Photodehydrogenation of aldehydes or ketones to yield alpha-beta olefinically unsaturated aldehydes or ketones

Abstract

The present invention relates to a process of photoredox catalysed dehydrogenation of an aldehyde or a ketone (AK) to an alpha-beta olefinically unsaturated aldehyde or ketone (UAK) in the presence of: - at least one cobalt complex (CC); - at least one photocatalyst (PC) being an organic photocatalyst, preferably a cyanoarene polyaromatic photocatalyst, or an iridium complex; - at least one amine (A) or an ammonium salt (ASA) of the at least one amine (A) and an organic or inorganic acid; - light. It has been shown that by said process an alpha-beta olefinically unsaturated aldehyde or ketone (UAK) can be obtained at high conversion in high yields and selectivity.

Description

[0001] PHOTODEHYDROGENATION OF ALDEHYDES OR KETONES TO YIELD ALPHA-BETA OLEFINICALLY UNSATURATED ALDEHYDES OR KETONES

[0002] Technical Field

[0003] The present invention relates to the field of dehydrogenation of aldehydes or ketones and the field of synthesis of alpha-beta olefinical ly unsaturated aldehydes or ketones.

[0004] Background of the invention

[0005] Alpha-beta olefinically unsaturated aldehydes or ketones are important intermediates in the field of flavours and fragrances.

[0006] Zhou M.-J. et al., J. Am. Chem. Soc. 2021, 143, 16470-164895 discloses a photodehydrogenation of aliphatics to alkenes using organophotoredox cobalt dual catalysis. However, this method is rather limited. For example, as example P71 on page 16473 shows, cyclohexanone is not photodehydrogenated to cyclohex-2 -en-1 -one.

[0007] Zhao H. et al., Angew. Chem, Int. Ed. 2022, 61, e202201870 discloses formation of aromatic aldehydes from cyclohexyl aldehydes by use of photoredox catalysts and cobalt complexes. The formation of alpha-beta olefinically unsaturated aldehydes or ketones is neither disclosed nor suggested.

[0008] Summary of the invention

[0009] Therefore, the problem to be solved by the present invention is to offer a method for the formation of alpha-beta olefinically unsaturated aldehydes or ketones from aldehydes or ketones, particularly also for cycloaliphatic ketones such as cyclohexanone.

[0010] Surprisingly, it has been found that the process according to claim 1 offers a solution to this problem.

[0011] It has been surprisingly found that by this method alpha-beta olefinically unsaturated aldehydes or ketones can be formed in high yields and selectivity. It has been found that this method is particularly suitable for the synthesis of alphabeta olefinically unsaturated aldehydes.

[0012] Further aspects of the invention are subject of further independent claims. Particularly preferred embodiments are subject of dependent claims.Detailed description of the invention

[0013] In a first aspect the present invention relates to a process of producing an alpha-beta olefinically unsaturated aldehyde or ketone (UAK) by photodehydrogenation of an aldehyde or a ketone (AK) in the presence of

[0014] - at least one cobalt complex (CC);

[0015] - at least a photocatalyst (PC) being an organic photocatalyst, preferably a cyanoarene polyaromatic photocatalyst, or an iridium complex;

[0016] - at least one amine (A) or an ammonium salt (ASA) of the at least one amine (A) and an organic or inorganic acid;

[0017] - light.

[0018] In an embodiment, the at least one amine (A) or an ammonium salt (ASA) of the at least one amine (A) and an organic or inorganic acid is an ammonium salt (ASA) of the at least one amine (A) and an organic or inorganic acid.

[0019] In an embodiment, there is provided a process of producing an alpha-beta olefinically unsaturated aldehyde or ketone (UAK) by photodehydrogenation of an aldehyde or a ketone (AK) in the presence of

[0020] at least one cobalt complex (CC);

[0021] at least a photocatalyst (PC) being an organic photocatalyst, preferably a cyanoarene polyaromatic photocatalyst, or an iridium complex;

[0022] an ammonium salt (ASA) of at least one amine (A) and an organic or inorganic acid;

[0023] light.

[0024] In an embodiment, the aldehyde or the ketone (AK) is an aldehyde.

[0025] In a preferred embodiment, the alpha-beta olefinically unsaturated aldehyde or ketone (UAK) is an alpha-beta olefinically unsaturated aldehyde.

[0026] In an embodiment, there is provided a process of producing an alpha-beta olefinically unsaturated aldehyde by photodehydrogenation of an aldehyde in the presence ofat least one cobalt complex (CC);

[0027] at least a photocatalyst (PC) being an organic photocatalyst, preferably a cyanoarene polyaromatic photocatalyst, or an iridium complex;

[0028] an ammonium salt (ASA) of at least one amine (A) and an organic or inorganic acid;

[0029] light.

[0030] For sake of clarity, some terms used in the present document are defined as follows:

[0031] In the present document, a “Cx-y-alkyl” group is an alkyl group comprising x to y carbon atoms, i.e., for example, a Ci-3-alkyl group is an alkyl group comprising 1 to 3 carbon atoms. The alkyl group can be linear or branched. For example -CH(CH3)-CH2-CH3 is considered as a C4-alkyl group.

[0032] A “Cx-y-alkylene” group is an alkylene group comprising x to y carbon atoms. An alkylene is a substituent which, formally, is obtained from an alkane by removal of 2 H atoms and forms a carbon-carbon bond with each of the two rests of the molecule the alkylene group is bound to. For example, a Ci-3-alkylene group is an alkylene group comprising 1 to 3 carbon atoms. The alkylene group can be linear or branched. For example,

[0033] -CH2-CH2-CH2- and -CH(CH3)-CH2- and -C(CH2-CH3)- and -C(CH3)2- are all considered as a Cs-alkylene group.

[0034] In the present document, “aralkyl” group is an alkyl group of which at least one H is substituted by an aryl group. Hence, for example, benzyl (= C6H5-CH2-) is a Cyaralkyl group.

[0035] In case identical labels for symbols or groups are present in several formulae, in the present document, the definition of said group or symbol made in the context of one specific formula applies also to other formulae which comprises the same said label.

[0036] The term “independently from each other” in this document means, in the context of substituents, moieties, or groups, that identically designated substituents, moieties, or groups can occur simultaneously with a different meaning in the same molecule.-4 - 2024P00183WC Any single dotted line in any formulae represents the bond by which said substituent is bound to the rest of a molecule.

[0037] The term “olefinically unsaturated" means in this document that an olefinic unsaturation (C=C) is present. This is used to contrast to unsaturations which are present in alkynes (C-C triple bonds) or double bonds of carbon atoms to hetero atoms such as C=O, or C=N or aromatic C-C bonds.

[0038] Ts" means in the present document tosylate, i.e. a substitiuent of the formula / “\

[0039] — SO2>

[0040]

[0041] Aldehyde or ketone (AK)

[0042] The aldehyde or ketone (AK) is not an alpha-beta olefinically unsaturated aldehyde or ketone or a gamma-delta olefinically unsaturated aldehyde or ketone.

[0043] It is preferred that the aldehyde or a ketone (AK) and, accordingly, the alpha-beta olefinically unsaturated aldehyde or ketone (UAK) are aldehydes.

