Ruthenium-catalyzed isomerization of alkenes

Abstract

The present disclosure relates to a process for the isomerization of double-bond containing substrates into the corresponding isomerized product in which the target double-bond has been shifted to a position different from the original position using a certain organometallic ruthenium complex. Mixtures comprising the corresponding isomerized product may also be obtained.

Description

[0001] RUTHENIUM-CATALYZED ISOMERIZATION OF ALKENES

[0002] Field of the Disclosure

[0003] The present disclosure relates to the field of organic synthesis. More particularly, it provides a process for the isomerization of double-bond containing substrates into the corresponding isomerized product in which the target double-bond has been shifted to a position different from the original position using a suitable organometallic ruthenium complex. Mixtures comprising the corresponding isomerized product may also be obtained.

[0004] Background of the Disclosure

[0005] Alkenes are useful as versatile building blocks for the synthesis of a wide range of compounds, including perfumery ingredients or starting materials for the construction of more complex structures. From a broad perspective, carbon-carbon double bonds are seen as handles for the installation of new functionalities within a compound. Thus, the ability to control the position of carbon-carbon double bonds allows for further transformations or installation of new functionalities at a different position of the starting alkene. Some isomerization methods are known.

[0006] For example, WO 2005 / 061426 (Firmenich SA) describes a process for the carboncarbon double bond isomerization of a 2-alkyl-cyclohex-3-enyl alkyl or alkenyl ketone into a mixture comprising the corresponding 2-alkyl-cyclohex-2-enyl ketones and the corresponding 2-alkylene-cyclohexyl ketones, using a ruthenium precursor of the formula [Ru(diene)(allyl)2], [Ru(dienyl)2], [Ru(tetraene)(ene)] or [Ru(diene)(triene)] and an acid.

[0007] WO 2014114615 (Firmenich SA) describes the isomerization of acyclic exo double bonds using [Ru(CODyl)2H]BF4 in the preparation of 4-methylpent-3-en-1-ol derivatives. F. Bouachir, B. Chaudret, F. Dahan, F. Agbossou, I. Tkatchenko, Orga no meta I lies 1991, 10, 455-462, describes the isomerization of 1 -hexene to 2:3-hexene in a process catalyzed by [Ru(CODyl)2H]BF4.

[0008] WO 2022203964 (International Flavors & Fragrances) describes the ruthenium catalyzed isomerization of terminal double bonds of acyclic substrates to form internal alkenes at a temperature above 120°C.

[0009] CN108101760A (Wanhua Chemical Group Co Ltd) describes the formation of 2,6,6- trimethylcyclohex-2-ene-1-carbaldehyde, also known as a-cyclocitral, from 2,6,6- trimethylcyclohex-3-ene-1-carbaldehyde using a nickel(O) catalyst.

[0010] However, the isomerization of alkenes is not without challenges, particularly at industrial scale. One or more issues to tackle when implementing alkene isomerization at industrial scale include, but are not limited to, the need for stoichiometric amounts of costly or unavailable reagents, use of environmentally unfriendly solvents, low catalytic efficiency, low selectivity, or poor yields of desired products, to name a few. Further, low stability of some catalysts limits their use at large scale due to handling difficulties. In some cases, the need for an additive or high reaction temperatures may also preclude the use of some isomerization processes on sensitive substrates.

[0011] Therefore, there is an ongoing need for improved processes for the isomerization of double-bond containing substrates into the corresponding isomerized product in which the target double-bond has been shifted to a position different from the original position.

[0012] Summary of the Disclosure

[0013] The following aspects of the present disclosure seek to address one or more of the problems described hereinabove. In a first aspect, the present disclosure relates to a process for the isomerization of a compound having at least one double bond, the process comprising reacting the compound having at least one double bond with a compound of formula (I),

[0014] [(L1)Ru(L2)][X] (I), wherein

[0015] L1represents a dienyl ligand;

[0016] L2represents an arene;

[0017] X represents CIC ", R3SO3', wherein R3is Cl, F, Ci-Cs fluoroalkyl or fluoroaryl group; PFe', SbCle', AsCle', SbFe', AsFe', B(R4)4', wherein R4is F or an aryl group; thereby forming the corresponding isomerized compound.

[0018] In a second aspect, the present disclosure relates to a compound of formula (I),

[0019] [(L1)Ru(L2)][X] (I), wherein

[0020] L1represents a dienyl ligand;

[0021] L2represents an arene;

[0022] X represents CIC ", R3SO3', wherein R3is Cl, F, Ci-Cs fluoroalkyl or fluoroaryl group; PFe', SbCle', AsCle', SbFe', AsFe', B(R4)4', wherein R4is F or an aryl group; wherein the arene is selected from the group consisting of naphthalene, anthracene, phenanthrene, biphenyl, a compound represented by formula (II) wherein R5, R6, and R7are each, independently, H, a linear or branched Ci-Ce alkyl group, halogen, CN, C(O)R8, C(O)OR9, or OR10, wherein at least one of R5, R6, and R7is not H; wherein R8, R9, and R10are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, or a heteroatom-based covalent group, typically difluoroboranyl group (BF2); and a compound represented by formula (III) wherein X’ and X” are each, independently, CR11R12, C(O), O, NR13, S, S(O), or S(O)2, wherein R11, R12, and R13are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, and wherein n is 1 or 2.

[0023] Brief Description of the Figures

[0024] FIG. 1 shows complexes according to formula (I) having various L2ligands, and corresponding AMK (GC %) formed over time in an exemplary process according to the present disclosure.

[0025] FIG. 2 shows complexes according to formula (I) having various L2ligands, temperature, and corresponding AMK (GC %) formed over time in an exemplary process according to the present disclosure.

[0026] Detailed Description

[0027] As used herein, the terms “a”, “an”, or “the” means “one or more” or “at least one” unless otherwise stated. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of’ or “consist of’ the various components, substances and steps. As used herein the term “consisting essentially of’ shall be construed to mean including the listed components, substances or steps and such additional components, substances or steps which do not materially affect the basic and novel properties of the composition or method. In some embodiments, a composition in accordance with embodiments of the present disclosure that “consists essentially of’ the recited components or substances does not include any additional components or substances that alter the basic and novel properties of the composition.

[0028] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this specification pertains.

[0029] It should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of “1 to 10” is intended to include all sub-ranges between and including the recited minimum value of 1 and the recited maximum value of 10; that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10. Because the disclosed numerical ranges are continuous, they include every value between the minimum and maximum values. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations.

[0030] As used herein, and unless otherwise indicated, the term “about” or “approximately” means an acceptable error for a particular value as determined by one of ordinary skill in the art, which depends in part on how the value is measured or determined. In certain embodiments, the term “about” or “approximately” means within 1 , 2, 3, or 4 standard deviations. In certain embodiments, the term “about” or “approximately” means within 50%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, or 0.05% of a given value or range. Throughout the present disclosure, various chemical names and structures may be recited. Unless otherwise stated, any stereoisomers, such as enantiomers, diastereomers, anomers, epimers, and the like; and geometric isomers, such as cis / trans or E / Z isomers, of the recited chemical name or structure are contemplated. As would be understood by those of ordinary skill in the art, stereoisomers may possess one stereocenter, giving rise to enantiomers, or more than one stereocenter, giving rise to diastereomers, each stereocenter having one of two different stereochemistries (i.e. , R or S). Enantiomers may be characterized by their ability to rotate oncoming plane-polarized light to the right, designated as dextrorotatory, “(+)” or“D”, or to the left, designated as levorotatory, or“L”. Enantiomers may exist as racemic mixtures or scalemic mixtures. Geometric isomers refer to isomers in which the spatial relationship of atoms around a double bond are different, typically designated E or Z according to conventional understanding in the chemical art. Geometric isomers may also exist as mixtures of E and Z isomers. All of the aforementioned isomeric variations of the chemical names or structures recited herein are included.

