WO2010040939A1

WO2010040939A1 - Novel method for the metathesis of olefins or enynes

Info

Publication number: WO2010040939A1
Application number: PCT/FR2009/051891
Authority: WO
Inventors: Didier Astruc; Jaime Ruiz Aranzaes; Abdou Diallo; Elodie Boisselier
Original assignee: Centre National De La Recherche Scientifique
Priority date: 2008-10-08
Filing date: 2009-10-05
Publication date: 2010-04-15
Also published as: FR2936799A1

Abstract

The present invention relates to a novel method for the metathesis of olefins or enynes. The invention also relates to the dendrimers for implementing novel methods.

Description

NOVEL PROCESS FOR THE METATHESIS OF OLEFINS OR ENYNES

The present invention relates to a new process for the metathesis of olefins or enynes. It also relates to dendrimers for the implementation of new processes. The metathesis reaction of olefins, the importance of which was highlighted by the award of the Nobel Prize in 2005 to Y. Chauvin, R. H. Grubbs, and R. R. Schrock, allows the transformation of hydrocarbons and unsaturated organic derivatives with a high added value.

There are different types of olefin metathesis such as cross metathesis (CM), ring closure metathesis (RCM), acyclic diene metathesis polymerization (ADMEP), ring opening metathesis polymerization (ROMP) ), metathesis of enynes, cross-metathesis and ring-opening (ROCM).

These reactions are carried out using a metal-containing molecular catalyst, especially ruthenium.

Several catalysts have been developed to carry out these reactions, in particular the first-generation Grubbs catalyst (Grubbs et al., J. Am Chem Soc, 1996, 118, 100-

110), the second-generation Grubbs catalyst (Grubbs et al., Organic Letters, 1999, 1 (6),

953-956), or the first and second generation Hoveyda-Grubbs catalysts (Hoveyda et al, J. Am Chem Soc, 1997, 119, 1488-1489 and 2000, 122, 8158-8179), all commercial .

However, these catalysts have the disadvantage of being soluble only in organic solvents, which presents a certain incompatibility with the concept of sustainable development, thus limiting the industrialization of processes using them.

The development of processes using water as a solvent therefore represents a major challenge, particularly for the environment, but faces the lack of solubility of the catalysts in the water. In addition, most of the olefins generally used in these reactions are insoluble in water.

To circumvent this problem of solubility, water-soluble catalysts have been developed (Grubbs et al., J. Am Chem Soc, 1998, 120, 1627-1628 and 2000, 122, 6601-6609) but of a On the other hand, these processes require the use of large quantities of catalysts, on the other hand, either these processes are limited to certain metathesis reactions, or they can be carried out only with water-soluble olefins, the product of which obtained by the metathesis reaction is then difficult to separate from the catalyst. To overcome the solubility problems of olefins in water, Grêla et al. (Green

Chemistry, 2008, 10, 279-282) used ultrasound to make water insoluble substrates compatible with water as the solvent, using a catalyst amount of 5 mol%. However, the use of ultrasound makes the process difficult to use on an industrial scale, and the amount of catalyst used remains important.

Lipshutz et al. (Organic Letters, 2008, 10, 1325-1328 and Adv Synth Synth., 2008, 350,

953-956) have described the use of 2.5% PTS (Peg-600 / diester

Tocopherol), in the presence of 2 mol% of Grubbs 2 catalyst to perform metathesis reactions (RCM, ROMP and CM) in water. However, TPS has the disadvantage of contaminating the desired formed product.

It is also described (Astruc et al, Angew Chem Int.Ed., 2003, 42, 452-456) the use of dendrimers comprising a covalently linked catalyst to perform metathesis reactions (ROMP), however these reactions require the use of organic solvent. Dendrimers are molecules with several branches whose shape resembles that of the branches of a tree. They have been used for different applications, such as micelles, molecular dishes, exoreceptors or drug vectors.

One aspect of the present invention is to provide a method of metathesis in water compatible with sustainable development. Another aspect of the present invention is to provide a method of metathesis that does not systematically require operating under an inert atmosphere.

Yet another aspect of the present invention is to provide a metathesis method, applicable regardless of the type of metathesis.

Another aspect of the invention is to provide a metathesis process wherein the reaction products are not contaminated by the dendrimer or the catalyst.

Another aspect of the invention is to provide novel dendrimers for metathesis.

Another aspect of the present invention is to provide a metathesis process in which the dendrimer and catalyst are both recyclable.

Finally, another aspect of the invention is to use the ruthenium catalyst in a much smaller amount than in the literature for ring closure metathesis, whether in an inert atmosphere or on the contrary in air. Accordingly, the present invention relates to the use of at least one water-soluble amphiphilic dendrimer and at least one ruthenium catalyst for carrying out metathesis reactions of olefins or enynes in an aqueous medium. without organic solvent. It has been found that the use of an amphiphilic dendrimer and a catalyst, at lower concentrations than those used to date for ring closure metathesis, made it possible to do any type of metathesis in the water, both inert atmosphere and air, with acceptable yields and to recycle the catalyst and the dendrimer. By "amphiphilic dendrimer" is meant a dendrimer having both hydrophobic groups within the dendrimer and amphiphilic ends having affinity for the substrate. Thus, the dendrimer behaves like a molecular micelle.

The hydrophobic group may be for example an aromatic compound, such as a phenyl or a heterocycle, or a long carbon chain of 5 to more than 16 carbons.

The amphiphilic ends may be a molecule itself amphiphilic such as for example a PEG (polyethylene glycol).

The term "water-soluble" refers to a substance that is soluble in water.

The term "ruthenium catalyst" refers to any ruthenium-containing catalyst that can be used in metathesis reactions, and used in a catalytic, i.e. non-stoichiometric, amount.

By the term "olefin" is meant any cyclic olefin which may be subject to a ring opening metathesis polymerization reaction (ROMP), or any terminal olefin susceptible to metathesis reactions. cross-linked (CM) with itself or with a different terminal olefin, or any ring-cleavable diene (RCM) or acyclic diene metathesis polymerization (ADMEP), or any olefin terminally or non-susceptible to a cross-metathesis and ring-opening reaction (ROCM) by reaction with a cyclic olefin to yield an olefin.