[0044] Preferably, the aldehyde or ketone (AK) is a compound of the formula (I) and the alpha-beta olefinically unsaturated aldehyde or ketone (UAK) is of the formula (II)

[0045] w

[0046]

[0047] herein W represents 0, S, NR, or R3R3; andR\ / / \R4

[0048] / \

[0049] W represents 0

[0050]

[0051] , S, NR, or > '»

[0052] wherein R represents a Ci- -alkyl group or Ce-12-aryl group or C6-12- aralkyl group o

[0053]

[0054] r a "__so2Ar

[0055] with Ar being a Ce-12-aryl group, preferably a p-tolyl group;

[0056] with the proviso, that either W or W, are different from 0, S, or NR;

[0057] X represents

[0058] either

[0059] H or a Ci-10-alkyl group or a C6-i2-cycloalkyl group or a Ce-12-aryl group;

[0060] or

[0061] forms together with at least one substituent of the group consisting of R1, R2, R3, R3, R4, R4, R5, R5, R6, R6, R7, R7and R8an alkylene group yielding a 5- to 12-membered ring; and

[0062] R1, R2, R3, R3, R4, R4, R5, R5, R6, R6, R7, R7'and R8, independently from each other,

[0063] either,

[0064] represent H, a Ci-10-alkyl group or a Ce-12-aryl group; particularly H or CH3;

[0065] or

[0066] form together with X or with at least one other substituent of the group consisting of R1, R2, R3, R3, R4, R4, R5, R5, R6, R6, R7, R7' and R8an alkylene group yielding a 5- to 12-membered ring, n1, n2 and n3, independently from each other, represent each a value of 0 or 1 or 2 or 3;

[0067] and wherein any wavy line represents a carbon-carbon bond which when linked to the carbon-carbon double bond is either in the Z- or in the E-configuration.In one of the embodiments, the substituents R1, R2, R3, R3', R4, R4', R5, R5', R6, R6', R7, R7'and R8independently from each other, represents H, a C1-10-alkyl group or a Ce-12-aryl group; particularly H or CH3.

[0068] In this embodiment, the aldehyde or ketone (AK) of the formula (I) is a linear or branched aldehyde or ketone.

[0069] In another embodiment, at least two substituents of the group consisting of R1, R2, R3, R4, R4', R5, R5', R6, R6', R7, R7'and R8, form together an alkylene group yielding a 5- to 12-membered ring.

[0070] In this embodiment, the aldehyde or ketone (AK) of the formula (I) has at least one cyclic structure of ring size 5 to 12.

[0071] A particular aldehyde or ketone of this embodiment is an aldehyde or ketone of the formula ( l-Cy-l)

[0072]

[0073] It is preferred that the group of the formula

[0074]

[0075] '' X of the aldehyde or a ketone (AK) of the formula (I) is directly linked to a C5-2o-cycloalkyl group.

[0076] Preferably the aldehyde or ketone of the formula ( l-Cy-l) is selected from the group consisting of compounds of the formula (l-Cy-la), (l-Cy-lb), ( l-Cy-lc), (l-Cy-ld) and (l-Cy-le)(I-Cy-Ib),

[0077] (l-Cy-ld) and

[0078] (l-Cy-le).

[0079]

[0080] Particularly, the aldehyde or a ketone (AK) is a compound of the formula (l-A) and the alpha-beta olefinically unsaturated aldehyde or ketone (UAK) is of the formula (I l-A)

[0081]

[0082] In a particular embodiment, the aldehyde or a ketone (AK) is a compound of the formula (l-AA), preferably of the formula (l-AAS) and the alpha-beta olefinically unsaturated aldehyde or ketone (UAK) is a compound of the formula ( I l-AA), preferably of the formula (ll-AAS)

[0083]

[0084]

[0085] In another embodiment, X forms together with at least one substituent of the group consisting of R1, R2, R3, R3', R4, R4', R5, R5', R6, R6', R7, R7'and R8an alkylene group yielding a 5- to 12-membered ring.

[0086] In this embodiment, the aldehyde or ketone (AK) of the formula (I) is a cyclic ketone having at least one cyclic structure of ring size 5 to 12.

[0087] A particular aldehyde or ketone of this embodiment is an aldehyde or ketone of the formula (l-Cy-ll)

[0088] (I-Cy-Il)

[0089]

[0090] Preferably the aldehyde or ketone of the formula (l-Cy-ll) is selected from the group consisting of compounds of the formula (l-Cy-lla), (l-Cy-llb), (l-Cy-llc), (l-Cy-lld), (l-Cy-lle), (l-Cy-llf) and (l-Cy-llg)

[0091] (l-Cy-llb),

[0092] (l-Cy-lld),

[0093] (l-Cy-lle), (l-Cy-llf) and N

[0094]

[0095] Ts.0

[0096] < > (l-Cy-llg).

[0097]

[0098] It is preferred, that R2Is different from H.

[0099] It is, furthermore, preferred, that the aldehyde or a ketone (AK) and the alpha-beta olefinically unsaturated aldehyde or ketone (UAK \) is a

[0100] \ \ \ \ / / / / / n aldehyde.

[0101] In one of the embodiments, both W and W represent R3A R3.

[0102] It is preferred that, X is H or a Ci -1 o-alkyl group or a C6-i2-cycloalkyl group.

[0103] It is, furthermore, preferred that R2represents H or a Ci -1 o-alkyl group.

[0104] Cobalt complex

[0105] The process of the present invention is performed in the presence of at least one cobalt complex (CC).

[0106] The cobalt complex is a complex of Co(ll) or Co(lll). It is preferred that preferably that the cobalt complex at least one organic ligand, preferably a chelating ligand, particularly ligands having the structural element of C=N, more preferably an oxime, which is bound via nitrogen atom to the cobalt.

[0107] It is particularly preferred that the cobalt complex is a complex of Co(lll).

[0108] It is particularly preferred that the cobalt complex (CC) is a cobalt complex selected from the group consisting of the cobalt complexes of the formula (CC1 ), (CC2), (CC3), (CC4), (CC5), (CC5), (CC6), (CC7), (CC8), (CC9), (CC10), (CC11), (CC12), (CC13), (CC14), and (CC15)

[0109] OH OH

[0110]

[0111] (CC1) (CC2)(CC4)

[0112] (CC7)

[0113] (CC10) (CC12)

[0114]

[0115] (CC15)

[0116] It is particularly preferred that the cobalt complex (CC) is a cobalt complex selected from the group consisting of the cobalt complexes of the formula (CC1 ),(CC2), (CC3), (CC4), (CC5), (CC5), (CC6), (CC7), (CC8), (CC9), (CC10), (CC11), (CC12), (CC13), and (CC14)

[0117] I I OH O’

[0118] (CC9)

[0119]

[0120] (CC10) (CC12)

[0121]

[0122] (CC14).

[0123] Photocatalyst

[0124] The process of the present invention is performed in the presence of at least one photocatalyst (PC), which is either an organic photocatalyst or an iridium complex.

[0125] In one embodiment, the photocatalyst (PC) is an iridium complex.