[0031] As used herein, the terminology "(Cx-Cy)", “Cx-Cy”, or“Cx-y” in reference to an organic group, wherein x and y are each integers, means that the group may contain from x carbon atoms to y carbon atoms per group.

[0032] As used herein, the term "alkyl" means a monovalent straight or branched saturated hydrocarbon radical, more typically, a monovalent straight or branched saturated (Ci-C22)hydrocarbon radical, such as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, hexyl, octyl, hexadecyl, octadecyl, eicosyl, behenyl, tricontyl, and tetracontyl.

[0033] As used herein, the term "cycloalkyl" means a monovalent saturated cyclic hydrocarbon radical, more typically a saturated cyclic (C3-C22) hydrocarbon radical, such as, for example, cyclopropyl, cyclobutyl, cyclopentyl, cycloheptyl, cyclooctyl, and the like.

[0034] As used herein, the term "alkoxy" or “alkoxyl” refers to an O-alkyl radical, in which alkyl is as defined herein. Exemplary alkoxy groups, typically Ci-Ce alkoxy, include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tertbutoxy, pentoxy, and the like.

[0035] As used herein, the term "alkenyl" means an unsaturated straight or branched hydrocarbon radical, more typically an unsaturated straight, branched, (C2-C22) hydrocarbon radical, that contains one or more carbon-carbon double bonds, including, for example, ethenyl (vinyl), n-propenyl, and iso-propenyl, and allyl.

[0036] As used herein, the term "cycloalkenyl" means a monovalent cyclic hydrocarbon radical having at least one double bond, such as unsaturated cyclic (C3-C22) hydrocarbon radicals. Exemplary cycloalkenyl groups include, but are not limited to, cyclopentenyl, cyclopentadienyl, cyclohexenyl, cyclooctenyl, cyclooctadienyl, and the like.

[0037] As used herein, the term "aryl" means a monovalent unsaturated hydrocarbon radical containing one or more six-membered carbon rings in which the unsaturation may be represented by three conjugated double bonds. Aryl radicals include monocyclic aryl and polycyclic aryl. “Polycyclic aryl” refers to a monovalent unsaturated hydrocarbon radical containing more than one six-membered carbon ring in which the unsaturation may be represented by three conjugated double bonds wherein adjacent rings may be linked to each other by one or more bonds or divalent bridging groups or may be fused together. Aryl radicals may be substituted at one or more carbons of the ring or rings. Examples of aryl radicals include, but are not limited to, phenyl, methylphenyl, isopropylphenyl, tert-butylphenyl, methoxyphenyl, dimethylphenyl, trimethylphenyl, chlorophenyl, trichloromethylphenyl, triisobutyl phenyl, anthracenyl, naphthyl, phenanthrenyl, fluorenyl, and pyrenyl.

[0038] Any substituent or radical described herein may optionally be substituted at one or more carbon atoms with one or more, same or different, substituents described herein. For instance, an alkyl group may be further substituted with an aryl group or another alkyl group. Any substituent or radical described herein may also optionally be substituted at one or more carbon atoms with one or more substituents selected from the group consisting of halogen, such as, for example, F, Cl, Br, and I; nitro (NO2), cyano (CN), amino (NH2), and hydroxy (OH). As used herein, the term "haloalkyl" means an alkyl radical, more typically a (Ci- C22)alkyl radical, that is substituted with one or more halogen atoms, such as fluorine, chlorine, bromine, and iodine. Examples of haloalkyl groups include, but are not limited to, fluoroalkyl and chloroalkyl groups. Examples of fluoroalkyl groups include, for example, difluoromethyl, trifluoromethyl, perfluoroalkyl, 1 H,1 H,2H,2H- perfluorooctyl, perfluoroethyl, and -CH2CF3.

[0039] As used herein, the term "haloaryl" means an aryl radical that is substituted with one or more halogen atoms, such as fluorine, chlorine, bromine, and iodine. Examples of haloaryl groups include, but are not limited to, fluoroaryl and chloroaryl groups. Exemplary fluoroaryl groups include, but are not limited to, fluorophenyl, difluorophenyl, perfluorophenyl, and the like.

[0040] Throughout the present disclosure, various publications may be incorporated by reference. Should the meaning of any language in such publications incorporated by reference conflict with the meaning of the language of the present disclosure, the meaning of the language of the present disclosure shall take precedence, unless otherwise indicated.

[0041] In the first aspect, the present disclosure relates to a process for the isomerization of a compound having at least one double bond, the process comprising reacting the compound having at least one double bond with a compound of formula (I),

[0042] [(L1)Ru(L2)][X] (I), wherein

[0043] L1represents a dienyl ligand;

[0044] L2represents an arene;

[0045] X represents CIOT, R3SC>3', wherein R3is Cl, F, Ci-Cs fluoroalkyl or fluoroaryl group; PFe’, SbCle', AsCle', SbFe', AsFe', B(R4)4', wherein R4is F or an aryl group; thereby forming the corresponding isomerized compound. The compound of formula (I) is a ruthenium-based complex used to facilitate the isomerization reaction of the present disclosure. L1and L2represent the requisite ligands coordinated to the ruthenium center.

[0046] L1represents a dienyl ligand derived from linear or branched C4-C15 or cyclic C7-C20 dienes. In some embodiments, the dienyl ligand is derived from a linear or branched C7-C12, typically C7-C10, hydrocarbon compound comprising two carbon-carbon double bonds, and may be optionally substituted. Exemplary dienes include, but are not limited to, 1 ,5-cyclooctadiene, 1 ,3-cyclooctadiene, norbornadiene (NBD), 1 ,4- heptadiene, 2,3,4-trimethylpenta-1 ,3-diene, 2,4-dimethylpenta-2,4-diene, 2,4- cycloheptadiene, 1 ,4-heptadiene, and mixtures thereof. The dienyl ligand may be characterized by its hapticity, which would be understood by those of ordinary skill in the art as the number of atoms involved in the metal bonding interaction and is typically indicated by the formula with the qnor eta-n notation in which n represents the number of atoms involved in the metal bonding interaction. In an embodiment, L1is an eta-5 dienyl ligand. In an embodiment, L1is an eta-5 dienyl ligand derived from a diene selected from the group consisting of 1 ,3- cyclooctadiene, 1 ,5- cyclooctadiene (COD), 2,4-dimethylpenta-2,4-diene, 2,3,4-trimethylpenta-1 ,3-diene, 2,4-dimethyl-1-oxa-2,4-pentadiene, 2,4-cycloheptadiene, and 1 ,4-heptadiene. In an embodiment, L1is an eta-5 dienyl ligand derived from 1 ,3-cyclooctadiene or 1 ,5- cyclooctadiene (COD).