By the term "enyne" is meant any molecule comprising both an olefin, terminal or non-terminal, and a triple bond, terminal or non-terminal to an olefin. By the expression "in an aqueous medium", it should be understood that the reactions are carried out strictly in water, without the addition of any cosolvent, even miscible with water such as acetone, tetrahydrofuran, dioxane, dimethylformamide, dimethoxyethane or PEG-500 dimethyl ether. The catalyst may be covalently bonded to the dendrimer, subject to the presence of amphiphilic termini at the ends of the dendrimer.

The dendrimer may also contain ruthenium which has no catalytic function.

By the term "without organic solvent" it should be understood that in addition to the co-solvents mentioned above, no other solvent than water is used to carry out the reaction.

Therefore, one of the advantages of the present invention is to be able to implement a metathesis reaction regardless of the olefin used and regardless of its nature (water-soluble or non-water-soluble), under conditions compatible with Sustainable development.

In an advantageous embodiment, the present invention relates to the use of at least one amphiphilic dendrimer, water-soluble, and at least one ruthenium catalyst as defined above, said dendrimer and said catalyst being not associated covalently.

The term "catalyst and dendrimers not being covalently associated" means that there is no covalent bond between the catalyst and the dendrimer, but that both are present in the medium.

In an advantageous embodiment, the present invention relates to the use of at least one water-soluble amphiphilic dendrimer and at least one ruthenium catalyst for the implementation of metathesis reactions of olefins or enynes. in an aqueous medium, without an organic solvent, said ruthenium catalyst being insoluble in water. Another advantage of the present invention is therefore to be able to use any ruthenium catalyst, including a commercial catalyst, although it is not soluble in water.

In an advantageous embodiment, the present invention relates to the use of at least one water-soluble amphiphilic dendrimer and at least one ruthenium catalyst for the implementation of metathesis reactions of olefins or enynes. in an aqueous medium, without organic solvent, said olefins or enynes being insoluble in water. Yet another advantage of the present invention is that it can perform the metathesis reactions regardless of olefins, although said olefins are insoluble in water, unlike most of the metathesis processes heretofore described.

According to an advantageous embodiment, the present invention relates to the use of at least one amphiphilic, water-soluble dendrimer and at least one ruthenium catalyst, for the implementation of metathesis reactions of olefins or enynes. in an aqueous medium, without an organic solvent, said metathesis reaction being carried out under an inert atmosphere, in particular under nitrogen.

The inert atmosphere of said reaction is carried out at atmospheric pressure and avoids the degradation of the catalyst which is sensitive to air and decomposes in its presence.

According to a more advantageous embodiment, the present invention relates to the use of at least one water-soluble amphiphilic dendrimer and at least one ruthenium catalyst for carrying out metathesis reactions of olefins or of enynes, in an aqueous medium, without organic solvent, wherein said metathesis reaction is carried out under an atmosphere consisting of air.

Another advantage of the present invention lies in the fact that the catalyst, under the conditions used, is protected from the degradation induced by the air, thus making it possible to carry out the reactions in the presence of air, without using an excess of catalyst , unlike the methods heretofore described.

According to another advantageous embodiment, the present invention relates to the use of at least one water-soluble amphiphilic dendrimer and at least one ruthenium catalyst, for carrying out olefin metathesis reactions or enynes, in aqueous medium, without organic solvent, the said metathesis reaction is carried out in a temperature range of about 20 ⁰ C to about 65 ° C, preferably from 40 ⁰ C to 60 ⁰ C, in particular about 20 ⁰ At about 40 ^° C., in particular from about 20 ° to about 25 ° C.

To fix the ideas, the cycle closure metatheses (RCM of olefins and enynes) and the ring opening metathesis (olefin ROMP) are carried out from 20 ⁰ C to 40 ⁰ C and the crossed metatheses ( CM) are carried out at 40 ^° C. to 65 ° C. Another advantage of the present invention is therefore to carry out the majority of metathesis reactions at ambient temperature, in particular the RCMs of olefins or enynes and the ROMPs, under an inert atmosphere or in air.

Being in an inert atmosphere reduces only slightly the amount of catalyst relative to the reaction to air.

According to a more advantageous embodiment, said ruthenium catalyst, used with said dendrimer, defined above, is a catalyst of Grubbs 1 or 2, or Hoveyda-Grubbs 1 or 2, in a proportion of about 0.01 mole% to 5 mole%.

Grubbs catalysts 1 or 2 or Hoveyda-Grubbs 1 or 2 are commercial compounds, especially in a supplier such as Sigma-Aldrich.

The catalysts defined above are used in different proportions depending on the type of metathesis reaction performed.

Below 0.01%, the reactions are performed with too low efficiency or no longer work. Above 5%, the quantities used are useless for the reaction efficiency and too important to be used industrially, whether it is the high cost or problems related to waste treatment.

In an advantageous embodiment, said catalyst employed with said dendrimer, as defined above, is used in a proportion of about 0.04 mol% to about 0.2 mol%, preferably about 0.1 mol%. mole

The catalyst concentrations used make it possible to carry out metathesis reactions of the RCM or ROMP type under an inert atmosphere.

Below 0.04%, the reaction is no longer carried out.

Above 0.1% under an inert atmosphere, the yields obtained are almost quantitative and do not require an increase in the amount of the catalyst.

Example 5 and Table I below present in the results of this example show that a ruthenium catalyst, for example the Grubbs 2 catalyst, at room temperature, under an inert atmosphere, makes it possible to carry out cyclizations of various olefins, insoluble in water, with good yields using as little catalyst as 0.06 mol%. Therefore, another advantage of the present invention lies in the fact that in the context of metathesis reactions of the RCM or ROMP type, the metathesis reactions which are most commonly used in organic synthesis, the proportion of catalyst used is less than 30 times that used until now in metathesis processes under inert atmosphere.

It has been shown that the use of as little as 0.04% of catalyst with the substrate 3, also leads to the product 7 with a yield of 66%.

However, the reaction is longer and requires a reaction time of 72 hours.

In an advantageous embodiment, said catalyst used with said dendrimer, as defined above, is used in a proportion of about 0.1 mol% to about 0.3 mol%, preferably about 0.15 mol%. mole at about 0.25 mole%, especially about 0.2 mole%.