[0126] It is preferred that the photocatalyst (PC) is an iridium complex which comprises at least a ligand from the group consisting of

[0127] Y2

[0128] and

[0129]

[0130] * *

[0131] and

[0132] wherein

[0133] Y1, Y1', Y2, Y2', Y3and Y3', independently from each other, represents H, a Ci -4-alkyl group or a halogenated Ci -4-alkyl group or a halide or a C1-4 alkoxy group;

[0134] and wherein * marks the atom of the ligand which is bound to the iridium center.It is particularly preferred that the iridium complex is an iridium complex which is selected from the group consisting of the compounds of the formula (PC1), (PC2), (PC3), (PC4), (PC5), (PC6), (PC7) and (PC8)

[0135] (PC1)

[0136] (PC3)

[0137] (PC5)

[0138] (PC7)

[0139]

[0140] In another embodiment, the photocatalyst (PC) is an organic

[0141] photocatalyst.There exist a broad variety of organic photocatalysts as disclosed by Romero N. A. et al. in Chem. Rev. 2016, 116, 10075-10166, which is here with incorporated by reference. The organic photocatalyst is particularly selected from the group consisting of cyanoarenes, benzophenones, quinones, pyryliums, thiapyryliums, quinoliniums, acridiniums, xanthene dyes, rhodamines, phenothiazines and polyaromatic photocatalysts.

[0142] It is preferred that the organic photocatalyst is a cyanoarene polyaromatic photocatalyst which is a compound of the formula (PCO)

[0143] (PCO)

[0144]

[0145] wherein A1, A2, A3, A4and A5, independently from each other, represents either a halide, CN or an aromatic secondary amino group, particularly of the formula (B1), particularly of the formula (B2)

[0146] (B1) (B2)

[0147]

[0148] Z' wherein Ar1and Ar2represent either a phenyl or a substituted phenyl groups or form together a bridged di-phenylic group;

[0149] Z1and Z2, independently from each other, represents represent either H, a halide or a Ci-4-alkyl group or a Ci-4-alkoxy group;

[0150] and any dotted single line in any formulae represents the bond by which said substituent is bound to the rest of a molecule;

[0151] with the proviso, that

[0152] at least one of the substituents A1, A2, A3, A4and A5is an aromatic secondary amino group;and not more than two of the substituents A1, A2, A3, A4and A5are halides.

[0153] It is particularly preferred that this cyanoarene polyaromatic photocatalyst is a cyanoarene polyaromatic photocatalyst, which is selected from the group consisting of the compounds of the formula (PC9), (PC10), (PC11), (PC12), (PC13), (PC14), (PC15), (PC16) and (PC17)

[0154]

[0155]

[0156] It is preferred that the photocatalyst (PC) is an iridium complex.

[0157] Amine (A) or ammoniums salt (ASA) of amine (A) and organic or inorganic acid The process of the present invention is performed in the presence of at least one amine (A) or an ammonium salt (ASA) of the at least one amine (SA) and an organic or inorganic acid.

[0158] According to the invention, the at least one amine (A) or an ammonium salt (ASA) of the at least one amine (SA) and an organic or inorganic acid is different from the at least one photocatalyst (PC).

[0159] It is preferred that the at least one amine (A) is a primary amine or a secondary amine. It may be linear, branched or cyclic. The at least one amine (A) preferably a secondary amine. Preferred amines (A) are secondary, cyclic amines.

[0160] Preferable the at least one amine (A) is a secondary amine selected from the group consisting of the formula (Ai) or (Aii)

[0161]

[0162] wherein

[0163] Q represents CH2or CH2CH2or O or S or NQ3;

[0164] Q1, Q1', Q2and Q2', independently from each other, represents H, or a C1-4- alkyl group or a carboxyl group;

[0165] Q3represents H or a Ci-4-alkyl group, preferably a methyl group;

[0166] more preferably a secondary amine selected from the group consisting of pyrrolidine, piperidine, piperazine, methyl piperazine, morpholine, thiomorpholine and proline.

[0167] The at least one amine (A) or an ammonium salt (ASA) of the at least one amine (SA) and an organic or inorganic acid is preferably an ammonium salt of said secondary amine (Ai) or (Aii) and an organic or inorganic acid.

[0168] The organic or inorganic acid suitable for the formation of an ammonium salt (ASA) of the at least one amine is preferably a carboxylic acid or a sulfonic acid, particularly an aromatic sulfonic acid.

[0169] In one of the embodiments, said organic or inorganic acid is preferably a carboxylic acid having 1 to 6 carbon atoms, particularly acetic acid or trifluoroacetic acid or trichloroacetic acid.

[0170] In another embodiment, said organic or inorganic acid is preferably a sulfonic acid, particularly an aromatic sulfonic acid, or a halogenated alkylsulfonic acid. Preferably said sulfonic acid is trifluoromethanesulfonic acid (= triflic acid) or p-toluenesulfonic acid (=pTSA).

[0171] It is preferred that ammonium salt (ASA) of the at least one amine and an organic or inorganic acid, is an ammonium salt of the at least one amine and an organic acid.It is particularly preferred that the amine (A) or an ammonium salt (ASA) of the at least one amine (A) and an organic or inorganic acid is an ammonium salt (ASA) of an amine (SA) and an organic or inorganic acid.

[0172] Particularly preferred as ammonium salt (ASA) of an amine is an ammonium salt (ASA) of morpholine or methyl piperazine and an organic or inorganic acid. Even more preferred is an ammonium salt (ASA) of an amine which is selected from the group consisting of the compounds of the formula (ASA1), (ASA2), (ASA3), (ASA4), (ASA5), and (ASA6).

[0173] (ASA2)

[0174] (ASA3)

[0175] (ASA5) (ASA6)

[0176]

[0177] In a preferred embodiment, the ammonium salt (ASA) of the at least one amine (A) is an ammonium salt (ASA) of formula (ASA6).

[0178] It has been found that additionally to the at least one amine (A) or an ammonium salt (ASA) of the at least one amine (A) and an organic or inorganic acid, the presence of a tertiary amine, particularly cyclic tertiary amine, preferably 1,4-Diazabicyclo[2.2.2]octan (=DABCO), is advantageous for the dehydrogenation reaction. It has been found that both conversion and yield could be increased if such tertiary amine is added.

[0179] Light

[0180] The process of the present invention is performed in the presence of light. Different light sources for the light can be chosen by the person skilled in the art. Particularly Xe high pressure arc lamps, mercury vapor lamps, laser or LED lamps can be used as suitable light sources. These lamps can provide light with different wavelengths form ultraviolet to infrared light.It is preferred that the light used for the process is a light of the wavelengths of between 300 and 500 nm, preferably between 365 and 460 nm, particularly between 400 and 460 nm.

[0181] In a preferred embodiment, the light used for the process is a light of the wavelengths of between 300 and 500 nm, preferably between 365 and 460 nm, more preferably between 380 and 460 nm, particularly between 390 and 460 nm. In a particular embodiment, the light used for the process is a light of the wavelength of between 400 and 460 nm.