[0047] L2represents an arene ligand. As used herein, an arene is an unsaturated hydrocarbon containing one or more six-membered carbon rings in which the unsaturation may be represented by three conjugated double bonds. Arenes may be monocyclic or polycyclic. Polycyclic arenes refer arenes containing more than one six-membered carbon ring in which the unsaturation may be represented by three conjugated double bonds wherein adjacent rings may be linked to each other by one or more bonds or divalent bridging groups or may be fused together. Arenes may be substituted at one or more carbons of the ring or rings. Arenes may be fused to other types of rings, such as cycloalkyl rings. Exemplary arenes include, but are not limited to, benzene, naphthalene, anthracene, phenanthrene, biphenyl, fluorenyl, pyrenyl, and derivatives thereof. In an embodiment, the arene is selected from the group consisting of benzene, naphthalene, anthracene, phenanthrene, biphenyl, and derivatives thereof. In an embodiment, the arene is not benzene or toluene (methylbenzene). In an embodiment, the arene is selected from the group consisting of benzene derivative, naphthalene, anthracene, phenanthrene, biphenyl, and derivatives thereof, with the proviso that the arene is not toluene.

[0048] As used herein, the term “derivative” when used in reference to an arene refers to a compound in which one or more C-H moieties have been replaced with a C-R moiety, a C=O moiety, or a heteroatom, wherein R is a non-hydrogen substituent, or has been partially reduced or oxidized. Exemplary R groups include, but are not limited to, heteroatom-based covalent groups, such as those described herein, C(O)R’, C(O)OR”, or OR ’, where R’, R”, and R’” are independently H, alkyl groups, or heteroatom-based covalent groups, such as those described herein. Where two or more C-H moieties have been replaced with C-R moieties, the R substituents may together form a ring, which can vary in degree of saturation and may also include C=O moieties and / or heteroatoms. Exemplary benzene derivatives include, but are not limited to chlorobenzene, 1 ,3,5-trimethylbenzene, 1 ,3,5-trimethoxybenzene, 1 ,2,3-benzenetriol, acetophenone (acetylbenzene), methyl benzoate (methyl benzene carboxylate), ethyl benzoate (ethyl benzene carboxylate), benzaldehyde (benzene carboxaldehyde), 1 -indanone, phtalide, and any mixture thereof. Exemplary naphthalene derivatives include, but are not limited to, 1 -acetonaphtone (1-acetylnaphtalene), 1-tetralone (1-oxo-1 ,2,3,4-tetrahydronaphthalene), and any mixture thereof.

[0049] In an embodiment, the arene is an arene represented by formula (II) wherein R5, R6, and R7are each, independently, H, a linear or branched Ci-Ce alkyl group, halogen, CN, C(O)R8, C(O)OR9, or OR10, wherein R8, R9, and R10are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, or a heteroatom-based covalent group, typically difluoroboranyl group (BF2).

[0050] As used herein, a heteroatom-based covalent group refers to a substituent comprising at least one heteroatom and the heteroatom is covalently bonded to the substituted atom in a molecule. Exemplary heteroatom-based covalent groups include, but are not limited to, boranyl, such as difluoroboranyl (BF2), boronic acid (B(OH)2), boronic ester (B(OR)2), halogen, such as, for example, F, Cl, Br, and I; nitro (NO2), amino (NH2), hydroxy (OH), alkoxy (OR), thiol (SH), thioether (SR), and the like. In an embodiment, the heteroatom-based covalent group is difluoroboranyl group (BF2).

[0051] In an embodiment, the at least one of R5, R6, and R7is not H. In another embodiment, at least two of R5, R6, and R7are not H. In yet another embodiment, R5, R6, and R7are not H.

[0052] In an embodiment, R5, R6, and R7are each, independently, a linear or branched Ci- Ce alkyl group or OR10, wherein R10is a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group.

[0053] In an embodiment, R5and R6are each H, and R7is a linear or branched Ci-Ce alkyl group, C(O)R8, or C(O)OR9, wherein R8and R9are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, or a heteroatom-based covalent group, typically difluoroboranyl group (BF2).

[0054] In another embodiment, R5, R6, and R7are each, independently, methyl or methoxy.

[0055] In yet another embodiment, R5and R6are each H and R7is methyl, C(O)R8, or C(O)OR9, wherein R8and R9are each, independently, H, methyl or ethyl group, or a difluoroboranyl group (BF2).

[0056] In an embodiment, the arene is an arene represented by formula (III) wherein X’ and X” are each, independently, CR11R12, C(0), O, NR13, S, S(O), or S(O)2, wherein R11, R12, and R13are each, independently, H, or a linear or branched C1-C6 alkyl group, typically methyl or ethyl group, and wherein n is 1 or 2.

[0057] In an embodiment, X’ is C(O) and X” is O.

[0058] In an embodiment, the arene is selected from the group consisting of ethyl benzoate, acetophenone, toluene, mesitylene, 1 ,3,5-trimethoxybenzene, phthalide, 1 -indanone, 1-tetralone, and any combination thereof.

[0059] X represents a counterion, which may be CIO4; R3SC>3', wherein R3is Cl, F, Ci-Cs fluoroalkyl or fluoroaryl group; PFe’, SbCle', AsCle', SbFe', AsFe', B(R4)4', wherein R4is F or an aryl group. In an embodiment, X is B(R4)4', wherein R4is F or an aryl group. In another embodiment, X is BF4'.

[0060] The amount of the compound of formula (I) used in the isomerization process described herein is not particularly limited. However, in an embodiment, the compound of formula (I) is present in a catalytic amount. In another embodiment, the compound of formula (I) is present in an amount of from 0.0010 mol% to 0.40 mol%, typically 0.0025 mol% to 0.20 mol%, more typically 0.01 mol% to 0.15 mol%, relative to the molar amount of the compound having at least one double bond, i.e. , compound to be isomerized.

[0061] Optionally, the process of the present disclosure may be conducted using a nonaromatic weakly- or non-coordinating solvent. As used herein, a non-coordinating or weakly coordinating solvent is a solvent which does not significantly deactivate the catalyst and allows the substrate to interact with the catalyst, which is a concept well- known to those ordinary skill in the art of catalysis. In other words, a weakly- or non- coordinating solvent is a solvent which does not coordinate at all the Ru center of the catalyst, or which has a coordination stability constant inferior to that of the substrate to be isomerized. In general, any solvent that is inert under the experimental conditions and can solubilize the substrate and catalyst is particularly suitable. In an embodiment, the process is carried out in the presence of a non-aromatic weakly- or non-coordinating solvent selected from the group consisting of a chlorinated hydrocarbon, a saturated or unsaturated hydrocarbon, an ether, an ester, a weakly coordinating ketone (sterically hindered ketone), and mixtures thereof. In an embodiment, the non-aromatic weakly- or non-coordinating solvent is selected from the group consisting of CH2CI2, heptane, octane, dibutyl ether, diethyl ether, butyl acetate, methyl tert-butyl ether, diisopropylketone, and mixtures thereof. In an embodiment, the process is carried out in the absence of any solvent.