The catalyst concentrations used make it possible to carry out metathesis reactions of the RCM or ROMP type under an atmosphere consisting of air. Below 0.1%, the reaction is not as effective.

Above 0.2%, the yields obtained are almost quantitative and do not require an increase in the amount of the catalyst.

It has been shown that the Grubbs 2 catalyst, at ambient temperature, under an atmosphere consisting of air, makes it possible to carry out cyclizations of various olefins, which are insoluble in water, with high yields, of the order of 98.degree. %, using as little catalyst as 0.2 mol%.

Therefore, another advantage of the present invention lies in the fact that in the context of RCM or ROMP type metathesis reactions, the proportion of catalyst used is 10 times lower than that used until now in the processes under inert atmosphere and that the present invention therefore allows a protective effect of the catalyst against the degradation induced by air.

In an even more advantageous embodiment, said catalyst employed with said dendrimer, as defined above, is used in a proportion of from about 1 mol% to about 3 mol%, preferably from about 1.5 mol% to about 1 mol%. about 2.5 mol%, especially about 2 mol%. The catalyst concentrations used make it possible to carry out CM type metathesis reactions under an inert atmosphere.

Below 1%, the reaction is not as effective.

Above 3%, the yields obtained are almost quantitative and do not require an increase in the amount of the catalyst.

It has been shown that a ruthenium catalyst, for example the Grubbs 2 catalyst, at room temperature, under an inert atmosphere, makes it possible to proceed to cyclizations of various enynes, insoluble in water, with high yields (> 97%) using a catalyst amount of 2 mol%. In an even more advantageous embodiment, said catalyst employed with said dendrimer, as defined above, is used in a proportion of about 1 mol% to about 3 mol%, preferably about 2 mol% to about 3 mol%. mol%, in particular about 2 mol%.

The catalyst concentrations used make it possible to carry out RCM-type metathesis reactions in an atmosphere consisting of air.

Below 1%, the reaction is no longer carried out.

In an even more advantageous embodiment, said catalyst employed with said dendrimer, as defined above, is used in a proportion of about 1 mol% to about 5 mol%, preferably about 2 mol% to about 5 mol%. mol%, in particular about 2 mol%.

The catalyst concentrations used make it possible to carry out CM type metathesis reactions under an inert atmosphere. Below 1%, the reaction is not as effective.

Above 5%, the quantities used are too important to be used industrially, whether it is the high cost or problems related to the treatment of waste.

It has been shown that a ruthenium catalyst, for example the Grubbs 2 catalyst, at 40 ^° C., under an inert atmosphere, makes it possible to proceed to cyclizations of various enynes, which are insoluble in water, with acceptable yields ( 66%) using a catalyst amount of 2 mol%. In an even more advantageous embodiment, said catalyst employed with said dendrimer, as defined above, is used in a proportion of about 3 mol% to about 5 mol%, preferably about 4 mol% to about 5 mol%. mol%, in particular about 5 mol%.

The catalyst concentrations used make it possible to carry out CM type metathesis reactions in an atmosphere consisting of air.

Below 1%, the reaction is not as effective. Above 5%, the quantities used are too important to be used industrially, whether it is the high cost or problems related to the treatment of waste.

In an even more advantageous embodiment, said catalyst employed with said dendrimer, as defined above, are reusable, at the end of the first metathesis reaction, for a subsequent metathesis reaction, in particular in at least one reaction of subsequent metathesis to about ten subsequent metathesis reactions, preferably in at least one to about 5, particularly in at least one to three.

The product formed at the end of the metathesis reaction can be extracted from water after filtration by an organic solvent, it remains in water the soluble amphiphilic dendrimer and on the filter and the walls of the reaction vessel, the catalyst insoluble in water. The catalyst and the dendrimer can be reacted with the same or a different substrate. Therefore, one of the advantages of the invention is to be able to recycle both the catalyst and the dendrimer, thereby reducing the cost of synthesis as well as having the advantage of being compatible with sustainable development.

In an even more advantageous embodiment, said dendrimer employed with said catalyst, defined above, is used in a proportion of about 0.01 mol% to about 0.1 mol%, preferably about 0.01 mol%. mole to about 0.05%, more preferably about 0.01 mole% to about 0.03 mole%, still more preferably about

0.015 mol% to about 0.025 mol%, particularly about 0.02 mol%.

Therefore, another advantage of the present invention is that in the metathesis reactions described above regardless of their type, and the conditions used (inert atmosphere or air), the proportion of catalyst used is less than 30%. to 10 times that used until now in the processes under respectively inert atmosphere or in air, and comprising a quantity of dendrimer as low as 0.02 mol%, 60 times lower than that used in the processes.

Below 0.01 mol%, the concentration of dendrimers is no longer effective for carrying out the reaction. Above 0.1%, the proportion becomes too important for an industrial synthesis of the products.

In an advantageous embodiment, said dendrimer used with said catalyst defined above, is chosen from commercial dendrimers or their derivatives, on which PEG has been grafted, in particular PAMAM and DAB. In an advantageous embodiment, said dendrimer used with said catalyst, defined above, corresponds to the following general formula (I):

A - [(L) _r B] _x (I) in which A corresponds to a hydrophobic core, L corresponds to an optionally present spacer, and B corresponds to an amphiphilic part comprising a dendron consisting of amphiphilic terminations, x corresponds to a number integer ranging from 2 to 6, i corresponds to an integer from 0 to 1, and said dendrimer having a molecular weight of from 5000 to 90000, preferably from 7212 to 76509, more preferably from 8787 to 28153, still more preferably from 8787 to 23349 and a hydrophilic-lipophilic balance (HLB) of from 14 to 20, in particular from 15.59 to 17.41.

By "hydrophobic core", it is necessary to understand the central part of the dendrimer (the core) comprising hydrophobic groups chosen from those defined above.

The term "spacer" refers to a sequence of atoms, the length of which can vary and which can be repeated several times, to separate the dendrons of the hydrophobic core and to multiply the number of chains linked to the hydrophobic core.

In the term "amphiphilic terminations" the term "amphiphile" has the same meaning as above.