[0182] In one embodiment, the light which is used can be realized by filtering the undesired light wavelengths from a light source. For example, a light source having a multichromatic or white emission can be filtered by a filter which blocks off the undesired wavelength.

[0183] There are different possibilities of such filters known and commercially available such as absorption, dichroic, monochromatic, band-pass, short-pass or wedge filters, using different physical methods for filtration of light.

[0184] In another embodiment, a light source is chosen which has the emission in the range of the desired range of wavelength. In a very specific embodiment, the light sources emit monochromatic or quasi-monochromatic light of the desired wavelength. Such light sources can be chosen by the person skilled in the art.

[0185] Particularly preferred are LED lamps, particularly LED lamps emitting a light of 420 nm.

[0186] There exist different possibilities how the light source is arranged to allow the emitted light to the reaction mixture.

[0187] Suitable arrangements are known as photoreactors to the person skilled in the art.

[0188] In one of the embodiments, the light source is inserted in the reaction vessel. In another embodiment the light source is arranged in or outside the wall of the reactor, in which case the walls need to be transparent to light of the desired wavelength.

[0189] In an even further embodiment, the reaction medium is in contact with light source in form of a thin film.It also can be advantageous to use helical arrangements of light sources or reaction vessel, respectively, to optimize optimal photo absorption.

[0190] Solvents might be used for the process of the invention. It is obvious that for the choice of solvent it is advantageous that said solvent does not absorb or does not absorb much of the light of the desired wavelength to assure to avoid the reaction to occur quantitatively.

[0191] The use of a solvent is advantageous to adjust the concentration of the ingredients allowing an optimal absorption of the light by the absorbing species in the reaction mixture assuring optimal conversion and yield.

[0192] It is preferred that the solvent is selected from the group consisting of alcohols, aliphatic ketones, alkylnitriles, ethers, halogenated hydrocarbons and dialkylsulfoxydes.

[0193] Particularly suitable are organic solvents selected from the group consisting of methanol, ethanol, acetonitrile, acetone, a,a,a-trifluorotoluene, 1,2-dichloroethane and dimethylsulfoxyde, in particular acetonitrile.

[0194] It is preferred that the unsaturated aldehyde or ketone of the formula (I) is present in the range 0.05 - 2 mol / Liter, preferably in the range of 0.1 – 1 mol / Liter, in respect to the reaction mixture.

[0195] It is further preferred that the cobalt complex (CC) is present in the reaction mixture in an amount that the molar ratio of cobalt complex (CC) I compound of the formula (I) is in the range of 0.1 to 5 mol% preferably in the range of 0.25 to 1 mol%.

[0196] It is further preferred that the photocatalyst (PC) is present in the reaction mixture in an amount that the molar ratio of photocatalyst (PC) I compound of the formula (I) is in the range of 0.1 to 5 mol%, preferably in the range of 0.25 to 1 mol%.

[0197] It is further preferred that the amine (A) or an ammonium salt (ASA) of the at least one amine (A) and an organic or inorganic acid is present in the reaction mixture in an amount that the molar ratio of amine (A) or an ammonium salt (ASA) / compound of the formula (I) is in the range of 5 – 20 mol%, preferably in the range of 10 - 15 mol%.

[0198] The process can be performed at a temperature of preferably between 0°C and 60°C, particularly between 10°C and 40°C, most preferably between 20 and 30°C.

[0199] It is preferred that the process is performed in inert atmosphere, particularly under nitrogen or argon.

[0200] Alpha-beta olefinically unsaturated aldehyde or ketone (UAK)

[0201] The process leads to an alpha-beta olefinically unsaturated aldehyde or ketone (UAK).

[0202] The process leads particularly to an alpha-beta olefinically unsaturated aldehyde or ketone (UAK) of the formula (II).

[0203]

[0204] The residues are the same as in the corresponding aldehyde or ketone (AK) of the formula (I).

[0205] In one of the preferred embodiments, the aldehyde or ketone (AK) of the formula (I) is of formula ( l-Cy-l) which leads to the formation of the alpha-beta olefinically unsaturated aldehyde or ketone (UAK) of the formula (ll-Cy-l)

[0206] (Il-Cy-I).

[0207]

[0208] Preferably the alpha-beta olefinically unsaturated aldehyde or ketone (UAK) of the formula (ll-Cy-l) is is selected from the group consisting of compounds of the formula ( I l-Cy-la), (ll-Cy-lb), (I l-Cy-lc), ( I l-Cy-ld) and (ll-Cy-le)

[0209] (ll-Cy-lb),

[0210] (I l-Cy-ld) and

[0211] (ll-Cy-le).

[0212]

[0213] In another preferred embodiment, the aldehyde or ketone (AK) of the formula (I) is of formula (l-Cy-ll) which leads to the formation of the alpha-beta olefinically unsaturated aldehyde or ketone (UAK) of the formula (ll-Cy-ll)

[0214] (ll-Cy-ll)

[0215]

[0216] Preferably the alpha-beta olefinically unsaturated aldehyde or ketone (UAK) of the formula (ll-Cy-ll) is is selected from the group consisting of compounds of the formula (ll-Cy-lla), (ll-Cy-llb), (ll-Cy-llc), (ll-Cy-lld), (ll-Cy-lle), (ll-Cy-llf) and (ll-Cy-llg)(ll-Cy-lla), (Il-Cy-Ilb),

[0217]

[0218] (ll-Cy-llc), (ll-Cy-lld),

[0219]

[0220] (ll-Cy-lle), (ll-Cy-llf) and

[0221]

[0222] (ll-Cy-llg).

[0223]

[0224] As shown above the combination of cobalt complex (CC); photocatalyst (PC), amine (A) or an ammonium salt (ASA) and aldehyde or ketone (AK) can advantageously yield by the above process in the presence of light the alpha-beta olefinically unsaturated aldehyde or ketone.

[0225] Hence, the present invention relates in a further aspect to a composition for comprising at least

[0226] a) a cobalt complex (CC);

[0227] b) a photocatalyst (PC) being an organic photocatalyst, particularly a cyanoarene polyaromatic photocatalyst, or an iridium complex; and c) an amine (A) or an ammonium salt (ASA) of the amine (A) and an organic or inorganic acid;

[0228] d) an aldehyde or a ketone (AK).

[0229] Details for these ingredients, such as their preferred embodiments and concentrations, ratios are described above in great details.

[0230] As shown above the combination of cobalt complex (CC); photocatalyst (PC) and amine (A) or an ammonium salt (ASA) can be used for the for the photodehydrogenation of an aldehyde or a ketone (AK).

[0231] Hence, the present invention relates in a further aspect to the use of a composition comprising at leasta) a cobalt complex (CC);

[0232] b) a photocatalyst (PC) being an organic photocatalyst, preferably a cyanoarene polyaromatic photocatalyst, or an iridium complex; and c) an amine (A) or an ammonium salt (ASA) of the amine (A) and an organic or inorganic acid;

[0233] for the photodehydrogenation of an aldehyde or a ketone (AK).

[0234] Details for these ingredients, such as their preferred embodiments and concentrations, ratios are described above in great details.