[0062] The process of the present disclosure as mentioned is carried out under an inert, or an essentially oxygen free atmosphere. A person of ordinary skill in the art knows what is meant by an inert atmosphere, and as non-limiting examples of such atmosphere, one may cite a nitrogen or argon atmosphere.

[0063] The process may be conducted over a broad range of temperatures. A person of ordinary skill in the art would be able to select the suitable temperature as a function of the melting and boiling point as well as of the specific properties of any solvents used as well as the desired time of reaction or conversion. However, in an embodiment, the process is conducted at a temperature of from 45 to 150 °C, typically from 90 to 135 °C, more typically 100 to 135 °C. In another embodiment, the process is conducted at a temperature of from 115 to 125 °C.

[0064] The compound having at least one double bond acts as the substrate to be isomerized. According to the present disclosure, the position of the target at least one double bond is shifted to a position different from the original position. Typically, the position of the target at least one double bond is shifted to an adjacent position. The substrate is not particularly limited. However, in an embodiment, the compound having at least one double bond is a compound of formula (IV),

[0065] wherein p is 0 to 12, typically 1 to 12;

[0066] R14represents a hydrogen atom, linear or branched Ci-Ce alkyl, C2-C6 alkenyl group, Ci-Ce alkoxy group, Ci-Ce cycloalkyl, C2-C6 cycloalkenyl group, or aryl; A represents C=O or C(Ra)2, wherein Rais, at each occurrence, independently, a hydrogen atom or a linear or branched Ci-Ce alkyl group or a Ci-Ce alkoxy group;

[0067] R15, R16, R17, and R18at each occurrence, represents, independently, hydrogen atom, linear or branched Ci-Ce alkyl, C2-C6 alkenyl group, Ci-Ce alkoxy group, Ci-Ce cycloalkyl, C2-C6 cycloalkenyl group, or aryl; or R16and R17together with the carbon atoms to which they are attached form a carbocyclic or heterocyclic ring; or, alternatively, R18and R15together with the carbon atoms to which they are attached form a carbocyclic or heterocyclic ring; or, alternatively, R17and R14together with the carbon atoms to which they are attached form a carbocyclic or heterocyclic ring.

[0068] In an embodiment, the compound of formula (IV) is a compound of formula (IVb) wherein A, R14to R18are as defined, and R19at each occurrence, represents, independently, hydrogen atom, linear or branched Ci-Ce alkyl, C2-C6 alkenyl group, C1-C6 alkoxy group, Ci-Ce cycloalkyl, C2-C6 cycloalkenyl group, or aryl.

[0069] In some embodiments, the isomerization of a compound having at least one double bond results in a mixture comprising the target corresponding isomerized product in combination with one or more other isomerized products. Such mixtures are contemplated by the present disclosure.

[0070] In an embodiment, the corresponding isomerized compound comprises a compound of formula (V) wherein A, R14to R19are as defined. In some embodiments, the isomerization reaction results in a mixture comprising a compound of formula (V) in combination with one or more other isomerized products.

[0071] Upon reaction completion, the desired products may be isolated using methods known to those of ordinary skill in the art. For example, water may be added to the reaction mixture to quench the catalyst and the lower aqueous phase removed. The organic phase may then be washed several times with water, dried, typically with a drying agent, such as anhydrous sodium sulfate, filtered, and then concentrated. Optionally, after solvent concentration, flash distillation under vacuum may be performed.

[0072] In the second aspect, the present disclosure relates to a compound of formula (I), [(L1)Ru(L2)][X] (I), wherein

[0073] L1represents a dienyl ligand;

[0074] L2represents an arene;

[0075] X represents CIO4; R3SC>3', wherein R3is Cl, F, Ci-Cs fluoroalkyl or fluoroaryl group; PFe’, SbCle', AsCle', SbFe', AsFe', B(R4)4', wherein R4is F or an aryl group; wherein the arene is selected from the group consisting of naphthalene, anthracene, phenanthrene, biphenyl, a compound represented by formula (II) wherein R5, R6, and R7are each, independently, H, a linear or branched Ci-Ce alkyl group, halogen, CN, C(O)R8, C(O)OR9, or OR10, wherein at least one of R5, R6, and R7is not H; wherein R8, R9, and R10are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, or a heteroatom-based covalent group, typically difluoroboranyl group (BF2); and a compound represented by formula (III) wherein X’ and X” are each, independently, CR11R12, C(O), O, NR13, S, S(O), or S(O)2, wherein R11, R12, and R13are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, and wherein n is 1 or 2. The elements or features of the process of the first aspect may be applied to subject matter of the second aspect related to the compounds of formula (I) per se, mutatis mutandis.

[0076] The complex according to formula (I) may be synthesized according to a suitable method comprising: a) providing a complex of the formula [((q5- cyclooctadienyl)2RuH][X], and b) reacting the complex provided in step a) with an arene described herein. In an embodiment, the arene is selected from the group consisting of naphthalene, anthracene, phenanthrene, biphenyl, a compound represented by formula (IV) wherein R5, R6, and R7are each, independently, H, a linear or branched Ci-Ce alkyl group, halogen, CN, C(O)R8, C(O)OR9, or OR10, wherein at least one of R5, R6, and R7is not H; wherein R8, R9, and R10are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, or a heteroatom-based covalent group, typically difluoroboranyl group (BF2); and a compound represented by formula (V) wherein X’ and X” are each, independently, CR11R12, C(O), O, NR13, S, S(O), or S(O)2, wherein R11, R12, and R13are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, and wherein n is 1 or 2. The starting complex of the formula [((q5-cyclooctadienyl)2RuH][X] may be synthesized according to methods known to those of ordinary skill in the art. For example, a suitable procedure is described in F. Bouachir, B. Chaudret, F. Dahan, F. Agbossou, I. Tkatchenko, Organometallics 1991 , 10, 455-462, which is incorporated herein by reference, in which the starting complex is obtained from the reaction of Ru(COD)(COT) and HBF4.Et2O. In another suitable procedure, the starting complex is obtained by the reaction of Ru(COD)(methylallyl)2 with BF3.(CH3COOH)2, as described in WO 2014 / 114615, which is incorporated herein by reference. In step b), the complex obtained in step a) is reacted with the arene. Steps a) and b) may be performed separately, i.e., the complex of the formula [((q5- cyclooctadienyl)2RuH][X] is isolated and then reacted with the arene in step b), or may be conducted in one-pot. In some embodiments, the complex may be highly sensitive. Therefore, a one-pot procedure is advantageous because the complex may be prepared without isolation and handling of the complex of the formula [((q5- cyclooctadienyl)2RuH][X],

[0077] Mention is made of the use of the complexes according to formula (I) for the isomerization of a compound having at least one double bond to a corresponding isomerized compound.

[0078] The processes and catalysts according to the present disclosure are further illustrated by the following non-limiting examples.

[0079] Examples

[0080] Unless otherwise indicated, the following general procedure was used for the isomerization reaction. Solid [(eta-5 dienyl)Ru(arene)][X] complex was placed in a Schlenk tube. It was degassed by performing vacuum / nitrogen cycles (3 times). Previously inerted substrate was then loaded under nitrogen atmosphere in the same Schlenk tube and the reaction mixture was degassed by performing vacuum / nitrogen cycles under stirring (three times). It was then heated to the desired temperature while being maintained under nitrogen atmosphere during the whole reaction. Reaction progress was followed by GC analysis upon sampling under nitrogen atmosphere. Upon reaction completion, the Schlenk tube was cooled down to 20°C.