The expression "hydrophilic-lipophilic balance" designates the ratio between the hydrophilic groups and the lipophilic groups corresponding to a semi empirical scale that ranges from 1 to 40. The weight percent of each of the two groups in a molecule or mixture predicts the behavior of a particular molecular structure.

In an even more advantageous embodiment, said dendrimer used with said catalyst, defined above, corresponds to the following general formula (II):

A- [CL] ₁ -B] ₃ (H)

in which :

A represents a hydrophobic core of general formula III:

in which (X) m represents:

where m is an integer equal to 1, 2 or 3, and k is an integer equal to 0, 1 or 2 and when m

= 1, then k = 2; when m = 2, k = 1 and when m = 3, k = 0, n is an integer equal to 1, 2, 3, 4 or 5 carbon atoms, the mesitylene being connected to the alkyl chain comprising the integer n ,

L represents a spacer, of general formula (IV)

in which (X) m 'represents

where m 'is an integer equal to 1, 2 or 3, and k is an integer equal to 0, 1 or 2 and when m = 1, then k = 2; when m = 2, k = 1 and when m = 3, k = 0,

is an integer equal to 1, 2, 3, 4 or 5 carbon atoms, the oxygen of the general formula

(IV) being bound to (X) m,

P = I to 10, especially 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and, in particular 1 or 2, i = 0 or 1 - B represents: a group comprising a triazole connected to a dendron comprising a ring, in particular aromatic ring, on which are grafted amphiphilic molecules, preferably located at the end of said dendron, which amphiphilic molecules consist in particular of PEG.

(X) ^m and (X) m 'thus make it possible to vary both the length of the dendrimer chains, as well as the number of chains present on the dendrimer.

The spacer may or may not be present, and when present can limit steric hindrance.

The triazole present in part B is connected to the group (X) moi or (X) m and makes it possible to connect the dendron to the hydrophobic core.

The term "dendron" refers to the terminal part of the branches of the dendrimer. The dendron has a ring connected to the triazole to support the amphiphilic molecules.

Said ring may be any type of ring, for example cycloalkyl comprising several carbon atoms, for example from 5 to 8 carbon atoms, it may also be an aromatic ring, for example a benzene ring or a heterocycle, for example a pyridine ring, these examples are not limiting.

In an even more advantageous embodiment, said amphiphilic molecules of said dendrimer used with said catalyst, defined above, consist of 9 to 243 PEG, preferably 27 to 81.

By "PEG" is meant a polyethylene glycol group of the formula W:, where q is an integer from 1 to

10, in particular 3.

A hydrophobic core having three groups (X) m, without spacer (i = 0), therefore comprises at most 9 chains.

The addition of a spacer (i = 1 and p = 1) on each branch of the heart then leads to an 87-branched dendrimer.

The addition of two spacers (p = 2) then leads to a dendrimer with 243 branches.

In an even more advantageous embodiment, the number of dendrons of said dendrimer used with said catalyst, defined above, is from 9 to 27 and the number of PEG by dendron is 1, 2 or 3, in particular 3, said dendrons with a chain:

Y: or Z:

n being 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, in particular n = 5, extending between said ring of said dendron and said triazole.

Y is a short string and Z is a long string.

As a result, the length of the chain between the triazole and the dendron cycle is variable and makes it possible to obtain dendrimers with different bulkings.

The number of PEGs per dendron as well as the number of dendrons per dendrimer and the number of spacers therefore makes it possible to vary both the molecular weight and the HLB.

Table IV below summarizes the different dendrimers used as well as their formula, their molecular weight and their HLB: (the notation DxxPEG means a dendrimer comprising xx chains made of PEG)

TABLE IV

In an even more advantageous embodiment, said dendrimer used with said catalyst, defined above, is chosen from the following molecules:

- PEG Y chain dendrimer 27: C3 ₄₂ H597O ₁₁ 7N ₂₇ SIg



In an even more advantageous embodiment, the metathesis reaction carried out with said dendrimer used with said catalyst, defined above, is a cyclic olefin ROMP.

In an even more advantageous embodiment, the metathesis reaction carried out with said dendrimer used with said catalyst, defined above, is a DCM of dienes.

In an even more advantageous embodiment, the metathesis reaction carried out with said dendrimer used with said catalyst, defined above, is an enynes RCM. In an even more advantageous embodiment, the metathesis reaction carried out with said dendrimer used with said catalyst, defined above, a CM of olefins.

In another aspect, the present invention relates to a dendrimer of the following general formula (I):

A - [(L) _r B] _x (I) in which A corresponds to a hydrophobic core, L corresponds to an optionally present spacer, and B corresponds to an amphiphilic part comprising a dendron consisting of amphiphilic terminations, x corresponds to a number integer ranging from 2 to 6, i corresponds to an integer from 0 to 1, and said dendrimer having a molecular weight of from 5000 to 90000, preferably from 7212 to 76509, more preferably from 8787 to 28153, still more preferably from 8787 to 23349 and a hydrophilic-lipophilic balance (HLB) of from 14 to 20, in particular from 15.59 to 17.41, excluding the following dendrimers:

- 27 PEG dendrimer long chain: C4i4H ₇ 4iOi53N27Si9 11

It should be noted that the dendrimers of the invention do not contain ruthenium atoms. In an advantageous embodiment, the dendrimer defined above has the following general formula (II):

A- [CL] ₁ -B] ₃ (H)

in which : A represents a hydrophobic core of general formula III:

in which (X) m represents:

L represents a spacer, of general formula (IV)

in which (X) m 'represents

(IV) being bound to (X) m,

P = 1 to 10, especially 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and in particular 1 or 2, i = 0 or 1 B represents: a group comprising a triazole connected to a dendron comprising a ring, in particular an aromatic ring, on which are grafted amphiphilic molecules, preferably located at the end of said dendron, which amphiphilic molecules consist in particular of PEG, said dendrimer having a molecular weight of from 5000 to

90000, preferably from 7212 to 76509, more preferably from 8787 to 28153, still more preferably from 8787 to 23349 and a hydrophilic-lipophilic balance (HLB) of from 14 to 20, especially from 15.59 to 17.41.

In an advantageous embodiment, said amphiphilic molecules of the dendrimer defined above, consist of 9 to 243 PEG, preferably 27 to 81.