[0235] Examples

[0236] The following examples are provided to further illustrate the compositions and effects of the present invention. These examples are illustrative only and are not intended to limit the scope of the invention in any way.

[0237] General procedure of dehydrogenation

[0238]

[0239] A glass reactor (volume indicated in the respective tables) was charged under argon with (1S,2R,4S)-2,3,3,4-tetramethylcyclopentane-1-carbaldehyde (mmol as indicated in the respective tables) followed by photocatalyst (PC), as indicated in the respective tables, followed by the cobalt catalyst (CC), as indicated in the respective tables, followed by the amine (A) or the ammonium salt (ASA) of the amine, as indicated in the respective tables. The reaction mixture was irradiated at the wavelength, as indicated in the respective tables, under inert atmosphere at a temperature(7 / fr), as indicated in the respective tables. After a time (f / rr), as indicated in the respective tables), the irradiation was stopped, and the reaction mixture was analysed. The conversion and yield are reported in the respective tables.

[0240] Characterization of the product (colourless liquid) (S)-2, 3,3,4-tetramethylcyclopent- 1 -ene- 1 -carbaldehyde

[0241] 1H NMR (500 MHz, CD2CI2): 6 =9.9 (s, 1H), 2.60-2.56 (m, 1H), 2.0 (s, 1H), 1.98- 1.93 (m, 1 H), 1.89-1.83 (m, 1 H), 1.04 (s, 3H), 0.96 (s, 3H), 0.84 (s, 3H) ppm.2024P00183WC13C NMR (125 MHz, CD2CI2): 6 = 189.2 (CH), 169.7 (C), 136.4 (C), 50.9 (C), 42.8 (CH), 35.5 (CH2), 24.7 (CH3), 19.2 (CH3), 14.0 (CH3), 10.7 (CH3) ppm.- 26 - 2024P00183WC First series: Dehydrogenation using different photocatalysts (PC)

[0242] The dehydrogenation has been performed using the described general procedure conversion and yield are reported in table 1.

[0243] Example. PC1Conversion2[%] Yield2[%]

[0244] 1 (PC1) 45 34

[0245] 2 (PC2) 67 51

[0246] 3 (PC3) 42 29

[0247] 4 (PC4) 54 43

[0248] 5 (PC5) 56 44

[0249] 6 (PC6) 59 48

[0250] 7 (PC7) 26 14

[0251] 8 (PC8) 44 32

[0252] 9 (PC10) 42 27

[0253] 10 (PC11) 24 8

[0254] 11 (PC12) 38 23

[0255] 12 (PC13) 29 18

[0256] 13 (PC14) 58 42

[0257] 14 (PC15) 33 18

[0258] 15 (PC16) 25 9

[0259]

[0260] Table 1. Dehydrogenation of 4 mmol (1S,2R,4S)-2,3,3,4-tetramethylcyclopen- tane-1-carbaldehyde in 0.5 M acetonitrile using different photocatalysts, cobalt complex (CC) of the formula (CC1), and ammonium salt (ASA) of the formula (ASA6) with a molar ratio in ppm relative to the substrate of PC / CC / ASA = 2 500 / 2 500 / 100 000.

[0261] Volume reaction vessel: 10 ml; wavelength: 451 nm, tn- =23 h, 7 / ff=25°C.

[0262] 1PC: Photocatalyst of the formula

[0263] 2determined by GC, relative to (1S,2R,4S)-2,3,3,4-tetramethylcyclo- pentane-1 -carbaldehyde.

[0264] Second series: Dehydrogenation using different cobalt complexes (CC)

[0265] The dehydrogenation cyclisation has been performed using the described general procedure conversion and yield are reported in table 2.

[0266] Example. CC1Conversion2[%] Yield2[%]

[0267] 16 (CC1) 67 51

[0268]

[0269] - 27 - 2024P00183WC 17 (CC2) 67 31

[0270] 18 (CC3) 60 44

[0271] 19 (CC4) 62 44

[0272] 20 (CC5) 66 50

[0273] 21 (CC6) 50 31

[0274] 22 (CC7) 67 53

[0275] 23 (CC8) 66 52

[0276] 24 (CC9) 60 45

[0277] 25 (CC10) 60 47

[0278] 26 (CC11) 67 53

[0279] 27 (CC12) 62 47

[0280] 28 (CC13) 28 9

[0281] 29 (CC14) 67 50

[0282]

[0283] Table 2. Dehydrogenation of A mmol (1S,2R,4S)-2,3,3, A l-tetramethylcyclopen- tane-1-carbaldehyde in 0.5 M acetonitrile using different cobalt complexes (CC), photocatalyst (PC) of the formula (PC2), and ammonium salt (ASA) of the formula (ASA6) with a molar ratio in ppm relative to the substrate of PC / CC / ASA = 2500 / 2500 / 100000. Volume reaction vessel: 10 ml; wavelength: 451 nm, f / ff=23 h, 7 / ff=25°C.

[0284] 1CC: Cobalt complex of the formula

[0285] 2determined by GC, relative to (1S,2R,4S)-2,3,3,4-tetramethylcyclo- pentane-1 -carbaldehyde.

[0286] Third series: Dehydrogenation using different cobalt complexes (CC) and additional DABCO

[0287] The dehydrogenation has been performed using the described general procedure conversion and yield are reported in table 3.

[0288] Example. CC1DABCO Conversion2[%] Yield2[%] 30 (CC1) - 69 57

[0289] 31 (CC1) 1 eg380 65

[0290] 32 (CC7) - 69 60

[0291] 33 (CC7) 1 eg385 71

[0292] 34 (CC11) - 71 59

[0293] 35 (CC11) 1 eg377 60

[0294]

[0295] - 28 - 2024P00183WC Table 3. Dehydrogenation of 4 mmol (1S,2R,4S)-2,3,3,4-tetramethylcyclopen- tane-1-carbaldehyde in 0.5 M acetonitrile using different cobalt complexes (CC), photocatalyst (PC) of the formula (PC2), and ammonium salt (ASA) of the formula (ASA6) with a molar ratio in ppm relative to the substrate of PC / CC / ASA = 2 500 / 2 500 / 100 000. Volume reaction vessel: 10 ml; wavelength: 451 nm, f / ff=48 h, 7 / ff=25°C.

[0296] 1CC: Cobalt complex of the formula

[0297] 2determined by GC, relative to ((1S,2R,4S)-2,3,3,4-tetramethylcyclo- pentane-1 -carbaldehyde.

[0298] 3eg=eguivalent, relative to ((1S,2R,4S)-2,3,3,4-tetramethylcyclopen- tane-1-carbaldehyde. DABCO has been added with ammonium salt of amine (ASA6)

[0299] Fourth series: Dehydrogenation using different cobalt complexes (CC) and different photocatalysts (PC) at different temperatures and concentrations and wavelengths

[0300] The dehydrogenation has been performed using the described general procedure conversion and yield are reported in table 4.