[0081] Example 1

[0082] Ruthenium complexes of formula [(q5-cyclooctadienyl)Ru(L2)][BF4] in which the L2ligand was varied were used to conduct the isomerization reaction to rac-1-((1 R,2S)- 2,6,6-trimethylcyclohex-3-en-1-yl)ethan-1-one (“trans delta methyl ketone” or “TDMK”) to 1-(2,6,6-trimethylcyclohex-2-en-1-yl)ethan-1-one (“AMK”) according to the general procedure described herein.

[0083] The solid ruthenium complexes of formula [(q5-cyclooctadienyl)Ru(L2)][BF4] were prepared as follows. Solid [(q5-cyclooctadienyl)2RuH][BF4] was placed in a Schlenk tube. It was degassed by performing vacuum / nitrogen cycles (3 times). Previously inerted dry CH2CI2 (2.5 mL / mmol. of Ru) was then added under inert atmosphere to the ruthenium complex and the obtained yellow-brown solution was degassed performing vacuum / nitrogen cycles. Previously inerted anhydrous arene (L2) (1 .2-2.0 mol. eq. / Ru depending on the nature of the arene) was then slowly added at room temperature to the stirred reaction mixture reaction mixture which was left stirring under those conditions for 16 hours. Et20 (7.5 mL / Ru mmol.) was then slowly added for product precipitation that was filtered under inert atmosphere, further washed with a 3 / 1 Et2O / CH2Cl2 mixture (3 times 2.5 mL / mmol. of Ru) and then Et20 (1 time 2.5 mL / mmol. of Ru) and then dried under vacuum.

[0084] The complex was used in an amount resulting in 0.1 mol% Ru, relative to the substrate TDMK. The reaction was carried out neat at a temperature of 120 °C. FIG. 1 shows the different L2ligands used, and corresponding AMK (GC %) formed over time. Yields of up to 88% (by GC) AMK were obtained.

[0085] Example 2.

[0086] The isomerization reaction of Example 1 was carried out, except that the temperature used was 90 °C or 120 °C. FIG. 2 shows the ligands, temperature, and corresponding AMK (GC %) formed over time. Yields of up to 88% (by GC) AMK were obtained.

[0087] Example 3.

[0088] Further [(r|5-2,4-cyclooctadien-1-yl)Ru((r|6-arene)][BF4] complexes have been synthesized according to the following general procedure:

[0089] [Ru[(r|5-2,4-cyclooctadien-1-yl)2H][BF4] (1 eq.) was weighed out in a dry and clean Schlenk tube which was then made inert through vacuum / nitrogen cycles. Dry and inert CH2CI2 (2.5 mL / mmol.) was then added to the solid ruthenium precursor at 20°C under inert atmosphere. Dry and inert arene (2 eq. with respect to ruthenium) was then slowly added stirring at 20°C under inert atmosphere and reaction mixture was left under such conditions for 16 hours. CH2CI2 was then partly concentrated at 20°C under vacuum until product precipitation that was then further precipitated upon Et2O addition. The obtained suspension was then filtered under nitrogen and the remaining solid was washed with some CFhCh^O mixture and then Et2O before being dried under high vacuum for several hours to afford desired products described below in 92-99% yields.

[0090] [(r|5-2,4-cyclooctadien-1-yl)Ru(r|6-methylbenzoate)][BF4]:

[0091] It was obtained according to the above-described general procedure as a yellowish tan solid in 95% yield.

[0092] 1H NMR (400 MHz, CD2CI2): 56.86-6.81 (m, 2H, 2 CH Ar), 6.69 (t, J = 6.6 Hz, 1 H, =CH), 6.45-6.40 (m, 1 H, CH Ar), 6.39-6.34 (m, 2H, 2 CH Ar), 4.89 (ddd, J = 9.0, 6.6, 1 .6 Hz, 2H, 2 =CH), 4.46 (dt, J = 9.0, 3.6 Hz, 2H, 2 =CH), 4.02 (s, 3H, CH3), 1 .96 (dm, J = 16.6 Hz, 2H, 2 CH2), 1.36 (ddt, J = 16.6, 13.6, 3.2 Hz, 2H, 2 CH2), 1.28 (dm, J = 13.6 Hz, 1 H, CH2), 0.08 ppm (qt, J = 13.6, 2.6 Hz, 1 H, CH2).

[0093] 13C NMR (101 MHz, CD2CI2): 5 165.0 (CO), 108.6 (=CH), 94.8 (2 CH Ar), 94.4 (2 CH Ar), 93.9 (CH Ar), 91 .7 (C Ar), 84.3 (2 =CH), 61 .0 (2 =CH), 54.2 (CH3), 28.4 (2 CH2), 18.9 (CH2). [(r|5-2,4-cyclooctadien-1-yl)Ru(r|6-naphtalene)][BF4]:

[0094] It was obtained according to the above-described general procedure as an orange solid in 98% yield.

[0095] 1H NMR (500 MHz, CD2CI2): 5 7.82-7.74 (m, 4H, 4 CH Ar), 6.83-6.79 (m, 2H, 2 CH Ar), 6.43-6.39 (m, 2H, 2 CH Ar), 6.30 (t, J = 6.6 Hz, 1 H, =CH), 4.44 (ddd, J = 9.0, 6.6, 1.6 Hz, 2H, 2 =CH), 4.12 (dt, J = 9.0, 3.6 Hz, 2H, 2 =CH), 1.65 (dm, J = 16.6 Hz, 2H, 2 CH2), 1.06-0.95 (m, 3H, 3 CH2), -0.26 ppm (qt, J = 13.6, 2.6 Hz, 1 H, CH2)

[0096] 13C NMR (126 MHz, CD2CI2): 5 132.6 (2 CH Ar), 128.7 (2 CH Ar), 106.6 (=CH), 103.7 (2 C Ar), 94.5 (2 CH Ar), 90.4 (2 CH Ar), 82.8 (2 =CH), 60.5 (2 =CH), 27.7 (2 CH2), 18.8 (CH2).

[0097] [(r|5-2,4-cyclooctadien-1-yl)Ru(r|6-1-acetonaphtone)][BF4]:

[0098] It was obtained according to the above-described general procedure as a bright yellow orange solid in 99% yield.