By "PEG" is meant a polyethylene glycol group of the formula

W: _> where q is an integer from 1 to

10, in particular 3.

In an advantageous embodiment, the number of dendrums of the dendrimer defined above is from 9 to 27 and the number of PEG by dendron is 1, 2 or 3, in particular 3, said dendrons comprising a chain:

Y:

, or Z:

n being 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, in particular n = 5 the present invention relates to the use of at least one water-soluble amphiphilic dendrimer and at least one ruthenium catalyst, for the implementation of metathesis reactions of olefins or enynes, in aqueous medium, without organic solvent. between said cycle of said dendron and the imidazole of said dendrimer, the link to the cycle of said dendron taking place on the right side of said dendrimer.

In an advantageous embodiment, the dendrimer defined above is chosen from the following molecules:

- short chain PEG dendrimer 27: C342H597O117N ₂₇ SIg

According to another aspect, the invention relates to a process for carrying out metathesis reactions of olefins or enynes comprising a step of contacting a dendrimer, as defined above, with a catalyst. ruthenium with an initial olefin or an initial enyne, in aqueous medium, without organic solvent, to form a final olefin, said catalyst and said dendrimer being optionally recovered after formation of the final olefin.

The term "initial olefin" or "initial enyne" (also referred to as substrate) refers to the olefin or enyne which is subject to metathesis and which are as defined above.

In an advantageous embodiment, the proportion of dendrimer in the process defined above is from about 0.01 mol% to about 0.03 mol%, preferably from about 0.015 mol% to about 0.025 mol%. mole, in particular about 0.02 mol%.

In an advantageous embodiment, the ruthenium catalyst of the process defined above is insoluble in water.

In an advantageous embodiment, the olefins or enynes used in the process defined above are insoluble in water.

In an advantageous embodiment, said metathesis reactions are carried out under an inert gas.

In an advantageous embodiment, wherein said metathesis reactions are carried out under an atmosphere consisting of air. In an advantageous embodiment, the temperature range of the above process is from about 20 ^° C. to about 65 ° C., preferentially from about 40 ^° C. to about 60 ^° C., in particular about 20 ^° C. at about 40 ^° C., in particular from about 20 ^° C. to about 25 ° C.

In an advantageous embodiment, the metathesis reaction carried out with the method defined above is a RCM. In an advantageous embodiment, the method defined above comprises the following steps: a. contacting a dendrimer as defined above with a ruthenium catalyst in an amount of from about 0.04 mol% to about 0.2 mol%, in particular about 0.1 mol%. mole, with an initial olefin selected from among the dienes, contained in a container not in contact with the air, b. adding a quantity of degassed water to the above container to obtain an olefin, catalyst and dendrimer mixture in the water, and c. agitating the aforesaid mixture in water, under a nitrogen atmosphere at room temperature for a time necessary for the cyclization and complete disappearance of said diene.

This is a DCM of diene under inert atmosphere.

This process therefore describes a ring closure metathesis reaction and can be carried out with any type of olefin having two terminal or non-terminal double (diene) double bonds.

The addition of degassed water is necessary for the catalyst to be protected from the air liable to degrade it.

The quantity of water added is that corresponding to a final concentration of the medium of 0.01 M to 1 M, in particular from 0.05M to 0.5M, in particular 0.1M.

The reaction is carried out at between 20 ^° C. and 40 ^° C., in particular at 25 ° C.

The stirring of the mixture must be strong to create micelles constituted of the various constituents of the medium. In particular, the agitation will make it possible to obtain contact between soluble and insoluble molecules in the water so as to carry out the reaction.

The agitation time of the mixture in water is a function of the diene used and is from 1h to 48h, in particular from 12 to 24h, in particular 24h.

It has been shown in the case of diene 3 that the yield is quantitative as early as 3 hours of stirring.

Under these conditions, the amount of catalyst that can be used is as low as 0.06% without increasing the stirring time.

It has been shown that at 0.04%, the reaction requires a longer stirring time, in particular 48h. In an advantageous embodiment, the initial olefin of the process defined above is chosen from 1,7-octadiene, N, N-diallyl-4-methylbenzenesulfonamide, diallyl diethyl malonate and N, N-diallylbenzamide. and the catalyst is the Grubbs 2 catalyst, especially in an amount of 0.06% to obtain respectively cyclohexene, N- (p-toluenesulfonyl) -3-pyrroline, diethylcyclopent-3-ene-1, 1-dicarboxylate, and N-benzoyl-3-pyrroline. In an advantageous embodiment, the method defined above comprises the following steps: at. contacting a dendrimer, as defined above, with a ruthenium catalyst in an amount of from about 0.1 mol% to about 0.3 mol%, preferably about 0.15 mol. mole% to about 0.25 mole%, especially about 0.2 mole%, with an olefin selected from dienes, contained in a container in contact with air, b. adding a quantity of non-degassed water to the above container to obtain an initial olefin mixture, catalyst and dendrimer in water, and c. agitating the aforesaid mixture in water, in an atmosphere consisting of air at room temperature for a time necessary for the cyclization and complete disappearance of said diene.

This is an air-cooled diene RCM consisting of air.

The addition of degassed water is no longer necessary since the reaction is carried out in air. However, the amount of catalyst must be increased and must therefore be 0.2% to obtain an almost quantitative yield. The amount used remains nevertheless 10 times lower than that used in the processes of the prior art.

It has also been shown that a catalyst amount of 0.04% leads to a yield reduction (40%). The other parameters are identical to what has been said about the reaction of

RCM of diene under inert atmosphere.

In an advantageous embodiment, the initial olefin of the process defined above is diallyl diethyl malonate and the catalyst is the Grubbs 2 catalyst, in particular in an amount of 0.2% to obtain diethylcyclopent-3-ene. -l, l-dicarboxylic acid. In an advantageous embodiment, the method defined above comprises the following steps: a. contacting a dendrimer, as defined above, with a catalyst in an amount of from about 1 mol% to about 3 mol%, preferably from about 1.5 mol% to about 2 mol%. 5 mol%, in particular about 2 mol%, with an initial enyne contained in a container not in contact with the air, b. adding a quantity of degassed water to the above container to obtain an initial enyne mixture, catalyst and dendrimer in water, and c. stirring said mixture in water, under a nitrogen atmosphere at room temperature for a time necessary for the cyclization and disappearance of said initial enyne.

