Talence, Fr.Search for more papers by this author First published: October 9, 1990 https://doi.org/10.1002/chin.199041270AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume21, Issue41October 9, 1990 RelatedInformation

Arene exchange by phosphorus donors in the 19-electron complexes FeICp(arene): kinetics, mechanism, and salt effects. Interconversion, radical-type reactions, and electron-transfer chemistry of the new 17-electron and 19-electron radicals FeICpLn (L = phosphine, phosphite; n = 2, 3)

Arene exchange by phosphorus donors in the 19-electron complexes FeICp(arene): kinetics, mechanism, and salt effects. Interconversion, radical-type reactions, and electron-transfer chemistry of the new 17-electron and 19-electron radicals FeICpLn (L = phosphine, phosphite; n = 2, 3)

ChemInform Abstract: (Tetramethylthiophene)ruthenium Dichloride Dimer: A Versatile Synthetic Intermediate in Thiophene Coordination Chemistry.

AbstractThermal arene exchange in (I) yields the title dimer (III).

Indanetricarbonylchromium: the effects of 1- syn- and 1- anti substituents on the regioselectivity of nucleophilic addition. Crystal structures of 1- syn- and 1- anti- methoxyindanetricarbonylchromium

A series of diastereomeric syn and anti Cr(CO) 3 complexes of 1-substituted indanes have been prepared by thermolysis of Cr(CO) 6 or by arene exchange with naphthalene-Cr(CO) 3 ( 3). The regioselectivity of nucleophilic addition of α-nitrile carbon nucleophiles to syn and anti 1-R-indane Cr(CO) 3 complexes (R = OMe 4, Me 10) has been investigated and compared with that of analogous reactions with indaneCr(CO) 3 ( 1). The results of an X-ray study of syn- and anti- 4 are presented. Nucleophilic additions are shown to be sensitive to the steric and electronic effects of the benzylic substituent and the nucleophile. When the reaction mixtures are warmed to 0°C, equilibration of the regioisomeric cyclohexadienyl intermediates takes place.

Mechanism of arene exchange by phosphines and phosphites in the 19 electron complexes [FeICp(arene)], Cp =η5-C5H5, arene = C6H6 –nMen(n= 0,1)

A low temperature spectroscopic study of the facile arene exchange by phosphines and phosphites in the air-sensitive 19 electron complexes [FeICp(η6-arene)], (Cp = cyclopentadienyl, η5-C5H5), shows an associative pathway in the rate limiting step, which suggests a fast pre-equilibrium generating a 17 electron species.

Neighboring group participation in organometallic chemistry: anchimeric assistance in catalyzed arene exchange reactions of (diarylalkane)tricarbonylchromium complexes

Catalyse nucleophile de la migration du groupe Cr(CO) 3 d'un cycle a l'autre dans les derives diarylalcane. Comparaison avec la catalyse de l'echange externe. Formation d'un intermediaire ayant 3 groupes CO, une cetone et 2 arenes η 2

Stereoelectronic effects in arene exchange of (arene)tricarbonylchromium complexes: internal arene exchange and internal arene catalysis of external arene exchange

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStereoelectronic effects in arene exchange of (arene)tricarbonylchromium complexes: internal arene exchange and internal arene catalysis of external arene exchangeTeddy G. Traylor and Martin J. GoldbergCite this: Organometallics 1987, 6, 11, 2413–2416Publication Date (Print):November 1, 1987Publication History Published online1 May 2002Published inissue 1 November 1987https://doi.org/10.1021/om00154a023RIGHTS & PERMISSIONSArticle Views185Altmetric-Citations15LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (479 KB) Get e-Alerts Get e-Alerts

Transition-metal organometallic compounds. 8. Arene exchange reactions of bis(naphthalene)chromium

Synthese et caracterisation de (η 6 -arene)(η 6 -naphtalene)Cr et (μ-η 6 ,η 6 -naphtalene)bis(η 6 -benzene) dichrome. Spectres RMN de 1 H. Structure cristalline

Regioselective electrophilic substitution via lithiation and intramolecular arene exchange (haptotropic rearrangement) in (naphthalene)tricarbonylchromium

La reaction de (η 6 -naphtalene)Cr(CO) 3 avec (tetramethylpiperidyl) lithium et les electrophiles est hautement regioselective et donne des complexes (naphtalene substitue en 2)Cr(CO) 3 . Constantes de vitesse et parametres d'activation

ChemInform Abstract: Mechanisms of Arene Exchange in (Arene)tricarbonylchromium Compounds: Intermolecular and Intramolecular Exchanges in Complexes of Propenylbenzene, Stilbenes, and 1,1‐Diphenylethylene.

AbstractKinetic studies of arene exchange of (trans‐propenylbenzene)tricarbonyl‐Cr with benzene reveal intramolecular and intermolecular participation by the propenyl substituent.