[0099] 1H NMR (400 MHz, CD2CI2): 8 8.39 (dd, J = 7.2, 1 .0 Hz, 1 H, CH Ar), 8.08 (d, J = 8.6 Hz, 1 H, CH Ar), 7.86 (dd, J = 8.6, 7.2 Hz, 1 H, CH Ar), 7.73 (d, J = 7.2 Hz, 1 H, CH Ar), 6.79 (dd, J = 6.2, 1 .0 Hz, 1 H, CH Ar), 6.52 (td, J = 6.2, 1 .0 Hz, 1 H, CH Ar), 6.48 (td, J = 6.2, 1 .0 Hz, 1 H, CH Ar), 6.28 (t, J = 6.8 Hz, 1 H, 1 =CH), 4.60 (ddd, J = 8.0, 6.8, 1 .6 Hz, 1 H, =CH), 4.52 (ddd, J = 8.0, 6.8, 1 .6 Hz, 1 H, =CH), 4.33 (dt, J = 9.0, 3.6 Hz, 1 H, =CH), 4.26 (dt, J = 9.0, 3.6 Hz, 1 H, =CH), 2.79 (s, 3H, CH3), 1 .66 (dm, J = 16.6 Hz, 2H, 2 CH2), 1.02 (dm, J = 13.6 Hz, 1 H, CH2), 0.93 (ddt, J = 16.6, 13.6, 3.0 Hz, 2H, 2 CH2), -0.25 ppm (qt, J = 13.6, 2.6 Hz, 1 H, CH2)

[0100] 13C NMR (101 MHz, CD2CI2): 8 199.9 (CO), 136.3 (CH Ar), 134.8 (CH Ar), 134.2 (C Ar), 130.9 (CH Ar), 106.8 (=CH), 103.0 (C Ar), 100.8 (C Ar), 95.3 (CH Ar), 95.1 (CH Ar), 91 (CH Ar), 87.9 (CH Ar), 83.6 (=CH), 82.8 (=CH), 61.2 (=CH), 60.9 (=CH), 29.5 (CH3), 27.8 (2 CH2), 18.7 (CH2). [(iq5-2,4-cyclooctadien-1-yl)Ru(iq6-1 ,2,3-benzenetriol)][BF4]:

[0101] It was obtained according to the above-described general procedure as a very pale green solid in 94% yield.

[0102] 1H NMR (500 MHz, d8-THF): 5 9.53 (br s, 3H, 3 OH), 6.31 (t, J = 6.6 Hz, 1 H, =CH),

[0103] 5.91 (d, J = 6.0 Hz, 2H, 2 CH Ar), 5.73 (t, J = 6.0 Hz, 1 H, CH Ar), 4.55 (br t, J = 8.0 Hz, 2H, 2 =CH), 3.89 (dt, J = 9.0, 3.6 Hz, 2H, 2 =CH), 1 .88 (dm, J = 16.0 Hz, 2H, 2 CH2), 1.46 (ddt, J = 16.0 Hz, 13.6, 2.8 Hz, 2H, 2 CH2), 1.19 (dm, J = 13.6 Hz, 1 H, CH2), 0.04 (qt, J = 13.6, 2.8 Hz, 1 H, CH2).

[0104] 13C NMR (126 MHz, ds-THF): 8 128.8 (2 C Ar), 118.1 (C Ar), 106.8 (=CH), 86.5 (CH Ar), 82.8 (2 =CH), 78.1 (2 CH Ar), 58.6 (2 =CH), 29.1 (2 CH2), 20.6 (CH2).

[0105] [(iq5-2,4-cyclooctadien-1-yl)Ru 1,3,5-trimethoxybenzene)][BF4]:

[0106] It was obtained according to the above-described general procedure as a light beige solid in 92% yield.

[0107] 1H NMR (400 MHz, CD2CI2): 86.32 (t, J = 6.6 Hz, 1 H, =CH), 5.90 (s, 3H, 3 CH Ar),

[0108] 4.92 (br t, J = 7.8 Hz, 2H, 2 =CH), 3.61 (dt, J = 8.8, 3.6 Hz, 2H, 2 =CH), 2.00 (dm, J = 16.0 Hz, 2H, 2 CH2), 1 .56 (ddt, J = 16.0, 13.4, 3.0 Hz, 2H, 2 CH2), 1 .30 (dm, J = 13.4 Hz, 1 H, CH2), 0.09 (qt, J = 13.4, 2.8 Hz, 1 H, CH2).

[0109] 13C NMR (101 MHz, CD2CI2): 8 138.6 (3 C Ar), 103.4 (=CH), 82.4 (2 =CH), 66.9 (3 CH Ar), 61 .5 (2 =CH), 58.1 (3 CH3), 29.3 (2 CH2), 19.8 (CH2).

[0110] [(r|5-2,4-cyclooctadien-1-yl)Ru(r|6-1-indanone)][BF4]:

[0111] It was obtained according to the above-described general procedure as a beige yellow solid in 98% yield.

[0112] 1H NMR (400 MHz, CD2CI2): 86.64 (t, J = 7.0 Hz, 1 H, =CH), 6.48 (d, J = 5.6 Hz, 1 H, CH Ar), 6.46 (d, J = 5.6 Hz, 1 H, CH Ar), 6.41 (td, J = 5.6, 1.0 Hz, 1 H, CH Ar), 6.34 (td, J = 5.6, 1 .0 Hz, 1 H, CH Ar), 4.94 (br t, J = 9.0 Hz, 2H, 2 =CH), 4.35 (dt, J = 9.0, 3.6 Hz, 1 H, =CH), 4.05 (dt, J = 9.0, 3.6 Hz, 1 H, =CH), 3.42 (ddd, J = 18.0, 8.6, 5.0 Hz, 1 H, CH2), 3.24 (ddd, J = 18.0, 8.6, 2.6 Hz, 1 H, CH2), 2.90 (ddd, J = 20.0, 8.6, 2.6 Hz, 1 H, CH2), 2.71 (ddd, J = 20.0, 8.6, 5.0 Hz, 1 H, CH2), 2.00-1 .89 (m, 2H, 2 CH2), 1.42-1.22 (m, 3H, 2 CH2), 0.07 (qt, J = 13.8, 2.6 Hz, 1 H, CH2).

[0113] 13C NMR (101 MHz, CD2CI2): 8 203.0 (CO), 123.8 (C Ar), 107.6 (=CH), 96.9 (C Ar), 94.8 (CH Ar), 94.2 (CH Ar), 91 .7 (CH Ar), 88.3 (CH Ar), 85.3 (=CH), 84.5 (=CH), 64.3 (=CH), 62.4 (=CH), 35.8 (CH2), 28.1 (CH2), 27.8 (CH2), 24.8 (CH2), 19.0 (CH2).

[0114] [(iq5-2,4-cyclooctadien-1-yl)Ru(q6-1-tetralone)][BF4]:

[0115] It was obtained according to the above-described general procedure as a beige yellow solid in 95% yield.

[0116] 1H NMR (500 MHz, CD2CI2): 86.62 (t, J = 6.8 Hz, 1 H, =CH), 6.48-6.45 (m, 1 H, CH Ar), 6.43-6.37 (m, 2H, 2 CH Ar), 6.08-6.05 (m, 1 H, CH Ar), 4.94 (ddd, J = 9.0, 6.8, 1.6 Hz, 2H, 2 =CH), 4.28 (dt, J = 9.0, 3.6 Hz, 1 H, =CH), 4.13 (dt, J = 9.0, 3.6 Hz, 1 H, =CH), 3.19 (ddd, J = 17.2, 11.2, 4.4 Hz, 1 H, CH2), 2.97 (dtd, J = 17.2, 4.4, 1.2 Hz, 1 H, CH2), 2.89 (dtd, J = 17.2, 4.6, 1.2 Hz, 1 H, CH2), 2.73 (ddd, J = 17.2, 12.6, 4.6 Hz, 1 H, CH2), 2.36 (oct, J = 4.6 Hz, 1 H, CH2), 2.20-2.09 (m, 1 H, CH2), 2.02-1 .91 (m, 2H, 2 CH2), 1.48 (ddt, J = 16.8, 13.6, 2.8 Hz, 1 H, CH2), 1.38-1.25 (m, 3H, 2 CH2), 0.11 (qt, J = 13.6, 2.8 Hz, 1 H, CH2).