[0301] A Tjrr Cone. Conv. Yield Ex. PC1CC2PC / CC / ASA4

[0302] [nm] [°C] [M]3[%15[%]536 (PC2) (CC11) 451 25 0.5 2500 / 25000 / 100000 73 58 37 (PC2) (CC11) 427 25 0.5 2500 / 25000 / 100000 71 55 38 (PC2) (CC1) 427 25 0.5 2500 / 25000 / 100000 60 43 39 (PC2) (CC7) 427 25 0.5 2500 / 25000 / 100000 70 52 40 (PC6) (CC7) 427 25 0.5 2500 / 25000 / 100000 79 63 41 (PC6) (CC7) 427 25 0.5 2500 / 25000 / 100000 85 68 42 (PC6) (CC11) 427 25 0.8 2500 / 25000 / 100000 78 63 43 (PC6) (CC11) 427 25 0.5 1 500 / 2500 / 100000 78 66 44 (PC6) (CC11) 427 25 0.5 1 500 / 2500 / 100000 65 55 45 (PC6) (CC11) 427 50 1 1 500 / 2500 / 100000 51 27 46 (PC14) (CC11) 427 25 0.5 2500 / 25000 / 100000 68 57 47 (PC6) (CC11) 427 25 0.5 5000 / 5000 / 100000 90 78 48 (PC6) (CC11) 420 10 0.5 5000 / 5000 / 100000 89 79 58 (PC6) (CC15) 427 25 1 2500 / 2500 / 150000 80 61

[0303]

[0304] Tab e 4. Dehydrogenation of 16 mmol (7S;2R;4S)-2,3,3,4-tetramethylcyclopen- tane-1-carbaldehyde in acetonitrile using different cobalt complexes- 29 - 2024P00183WO (CC), photocatalyst (PC), and ammonium salt (ASA) of the formula (ASA6)

[0305] 1PC: Photocatalyst of the formula

[0306] 2CC: Cobalt complex of the formula

[0307] 3Concentration of 7S;2R;4S)-2,3,3,4-tetramethylcyclopentane-1- carbaldehyde in acetonitrile

[0308] 4molar ratio in ppm relative to the substrate of PC / CC / ASA determined by GC, relative to (1S,2R,4S)-2,3,3,4-tetramethylcyclo- pentane-1 -carbaldehyde.

[0309] Fifth series: Dehydrogenation at different concentrations

[0310] A round bottom flask was charged under argon with (1 S,2R,4S)-2,3,3,4-tetramethylcyclopentane-1-carbaldehyde (1.928g, 12.5 mmol) followed by photocatalyst (PC) of the formula (PC6), followed by cobalt complex (CC) of the formula (CC11 ), followed by ammonium salt (ASA) of the formula (ASA6) dissolved in acetonitrile. The reaction mixture was irradiated at 420 nm under inert atmosphere at different temperatures. After 23h the irradiation was stopped and the reaction mixture was analyzed for the formation of (S)-2, 3,3,4-tetramethylcyclopent-1-ene-1-carbaldehyde and the results are shown and reported in table 5.

[0311] Cone. Conv. Yield Example. PC / CC / ASA4

[0312] [M]3[%]5[%]549 0.5 2 500 / 25 000 / 100 000 100 90 50 1 1 500 / 1 500 / 100000 91 79 51 1 1 000 / 1 000 / 100000 89 74 52 0.5 1 500 / 1 500 / 100000 88 72 53 0.6 1 500 / 1 500 / 100000 95 76

[0313]

[0314] Table 5. Dehydrogenation of 7S;2R;4S)-2,3,3,4-tetramethylcyclopentane-1- carbaldehyde in acetonitrile using cobalt complexes (CC) of the formula (CC11), photocatalyst (PC) of the formula (PC6), and ammonium salt (ASA) of the formula (ASA6).

[0315] 3Concentration of 7S;2R;4S)-2,3,3,4-tetramethylcyclopentane-1- carbaldehyde in acetonitrile

[0316] 4molar ratio in ppm relative to the substrate of PC / CC / ASA determined by GC, relative to (1S,2R,4S)-2,3,3,4-tetramethylcyclo- pentane-1 -carbaldehyde.Sixth series: Dehydrogenation at different wavelengths

[0317] The dehydrogenation has been performed using the described general procedure at Tirr = 25°C. Conversion and yield are reported in Table 6.

[0318] Conv.

[0319] Ex. PC1CC2A [nm] PC / CC / ASA3Yield [%]4

[0320] [%]4

[0321] 50 (PC6) (CC11) 427 1 500 / 1 500 / 100000 91 79 54 (PC6) (CC11) 390 1 500 / 1 500 / 150000 66 40

[0322]

[0323] Table 6. Dehydrogenation of (TS,2R,4S)-2,3,3,4-tetramethylcyclopentane-1- carbaldehyde in acetonitrile (1M) using the cobalt complex of formula (CC11), the photocatalyst of formula (PC6), and ammonium salt of an amine (ASA) of the formula (ASA6) at different wavelengths

[0324] 1PC: Photocatalyst of the formula

[0325] 2CC: Cobalt complex of the formula

[0326] 3molar ratio in ppm relative to the substrate of PC / CC / ASA determined by GC, relative to (1S,2R,4S)-2,3,3,4-tetramethylcyclopen- tane-1 -carbaldehyde.

[0327] Seventh series: Dehydrogenation using different photocatalysts (PC)

[0328] A 10-mL glass reactor was charged under argon with (1S,2R,4S)-2, 3,3,4-tetramethylcyclopentane-1 -carbaldehyde (771.25 mg, 5 mmol) followed by photocatalyst (PC) of formula (PC6), by the cobalt catalyst of formula (CC11 ), and by the ammonium salt of the amine of formula (ASA6) in the molar ratio (in ppm) relative to the substrate indicated in Table 7. The reaction mixture was dissolved in acetonitrile (1M). The reaction mixture was irradiated at a wavelength of 427 nm under inert atmosphere at a temperature Tirr= 25°C. After 23 hours, the irradiation was stopped, and the reaction mixture was analysed. The conversion and yield are reported in Table 7.

[0329] Ex. PC1CC2PC / CC / ASA3Conversion [%]4Yield [%]450 (PC6) (CC11) 1 500 / 1 500 / 100000 91 79 55 (PC6) (CC11) 1 500 / 1 500 / 0 33 5

[0330]

[0331] Table 7. Dehydrogenation of (1S,2R,4S)-2,3,3,4-tetramethylcyclopentane-1- carbaldehyde in acetonitrile (1M) using the cobalt complex of formula (CC11), the photocatalyst of formula (PC6), and ammonium salt of an amine (ASA) of the formula (ASA6)

[0332] 1PC: Photocatalyst of the formula

[0333] 2CC: Cobalt complex of the formula

[0334] 3molar ratio in ppm relative to the substrate of PC / CC / ASA determined by GC, relative to (1S,2R,4S)-2,3,3,4-tetramethylcyclopen- tane-1 -carbaldehyde.

[0335] 5TBADT = tetra-n-butylammonium decatungstate- 31 - 2024P00183WC As seen in Table 7, the use of the ammonium salt of an amine (ASA) led to significantly improved conversion and yield of the dehydrogenation reaction, compared to the equivalent reaction in the absence of the ammonium salt of an amine (ASA).