It is a RCM of enyne under inert atmosphere.

This method therefore describes a ring closure metathesis reaction and can be implemented with any type of enyne. The parameters are identical to those corresponding to the RCM of diene under inert atmosphere.

Under these conditions, the amount of catalyst that can be used is as low as 2% without increasing the stirring time.

In an advantageous embodiment, wherein the enyne is 2- (allyloxy) but-3-yn-2-yl) benzene or 1- (allyloxy) prop-2-yn-1, 1-diyl) dibenzene and the catalyst is the Grubbs 2 catalyst, in particular in an amount of 2%, to obtain 2-methyl-2-phenyl-3-vinyl-2,5-dihydrofuran and 2,2-diphenyl-3-vinyl-2, respectively. , 5-dihydrofuran.

In an advantageous embodiment, the method defined above comprises the following steps: a. contacting a dendrimer, as defined above, with a catalyst in an amount of from about 1 mol% to about 3 mol%, preferably from about 2 mol% to about 3 mol% in mol, in particular about 2 mol%, with an initial enyne contained in a container in contact with the air, b. adding a quantity of non-degassed water to the above container to obtain an initial enyne mixture, catalyst and dendrimer in water, and c. agitating said mixture in water, in an atmosphere consisting of air at room temperature for a time necessary for the cyclization and disappearance of said initial enyne.

It is a RCM of enyne in an atmosphere consisting of air. This method therefore describes a ring closure metathesis reaction and can be implemented with any type of enyne.

The addition of degassed water is no longer necessary since the reaction is carried out in air. However, the amount of catalyst must be increased to 3%. The other parameters are identical to those corresponding to the RCM of diene under inert atmosphere.

In an advantageous embodiment, the metathesis reaction carried out with the method defined above is a ROMP.

In an advantageous embodiment, the method defined above comprises the following steps: a. contacting a dendrimer, as defined above, with a catalyst in an amount of from about 0.04 mol% to about 0.2 mol%, in particular about 0.1 mol% with an initial olefin selected from cyclic olefins contained in a non-air contacting container, b. adding a quantity of degassed water to the above container to obtain an initial olefin mixture, catalyst and dendrimer in water, and c. agitating said mixture in water under a nitrogen atmosphere at room temperature for a time necessary for opening and complete disappearance of said cyclic olefin. It is a cyclic olefin ROMP under an inert atmosphere.

This process therefore describes a ring opening metathesis reaction and can be carried out with any type of cyclic olefin.

The parameters are identical to the RCM of diene under inert atmosphere. Under these conditions, the amount of catalyst that can be used is as low as 0.06% without increasing the stirring time.

In an advantageous embodiment, the method defined above comprises the following steps: a. contacting a dendrimer, as defined above, with a catalyst in an amount of from about 0.1 mol% to about 0.3 mol%, preferably about 0.15 mol%. mole at about 0.25 mole%, especially about 0.2 mol%, with an initial olefin selected from cyclic olefins contained in a container in contact with air, b. adding a quantity of non-degassed water to the above container to obtain an initial olefin mixture, catalyst and dendrimer in water, and c. agitating the aforesaid mixture in water under an atmosphere consisting of air at room temperature for a time necessary for opening and the complete disappearance of said cyclic olefin.

It is a cyclic olefin ROMP in an atmosphere consisting of air. This process therefore describes a ring opening metathesis reaction and can be carried out with any type of cyclic olefin.

The addition of degassed water is no longer necessary since the reaction is carried out in air. However, the amount of catalyst must be increased to 0.2% in order to have an almost quantitative yield. The amount used, however, remains 10 times lower than that used in the processes of the prior art. The other parameters are identical to those corresponding to the RCM of diene under inert atmosphere.

In an advantageous embodiment, the metathesis reaction carried out with the method defined above is a CM.

In an advantageous embodiment, the method defined above comprises the following steps: a. contacting a dendrimer, as defined above, with a catalyst in an amount of from about 1 mol% to about 5 mol%, preferably from about 3 mol% to about 5 mol%. mole, in particular about 2 mol%, with a mixture of two identical initial olefins, in particular allyl alcohol or 9-decenoic acid, or different, in particular 9-decen-1-ol and the acrylate of methyl, or 4-vinyl-cyclohexene 1,2-epoxide and butyl acrylate, contained in a non-airborne container, b. adding a quantity of degassed water to the above container to obtain an initial olefin mixture, catalyst and dendrimer in water, and c. stirring of the above mixture in water, under a nitrogen atmosphere at about 60 ⁰ C for a time necessary for the formation of the final olefin. It is a CM of olefins under an inert atmosphere.

This method therefore describes a cross-metathesis reaction and can be implemented with all types of identical or different olefins having a terminal double bond or not. The parameters are identical to those corresponding to the RCM of diene under an inert atmosphere except the temperature of the reaction which is carried out between 40 ^° C. and 60 ^° C., in particular at 40 ^° C.

Under these conditions, the amount of catalyst that can be used is as low as 2% without increasing the stirring time. In an advantageous embodiment, the two olefins used in the process defined above are 9-decen-1-ol and methyl acrylate and the catalyst is the Grubbs 2 catalyst, in particular in an amount of 2% by weight. obtain the methyl 1-hydroxy-2-undecenoate.

In an advantageous embodiment, the method defined above comprises the following steps: a. contacting a dendrimer, as defined above, with a catalyst in an amount of from about 3 mol% to about 5 mol%, preferably from about 4 mol% to about 5 mol%. mole, in particular about 5 mol%, with a mixture of two identical initial olefins, in particular allyl alcohol or 9-decenoic acid, or different, in particular 9-decen-1-ol and the acrylate of methyl, or 4-vinyl-cyclohexene 1,2-epoxide and butyl acrylate, contained in a container in contact with air, b. adding a quantity of non-degassed water to the above container to obtain a mixture of initial olefins, catalyst and dendrimer in water, and c. stirring of the above mixture in water under an atmosphere consisting of air at about 60 ^° C. for a time necessary for the formation of the final olefin.