[0117] 13C NMR (126 MHz, CD2CI2): 8 196.6 (CO), 117.0 (C Ar), 107.6 (=CH), 94.7 (2 CH Ar), 93.2 (C Ar), 92.4 (CH Ar), 89.3 (CH Ar), 84.4 (=CH), 84.2 (=CH), 63.8 (=CH), 62.5 (=CH), 39.1 (CH2), 28.6 (CH2), 28.2 (CH2), 28.0 (CH2), 22.5 (CH2), 19.0 (CH2).

[0118] [(r|5-2,4-cyclooctadien-1-yl)Ru(r|6-phtalide)][BF4]:

[0119] It was obtained according to the above-described general procedure as a beige yellow solid in 98% yield.

[0120] 1H NMR (500 MHz, CD2CI2): 86.87 (d, J = 6.0 Hz, 1 H, CH Ar), 6.82 (d, J = 6.0 Hz, 1 H, CH Ar), 6.72 (t, J = 6.8 Hz, 1 H, =CH), 6.49 (t, J = 6.0 Hz, 1 H, CH Ar), 6.39 (t, J = 6.0 Hz, 1 H, CH Ar), 5.50 (d, J = 16.0 Hz, 1 H, CH2), 5.40 (d, J = 16.0 Hz, 1 H, CH2), 4.98 (ddd, J = 9.2, 6.8, 1 .6 Hz, 1 H, =CH), 4.86 (ddd, J = 9.2, 6.8, 1 .6 Hz, 1 H, =CH), 4.46 (dt, J = 9.2, 3.6 Hz, 1 H, =CH), 4.30 (dt, J = 9.2, 3.6 Hz, 1 H, =CH), 1 .97 (dm, J = 17.2 Hz, 2H, 2 CH2), 1.42 (ddq, J = 17.2, 13.6, 3.2 Hz, 2H, 2 CH2), 1.30 (dm, J = 13.6 Hz, 1 H, CH2), 0.07 (qt, J = 13.6, 2.4 Hz, 1 H, CH2).

[0121] 13C NMR (126 MHz, CD2CI2): 8 168.0 (CO), 115.0 (C Ar), 108.5 (=CH), 94.3 (CH Ar), 94.0 (CH Ar), 89.4 (CH Ar), 88.5 (CH Ar), 87.5 (C Ar), 85.9 (=CH), 84.7 (=CH), 69.2 (CH2), 64.3 (=CH), 63.0 (=CH), 28.3 (CH2), 28.1 (CH2), 18.9 (CH2).

[0122] [(q5-2,4-cyclooctadien-1-yl)Ru(q6-chlorobenzene)][BF4]:

[0123] It was obtained according to the above-described general procedure as a beige yellow solid in 95% yield.

[0124] 1H NMR (500 MHz, CD2CI2): 86.68 (t, J = 6.8 Hz, 1 H, =CH), 6.52 (d, J = 6.0 Hz, 2H, 2 CH Ar), 6.43 (t, J = 6.0 Hz, 2H, 2 CH Ar), 6.12 (t, J = 6.0 Hz, 1 H, CH Ar), 4.89 (ddd, J = 9.2, 6.8, 1.6 Hz, 2H, 2 =CH), 4.42 (dt, J = 9.2, 3.6 Hz, 2H, 2 =CH), 2.01 (dm, J = 16.8 Hz, 2H, 2 CH2), 1.52 (ddt, J = 17.6, 13.8, 3.2 Hz, 2H, 2 CH2), 1.33 (dm, J = 13.8 Hz, 1 H, CH2), 0.12 (qt, J = 13.8, 2.6 Hz, 1 H, CH2).

[0125] 13C NMR (126 MHz, CD2CI2): 8 110.8 (C Ar), 108.2 (=CH), 94.1 (2 CH Ar), 93.9 (2 CH Ar), 92.0 (CH Ar), 84.4 (2 =CH), 62.6 (2 =CH), 28.6 (2 CH2), 19.1 (CH2).

[0126] [(r|5-2,4-cyclooctadien-1-yl)Ru(r|6-benzaldehyde)][BF4]:

[0127] It was obtained according to the above-described general procedure as a beige yellow solid in 92% yield.

[0128] 1H NMR (500 MHz, CD2CI2): 8 10.09 (s, 1 H, CHO), 6.81 (d, J = 6.2 Hz, 2H, 2 CH Ar), 6.73 (t, J = 6.8 Hz, 1 H, =CH), 6.49 (t, J = 6.2 Hz, 1 H, CH Ar), 6.38 (t, J = 6.2 Hz, 2H, 2 CH Ar), 4.97 (ddd, J = 9.0, 6.8, 1.4 Hz, 2H, 2 =CH), 4.52 (dt, J = 9.0, 3.6 Hz, 2H, 2 =CH), 1.99 (dm, J = 17.2 Hz, 2H, 2 CH2), 1.41 (ddt, J = 17.2, 13.8, 3.2 Hz, 2H, 2 CH2), 1.29 (dm, J = 13.8 Hz, 1 H, CH2), 0.10 (qt, J = 13.8, 2.6 Hz, 1 H, CH2).13C NMR (126 MHz, CD2CI2): 8 190.0 (CO), 108.5 (=CH), 95.7 (C Ar), 94.9 (CH Ar), 94.2 (4 CH Ar), 84.4 (2 =CH), 61.3 (2 =CH), 28.7 (2 CH2), 18.9 (CH2).

[0129] [(iq5-2,4-cyclooctadien-1-yl)Ru(iq6-acetophenone)][BF4]:

[0130] It was obtained according to the above-described general procedure as a beige yellow solid in 96% yield.

[0131] 1H NMR (500 MHz, CD2CI2): 86.85 (d, J = 6.2 Hz, 2H, 2 CH Ar), 6.69 (t, J = 6.8 Hz, 1 H, =CH), 6.49 (t, J = 6.2 Hz, 1 H, CH Ar), 6.32 (t, J = 6.2 Hz, 2H, 2 CH Ar), 4.90 (ddd, J = 9.0, 6.8, 1.6 Hz, 2H, 2 =CH), 4.44 (dt, J = 9.0, 3.6 Hz, 2H, 2 =CH), 2.67 (s, 3H, CH3), 1.96 (dm, J = 16.8 Hz, 2H, 2 CH2), 1.36 (ddt, J = 1.8, 13.6, 3.2 Hz, 2H, 2 CH2), 1.28 (dm, J = 13.6 Hz, 1 H, CH2), 0.10 (qt, J = 13.6, 2.6 Hz, 1 H, CH2).

[0132] 13C NMR (126 MHz, CD2CI2): 8 195.9 (CO), 108.3 (=CH), 97.1 (C Ar), 94.6 (CH Ar), 93.9 (2 CH Ar) , 93.8 (2 CH Ar), 84.1 (2 =CH), 60.8 (2 =CH), 28.2 (2 CH2), 27.0 (CH3), 18.9 (CH2).