[0336] Eighth series: Comparative dehydrogenation example using different photocatalysts (PC)

[0337] A 10-mL glass reactor was charged under argon with (1S,2R,4S)-2, 3,3,4-tetramethylcyclopentane-1-carbaldehyde (771.25 mg, 5 mmol) followed by photocatalyst (PC) as indicated in Table 8, the cobalt catalyst of formula (CC11), and the ammonium salt of the amine of formula (ASA6) in the molar ratio (in ppm) relative to the substrate indicated Table 8. The reaction mixture was dissolved in acetonitrile (1M). The reaction mixture was irradiated at a wavelength of 427 nm under inert atmosphere at a temperature Tirr= 25°C. After 23 hours, the irradiation was stopped, and the reaction mixture was analysed. The conversion and yield are reported in Table 8.

[0338] Conversion Yield Ex. PC1CC2PC / CC / ASA3

[0339] [%]4[%]450 (invention) (PC6) (CC11) 1 500 / 1 500 / 100000 91 79 56

[0340] TBADT5(CC11) 1 500 / 1 500 / 150000 27 2 (comparative)

[0341] 57 1 500 / 1 500 / 0

[0342] TBADT5(CC11) 69 8 (comparative)

[0343]

[0344] Table 8. Dehydrogenation of (1S,2R,4S)-2,3,3,4-tetramethylcyclopentane-1- carbaldehyde in acetonitrile (1M) using the cobalt complex of formula (CC11), different photocatalysts (PC), and ammonium salt of an amine (ASA) of the formula (ASA6)

[0345] 1PC: Photocatalyst of the formula

[0346] 2CC: Cobalt complex of the formula

[0347] 3molar ratio in ppm relative to the substrate of PC / CC / ASA determined by GC, relative to (1S,2R,4S)-2,3,3,4-tetramethylcyclopen- tane-1-carbaldehyde.

[0348] 5TBADT = tetra-n-butylammonium decatungstate

[0349] As seen in Table 8, the use of a photocatalyst (PC6) and an ammonium salt of an amine (ASA6) according to the invention led to high conversion and yield of the dehydrogenation reaction, whereas the use of photocatalyst TBADT (comparative examples) led to poorer conversion and low yield.Ninth series: Examples of dehydrogenation of further alpha-beta olefinically unsaturated aldehydes or ketones

[0350] Dehydrogenation of cyclopentane-1 -carbaldehyde

[0351] A 10-mL glass reactor was charged under argon with cyclopentane-1 -carbaldehyde (1.8 mmol) followed by photocatalyst of formula (PC6), by the cobalt catalyst of formula (CC2), and by the ammonium salt of the amine of formula (ASA6) in the molar ratio (in ppm) relative to the substrate of PC / CC / ASA = 50 000 / 50 000 / 200 000. The reaction mixture was dissolved in acetonitrile (0.2M). The reaction mixture was irradiated at a wavelength of 427 nm under inert atmosphere at a temperature Tirr= 25°C. After 23 hours, the irradiation was stopped, and the reaction mixture was analysed for the formation of cyclopent-1-ene-1-carbaldehyde. The conversion was of 81% and the yield was of 39%, as determined by GC, relative to the substrate, cyclopentane-1 -carbaldehyde.

[0352] 1H NMR (300 MHz, CDCl3): δ = 9.78 (1H, s, CHO), 6.88–6.85 (1H, m, CH), 2.64–2.49 (4H, m, CH2CH, CH2CHO), 1.99 (2H, qu, J 7.6, CH2)

[0353] 13C NMR (100 MHz, CDCl3) δ 190.04, 153.30, 148.05, 33.81, 28.44, 23.05

[0354] Dehydrogenation of cyclohexane-1 -carbaldehyde

[0355] A 10-mL glass reactor was charged under argon with cyclopentane-1 -carbaldehyde (1.8 mmol) followed by photocatalyst of formula (PC6), by the cobalt catalyst of formula (CC11 ), and by the ammonium salt of the amine of formula (ASA6) in the molar ratio (in ppm) relative to the substrate of PC / CC / ASA = 50 000 / 50 000 / 200 000. The reaction mixture was dissolved in acetonitrile (0.2M). The reaction mixture was irradiated at a wavelength of 427 nm under inert atmosphere at a temperature 7 / ff= 25°C. After 23 hours, the irradiation was stopped, and the reaction mixture was analysed for the formation of cyclohex-1 -ene-1 -carbaldehyde. The conversion was of 60% and the yield was of 34%, as determined by GC, relative to the substrate, cyclohexane-1 -carbaldehyde.1H NMR (300 MHz, C6D6) 6: 9.26 (s, 1 H, CHO), 5.99 (m, 1 H, H-2), 2.16 - 2.11 (m, 2H, H-6), 1.72 - 1.66 (m, 2H, H-3), 1.27 - 1.21 (m, 2H, H-5), 1.23 - 1.16 (m, 2H, H-4).

[0356] 13C NMR (100 MHz, C6D6) 5: 192.9 (CHO), 149.3 (C-2), 141.8 (C-1), 26.2 (C-3), 22.2 (C-4), 21.6 (C-6), 21.5 (C-5)

[0357] Dehydrogenation of cyclododecane-1 -carbaldehyde

[0358] A 10-mL glass reactor was charged under argon with cyclopentane-1 -carbaldehyde (1.8 mmol) followed by photocatalyst of formula (PC6), by the cobalt catalyst of formula (CC11 ), and by the ammonium salt of the amine of formula (ASA6) in the molar ratio (in ppm) relative to the substrate of PC / CC / ASA = 50 000 / 50 000 / 200 000. The reaction mixture was dissolved in acetonitrile (0.2M). The reaction mixture was irradiated at a wavelength of 427 nm under inert atmosphere at a temperature 7 / ff= 25°C. After 23 hours, the irradiation was stopped, and the reaction mixture was analysed for the formation of (E)-cyclododec-1-ene-1 -carbaldehyde. The conversion was of 65% and the yield was of 39%, as determined by GC, relative to the substrate, cyclododecane-1 -carbaldehyde.

[0359] 1H NMR (300 MHz, CDCl3): δ = 9.36 (1H, s, CHO), 6.47 (1H, t, J 7.7, CH), 2.35 (2H, q, J 7.7, CH2CH), 2.24 (2H, t, J 7.3, CH2CCHO), 1.56–1.23 [22H, m, (CH2)11]

[0360] 13C NMR (100 MHz, CDCl3) δ 196.0, 155.9, 143.5, 26.3, 26.0, 25.8, 25.3, 24.9, 24.8, 23.6, 23.0, 22.2, 21.6

Claims

Claims:

1. A process of producing an alpha-beta olefinical ly unsaturated aldehyde or ketone (UAK) by photodehydrogenation of an aldehyde or a ketone (AK) in the presence of- at least one cobalt complex (CC);- at least a photocatalyst (PC) being an organic photocatalyst, preferably a cyanoarene polyaromatic photocatalyst, or an iridium complex;- at least one amine (A) or an ammonium salt (ASA) of the at least one amine (A) and an organic or inorganic acid;- light.