It is a CM of olefins in an atmosphere consisting of air.

This method therefore describes a cross-metathesis reaction and can be implemented with all types of identical or different olefins having a terminal double bond or not.

The addition of degassed water is no longer necessary since the reaction is carried out in air. However, the amount of catalyst must be increased to 5% to obtain an almost quantitative yield. The parameters are identical to those corresponding to the RCM of diene under inert atmosphere, except the temperature of the reaction which is carried out between 40 ^° C. and 65 ° C., in particular

EXPERIMENTAL PART

The examples below are given purely by way of illustration and in no way limit the invention to these.

Example 1 Preparation of the Polyethylene Glycol (PEG) Dendrimers a) Synthesis of the Hydrophobic Core

The synthesis of the dendritic hydrophobic core is carried out according to Scheme 1. It begins with the nonaallylation of mesitylene induced by the graft CpFe ⁺ in the ambient air in the presence of KOH and allyl bromide (Moulins, F., Djakovitch, L. Boese, R., Gloaguen, B., Thiel, W., Fillaut, J.-L., Delville M.-H., Astruc, D. Angew, Int.Ed. Ed, Engl, 1993, 32, 1075-1077, Sartor, V., Jakovitch, L. Fillaut, J.-L, Moulines, F. Neveu, F., Marvaud, V. Guittard, J., Bias, J.-C .; JA Am Chem Soc 1999, 121, 2929-2930, followed by photolysis by visible light in MeCN in the presence of PPh _{3 in} order to remove the CpFe group, the product then undergoes hydrosilylation with HSiMe ₂ CH ₂ Cl. and Karsted's catalyst (Sartor, V., Djakovich, L., Fillaut, J.-L .; Moulines, F. Neveu, F., Marvaud, V. Guittard, J., Biais, J.-C .; Astruc, DJ Am Chem Soc 1999, 121, 2929-2930. Finally, the reaction with NaN ₃ leads to the non-azide dendritic core (C. Ornelas, J. Ruiz Ara nzaes, E. Cloutet, S. Alves, D. Astruc Angew. Chem. Int. Ed., 2007, 46 (1) 872-877; E. Boisselier, AK Diallo, L. Salmon, J. Ruiz, D. Astruc Chem. Commun., 2008, DOI: 10.1039 / <B808987F>)

Diagram 1

b) Synthesis of the short-chain dendron (Y) (scheme 2):

The tris-triethylene glycol dendron (1.840 g, 2.80 mmol) and the propargyl alcohol (314 mg, 5.60 mmol, 2 eq.) Are introduced into a Schlenck, and distilled THF (100 mL) is added. NaH (202 mg, 8.40 mmol, 3 eq.) Is also added to the solution. The mixture is agitated for 12 hours at 45 ° C. At the end of the reaction, water is added and excess THF and propargyl alcohol are evaporated under vacuum. 1.6 g of a yellow oil is obtained (91% yield).

¹ H NMR (CDCl _3, 250MHz): 6.58 (2H, CH-arom extern.), 4.49 (2Η, O-CH ₂ -arom extern.), 4.15 (8Η, O-CH ₂ CH ₂ O- and -propargyl extern arom), 3.65 (30Η, OCH ₂ CH ₂ O), 3.37 (9Η, CH ₃ O), 2.47 (1Η, C-CHalkyne).

¹³ C NMR (CDCl ₃ , 62 MHz): 153.00 (aromatic Cq-O), 138.39 (Cq-CH ₂ arom.), 133.09 (Cq-O arom.

CH2-O), 107.92 (arom. CH), 79.93 (Alq. Cl), 75.14 (CH alkyne), 70.86 (O-CH ₂ ),

59.36 (O-CH ₃ ), 57.36 (CH ₂ -alkyl).

Infrared _and ikyn _e : 2094 cm ^-1

Elemental analysis: Anal. Cale, for C ₃ iH ₅₂ Oi ₃ : C 58.85 H 8.28, found: C 58.72

H 8.67.

Figure 2

c) Synthesis of the Long Chain (Z) dendron (Scheme 3):

The tris-triethylene glycol dendron (1 g, 1.57 mmol) and the tetraethylene glycol (2.95 g, 15.7 mmol) are introduced into a Schlenck, and distilled THF (50 mL) is added. NaH (108 mg, 2.7 mmol) is also added to the solution. The mixture is stirred for 12 hours at 50 ^° C.

At the end of the reaction, water is added and the THF is evaporated. The product is extracted with CH ₂ Cl ₂ and purified by chromatography (MeOH). Ig of a yellow oil is obtained (83% yield).

Tris-triethylene glycol tetraethylene glycol dendron (600 mg, 0.65 mmol) and distilled THF (50 mL) are introduced into a Schlenck, and NaH (47 mg, 1.95 mmol) is added at 0 ^° C. The propargyl bromide ( 155 mg, 1.3 mmol) is then added to the solution. The mixture is stirred for 2 hours at 0 ^° C. and then for 2 hours at 25 ° C. At the end of the reaction, water is added, then excess THF and propargyl bromide are evaporated under vacuum. 600 mg of a yellow oil is obtained (95% yield).

¹ H NMR (CDCl _3, 250MHz): 6.39 (2H, CH-arom extern.), 4.26 (2Η, O-CH ₂ -arom extern.), 3.98 (4Η, CH ₂ O-extern arom and CH ₂ -. alkyne), 3.46 (30Η, OCH ₂ CH ₂ O), 3.17 (9Η, CH ₃ O), 2.36 (1Η, C-CH alkyne)

¹³ C NMR (CDCl _3, 62 MHz): 152.41 (Cq-O arom.), 137.50 (Cq-CH ₂ arom.), 133.63 (CQ-CH2-O), 106.87 (CH arom.), 79.54 (Cq alkyne ), 74.75 (CH alkyne), 70.46 (O-CH ₂ ), 58.74 (O-CH ₃ ), 58.13 (CH ₂ -alkyne) Infrared _at ikyn _e : 2100 cm ^-1 Mass spectrum Maldi TOF: Cale, for C ₃₉ H ₆₈ O _n : 808, found: 831 (MNa ⁺ ).

diagram 3

d) Synthesis of the 27-chain dendrimer (short-chain dendron Y) 17 and synthesis of the 27-chain dendrimer (long-chain dendron Z) 18 by "click chemistry"

In both cases, the chemistry "click" synthesis follows the same protocol below.