[0133] The disclosed subject matter has been described with reference to specific details of particular embodiments thereof. It is not intended that such details be regarded as limitations upon the scope of the disclosed subject matter except insofar as and to the extent that they are included in the accompanying claims.

[0134] Therefore, the exemplary embodiments described herein are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the exemplary embodiments described herein may be modified and practiced in different but equivalent manners apparent to those of ordinary skill in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope and spirit of the exemplary embodiments described herein. The exemplary embodiments described herein illustratively disclosed herein suitably may be practiced in the absence of any element that is not specifically disclosed herein and / or any optional element disclosed herein.

Claims

WHAT IS CLAIMED IS:1 . A process for the isomerization of a compound having at least one double bond, the process comprising reacting the compound having at least one double bond with a compound of formula (I),[(L1)Ru(L2)][X] (I), whereinL1represents a dienyl ligand;L2represents an arene, with the proviso that the arene is not benzene or toluene;X represents CIO4; R3SC>3', wherein R3is Cl, F, Ci-Cs fluoroalkyl or fluoroaryl group; PFe’, SbCle', AsCle', SbFe', AsFe', B(R4)4', wherein R4is F or an aryl group; thereby forming the corresponding isomerized compound.

2. The process according to claim 1 , wherein the arene is selected from the group consisting of benzene derivative, naphthalene, anthracene, phenanthrene, biphenyl, and derivatives thereof, with the proviso that the arene is not toluene.

3. The process according to claim 1 or 2, wherein the arene is represented by formula (II)wherein R5, R6, and R7are each, independently, H, a linear or branched Ci-Ce alkyl group, halogen, CN, C(O)R8, C(O)OR9, or OR10,wherein R8, R9, and R10are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, or a heteroatom-based covalent group, typically difluoroboranyl group (BF2); or by formula (III)wherein X’ and X” are each, independently, CR11R12, C(O), O, NR13, S, S(O), or S(O)2, wherein R11, R12, and R13are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, and wherein n is 1 or 2, with the proviso that the arene is not benzene or toluene.

4. The process according to any one of claims 1 to 3, wherein the arene is represented by formula (II)wherein R5, R6, and R7are each, independently, a linear or branched Ci-Ce alkyl group or OR10, wherein R10is a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group; or wherein R5and R6are each H, and R7is a linear or branched Ci-Ce alkyl group, C(O)R8, or C(O)OR9, wherein R8and R9are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, or a heteroatom-based covalent group, typically difluoroboranyl group (BF2), with the proviso that the arene is not toluene.

5. The process according to claim 4, wherein R5, R6, and R7are each, independently, methyl or methoxy; or wherein R5and R6are each H and R7is C(O)R8, or C(O)OR9, wherein R8and R9are each, independently, H, methyl or ethyl group, or a difluoroboranyl group (BF2).

6. The process according to any one of claims 1 to 3, wherein the arene is represented by formula (III)wherein X’ is C(0) and X” is O.

7. The process according to any one of claims 1 to 6, L1is an eta-5 dienyl ligand, typically derived from a diene selected from the group consisting of 1 ,3- cyclooctadiene, 1 ,5-cyclooctadiene (COD), 2,4-dimethylpenta-2,4-diene, 2,3,4- trimethylpenta-1 ,3-diene, 2,4-dimethyl-1-oxa-2,4-pentadiene, 2,4-cycloheptadiene, and 1 ,4-heptadiene.

8. The process according to any one of claims 1 to 7, wherein the compound of formula (I) is present in a catalytic amount.

9. The process according to any one of claims 1 to 8, wherein the compound having at least one double bond is a compound of formula (IV),wherein p is 0 to 12, typically 1 to 12;R14represents a hydrogen atom, linear or branched Ci-Ce alkyl, C2-C6 alkenyl group, Ci-Ce alkoxy group, Ci-Ce cycloalkyl, C2-C6 cycloalkenyl group, or aryl; A represents C=O or C(Ra)2, wherein Rais, at each occurrence, independently, a hydrogen atom or a linear or branched Ci-Ce alkyl group or a Ci-Ce alkoxy group;R15, R16, R17, and R18at each occurrence, represents, independently, hydrogen atom, linear or branched Ci-Ce alkyl, C2-C6 alkenyl group, Ci-Ce alkoxy group, Ci-Ce cycloalkyl, C2-C6 cycloalkenyl group, or aryl; or R16and R17together with the carbon atoms to which they are attached form a carbocyclic or heterocyclic ring; or, alternatively, R18and R15together with the carbon atoms to which they are attached form a carbocyclic or heterocyclic ring; or, alternatively, R17and R14together with the carbon atoms to which they are attached form a carbocyclic or heterocyclic ring.

10. The process according to claim 9, wherein the compound of formula (IV) is a compound of formula (IVb)wherein A, R14to R18are as defined, and R19at each occurrence, represents, independently, hydrogen atom, linear or branched Ci-Ce alkyl, C2-C6 alkenyl group, Ci-Ce alkoxy group, Ci-Ce cycloalkyl, C2-C6 cycloalkenyl group, or aryl.11 . The process according to claim 10, wherein the corresponding isomerized compound comprises a compound of formula (V)wherein A, R14to R19are as defined.

12. A compound of formula (I),[(L1)Ru(L2)][X] (I), whereinL1represents a dienyl ligand;L2represents an arene;X represents CIO4; R3SC>3', wherein R3is Cl, F, Ci-Cs fluoroalkyl or fluoroaryl group; PFe’, SbCle', AsCle', SbFe', AsFe', B(R4)4', wherein R4is F or an aryl group; wherein the arene is selected from the group consisting of naphthalene, anthracene, phenanthrene, biphenyl, a compound represented by formula (II)wherein R5, R6, and R7are each, independently, H, a linear or branched Ci-Ce alkyl group, halogen, CN, C(O)R8, C(O)OR9, or OR10, wherein at least one of R5, R6, and R7is not H; wherein R8, R9, and R10are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, or a heteroatom-based covalent group, typically difluoroboranyl group (BF2), with the proviso that the arene is not toluene; and a compound represented by formula (III)wherein X’ and X” are each, independently, CR11R12, C(O), O, NR13, S, S(O), or S(O)2, wherein R11, R12, and R13are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, and wherein n is 1 or 2.

13. The compound according to claim 12, wherein the arene is represented by formula (II)wherein R5, R6, and R7are each, independently, a linear or branched Ci-Ce alkyl group or OR10, wherein R10is a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group; or wherein R5and R6are each H, and R7is a linear or branched Ci-Ce alkyl group, C(O)R8, or C(O)OR9,wherein R8and R9are each, independently, H, or a linear or branched Ci-Ce alkyl group, typically methyl or ethyl group, or a heteroatom-based covalent group, typically difluoroboranyl group (BF2), with the proviso that the arene is not toluene.

14. The compound according to claim 13, wherein R5, R6, and R7are each, independently, methyl or methoxy; or wherein R5and R6are each H and R7is C(O)R8, or C(O)OR9, wherein R8and R9are each, independently, H, methyl or ethyl group, or a difluoroboranyl group (BF2).

15. The compound according to claim 12, wherein the arene is represented by formula (III)wherein X’ is C(0) and X” is O.

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