2. The process according to claim 1 characterized in that the aldehyde or a ketone (AK) is a compound of the formula (I) and the alpha-beta olefinically unsaturated aldehyde or ketone (UAK) is of the formula (II)wherein W represents 0, S, NR, or R3R3; andR4R4W represents 0, S, NR, orwherein R represents a Ci- -alkyl group or Ce-12-aryl group or Ce-12- aralkyl group or a "__so2Arwith Ar being a Ce-12-aryl group, preferably a p-tolyl group;with the proviso, that either W or W, are different from 0, S, or NR;X representseitherH or a Ci-w-alkyl group or a C6-i2-cycloalkyl group or a Ce-12-aryl group;orforms together with at least one substituent of the group consisting of R1, R2, R3, R3, R4, R4, R5, R5, R6, R6, R7, R7'and R8an alkylene group yielding a 5- to 12-membered ring; andR1, R2, R3, R3, R4, R4, R5, R5, R6, R6, R7, R7'and R8, independently from each other,either,represent H, a Ci- -alkyl group or a Ce-12-aryl group; particularly H or CH3;orform together with X or with at least one other substituent of the group consisting of R1, R2, R3, R3, R4, R4, R5, R5, R6, R6, R7, R7' and R8an alkylene group yielding a 5- to 12-membered ring, n1, n2 and n3, independently from each other, represent each a value of 0 or 1 or 2 or 3;and wherein any wavy line represents a carbon-carbon bond which when linked to the carbon-carbon double bond is either in the Z- or in the E-configuration.

3. The process according to claim 2, characterized in that the compound of the formula (II) is a compound of the formula (ll-Cy-l)(Il-Cy-I).

4. The process according to claim 2, characterized in that the compound of the formula (II) is a compound of the formula (l-Cy-ll)5. The process according to any of the preceding claims 2 -4, characterized in that R2Is different from H.

6. The process according to any one of claims 1 to 3 or 5, characterized in that the aldehyde or a ketone (AK) and the alpha-beta olefinically unsaturated aldehyde or ketone (UAK) is an aldehyde.

7. The process according to any of the preceding claims, characterized in that the cobalt complex (CC) is a Co(ll) or Co(lll) complex, preferably that the cobalt complex comprises at least one organic ligand, preferably a chelating ligand, particularly ligands having the structural element of C=N, more preferably an oxime, which is bound via nitrogen atom to the cobalt.

8. The process according to any of the preceding claims, characterized in that the cobalt complex (CC) is a cobalt complex selected from the group consisting of the cobalt complexes of the formula (CC1 ), (CC2), (CC3), (CC4), (CC5), (CC5), (CC6), (CC7), (CC8), (CC9), (CC10), (CC11), (CC12), CC(13), (CC14) and (CC15)(CC1) (CC3)(CC4)(CC9)(CC11)(CC13) (CC14). (CC15)9. The process according to any of the preceding claims, characterized in that photocatalyst (PC) is an iridium complex, preferably an iridium complex which comprises at least a ligand from the group consisting ofwhereinY1, Y1', Y2, Y2', Y and Y3', independently from each other, represents H, a Ci -4-alkyl group or a halogenated Ci -4-alkyl group or a halide or a C1-4 alkoxy group;and wherein * marks the atom of the ligand which is bound to the iridium center.

10. The process according to any of the preceding claims, characterized in that photocatalyst (PC) is an iridium complex which complex is selected from the group consisting of the compounds of the formula (PC1 ), (PC2), (PC3), (PC4), (PC5), (PC6), (PC7) and (PC8)(PC1)(PC3)(PC5)(PC7)11. The process according to any of the preceding claims, characterized in that the photocatalyst (PC) is an organic photocatalyst, preferably an organic photocatalyst selected from the group consisting of cyanoarenes, benzophenones, quinones, pyryliums, thiapyryliums, quinoliniums, acridiniums, xanthene dyes, rhodamines, phenothiazines and polyaromatic photocatalysts; more preferably a cyanoarene polyaromatic photocatalyst.

12. The process according to any of claims 1 to 8 or 11, characterized in that the organic photocatalyst is a compound of the formula (PCO)(PCO)wherein A1, A2, A3, A4and A5, independently from each other, represents either a halide, CN or an aromatic secondary amino group, particularly of the formula (B1), particularly of the formula (B2)(B1) (B2) Ar1' Tkr2wherein Ar1and Ar2represent either a phenyl or a substituted phenyl groups or form together a bridged di-phenylic group;Z1and Z2, independently from each other, represents represent either H, a halide or a Ci-4-alkyl group or a Ci-4-alkoxy group;and any dotted single line in any formulae represents the bond by which said substituent is bound to the rest of a molecule;with the proviso, thatat least one of the substituents A1, A2, A3, A4and A5is an aromatic secondary amino group;and not more than two of the substituents A1, A2, A3, A4and A5are halides.

13. The process according to any of claims 1 to 8, 11 or 12, characterized in that the photocatalyst (PC) is a cyanoarene polyaromatic photocatalyst, which is selected from the group consisting of the compounds of the formula (PC9), (PC10), (PC11), (PC12), (PC13), (PC14), (PC15), (PC16) and (PC17)14. The process according to any of the preceding claims, characterized in that the at least one amine (A) is a primary amine or a secondary amine, preferably a secondary amine selected from the group consisting of the formula (Ai) or (Aii)whereinQ represents CH2or CH2CH2or O or S or NQ3;Q1, Q1', Q2and Q2', independently from each other, represents H, or a C1-4- alkyl group or a carboxyl group;Q3represents H or a Ci-4-alkyl group, preferably a methyl group; more preferably a secondary amine selected from the group consisting of pyrrolidine, piperidine, piperazine, methyl piperazine, morpholine, thiomorpholine and proline;or an ammonium salt of said amine (Ai) or (Aii) and an organic or inorganic acid.

15. The process according to any of the preceding claims, characterized in that the amine (A) or an ammonium salt (ASA) of the at least one amine (A) and an organic or inorganic acidis an ammonium salt (ASA) of an amine (A) and an organic or inorganic acid;preferably an ammonium salt (ASA) of morpholine or methyl piperazine and an organic or inorganic acid;more preferably an ammonium salt (ASA) selected from the group consisting of the compounds of the formula (ASA1), (ASA2), (ASA3), (ASA4), (ASA5), and (ASA6)(ASA2)(ASA3)(ASA5)16. The process according to any of the preceding claims, characterized in that the light is a light of the wave lengths of between 300 and 500 nm, preferably between 365 and 460 nm, particularly between 400 and 460 nm.

17. A composition for comprising at leasta) a cobalt complex (CC);b) a photocatalyst (PC) being an organic photocatalyst or an iridium complex; c) an amine (A) or an ammonium salt (ASA) of the amine (A) and a carboxylic or inorganic acidd) an aldehyde or a ketone (AK).

18. The use of a composition comprising at leasta) a cobalt complex (CC);b) a photocatalyst (PC) being a cyanoarene polyaromatic photocatalyst or an iridium complex;c) an amine (A) or an ammonium salt (ASA) of the amine (A) and a carboxylic or inorganic acid;for the photodehydrogenation of an aldehyde or a ketone (AK).

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