The nonaazide dendrimer (1 eq) and the alkyne dendron (1.5 eq per branch) are dissolved in THF. At 0 ^° C., the addition of CuSO 4 is carried out (2 eq per branch, IM in aqueous solution), followed by the addition of a freshly prepared solution of sodium ascorbate dropwise (4 eq per branch). , IM in aqueous solution) in order to have a THF / water mixture: 1 / 1. The solution is stirred for 12 hours at 25 ° C. under a nitrogen atmosphere. After evaporating the THF under vacuum, dichloromethane and aqueous ammonia solution are added. The mixture was stirred again for 10 minutes to remove all Cu encapsulated in the dendrimer as [Cu (NH ₃ ) ₆ ] ²⁺ . The organic phase is washed twice with water, dried over sulphate of sodium then all the solvent is evaporated under vacuum. The product is precipitated with a MeOH / ether mixture in order to remove the excess dendron.

* Characterizations of the dendrimer functionalized with PEG short dendron 17: 1H NMR (CDCl ₃ , 250MHz): 7.44 (9H, CH-triazole), 6.92 (36Η, CH-internal arom), 6.54 (18Η, CH-arom extern ), 4.57 (18Η, triazole-CH ₂ -0), 4.41 (18Η, O-CH ₂ -arom extern), 4.09 (72Η, CH ₂ O-arom, extern and Si-CH ₂ -triazole), 3.61 ( 270Η, OCH ₂ CH ₂ O), 3.33 (27Η, CH ₃ O), 1.59 (18Η, CH ₂ CH ₂ CH ₂ Si), 1.06 (18H, CH ₂ CH ₂ CH ₂ Si), 0.60 (18H, CH _2). CH ₂ CH ₂ Si), 0.008 (54Η,

If (CHs) ₂ ). 1 ³ C NMR (CDCl _3, 62 MHz): 152.49 (. CH, extern arom), 144.48 (C _q of triazole), 137.67 (. Cq, arom core), 132.28 (. Cq, arom extern), 123.52 (CH of triazole and arom. core), 107.16 (C 0 CH ₂ O), 70.39 (OCH ₂ CH ₂ O), 63.53 (triazole-CH ₂ -O), 58.91 (CH ₃ O), 53.38 (OCH 2 -bromine), 43.77 (CH ₂ CH ₂ CH ₂ Si), 42.7 (SiCH ₂ -triazole), 40.93 (C 9 -bromine intern), 17.58 (CH ₂ CH ₂ CH ₂ Si), 15.18 (CH ₂ CH ₂ CH ₂ Si), -3.91 (Si (CH ₃ ) ₂ ). IR: disappearance of the azide and alkyne bands. SEC: Atention time: 1348 seconds.

Elemental analysis: Anal. Calc'd for C H ₇₃ O ₅₃ N ₂₇ SJ: C 56.95, H 8.34; found: C, 56.37, H 8.33.

* Characterizations of the dendrimer functionalized with the long PEG 18 dendron: (See: E. Boisselier, A. Diallo K., L. Salmon, J. Ruiz, D. Astruc, Common Chem., 2008, DOI: 10.1039 / <B808987F>)

¹ H NMR (CDCl _3, 250MHz): 7.45 (9H, CH-triazole), 6.93 (36Η, CH-arom intern.), 6.56 (18Η, CH-arom extern.), 4.62 (18Η, triazole-CH ₂ - 0), 4.43 (18Η, O-CH ₂ -arom extern), 4.11 (72Η, CH ₂ O-arom, extern and Si-CH ₂ -triazole), 3.64 (414Η, OCH ₂ CH ₂ O), 3.37 ( 27Η, CH ₃ O), 1.59 (18Η, CH ₂ CH ₂ CH ₂ Si), 1.07 (18H, CH ₂ CH ₂ CH ₂ Si), 0.60 (18H, CH ₂ CH ₂ CH ₂ Si), 0.006 (54Η, If (CH ₃ ) ₂ ).

¹³ C NMR (CDCl _3, 62 MHz): 151.62 (CH, extern arom.), 144.48 (C _q of triazole), 136.83 (Cq, arom core.), 132.75 (Cq, arom extern.), 123.52 (CH of triazole and arom. core), 106.23 (CqCH ₂ O), 69.54 (OCH ₂ CH ₂ O), 63.53 (triazole-CH ₂ -O), 58.00 (CH ₃ O), 53.38 (OCH 2 -bromine), 43.77 (CH ₂ CH ₂ CH ₂ Si), 42.7 (SiCH ₂ -triazole), 40.93 (C 9 -bromine intern), 17.82 (CH ₂ CH ₂ CH ₂ Si), 14.90 (CH ₂ CH ₂ CH ₂ Si), - 4.84 (Si (CH ₃ ) ₂ ). DOSY: D = 1.16 (± 0.1) x 10 ^{~ 10} m7s; Rh = 4.9 (± 0.1) nm

(D: diffusion coefficient, Rh: hydrodynamic radius)

IR: disappearance of the azide and alkyne bands. SEC: retention time: 1256 seconds.

Mass spectrum MALDI-TOF spectrum: Calcd for C ₄ H ₇₄ I ₄ N IOI ₅₃ ₂₇ Si _9: 8798; found: 8824 (MNa ⁺ ). Elemental analysis: Anal. Cale, for C ₄ I ₄ H ₇₄ IO 1 ₅₃ N ₂₇ Si ₉ : C 56.52, H 8.49; found: C, 56.31, H 8.49.

Light scattering: Rh = 4.5 (± 0.4) nm.

e) Synthesis of the 81-chain dendrimer (short-chain dendron Y) 19 and synthesis of the 81-chain dendrimer (long-chain dendron Z)

In both cases, the chemistry "click" synthesis follows the same protocol below. The 27-azide dendrimer (1 eq.) And the alkyne dendron (1.5 eq per branch) are dissolved in THF. At 0 ^° C., the addition of CuSO ₄ is carried out (2 equivalents per branch, IM in aqueous solution), followed by the addition of a freshly prepared solution of sodium ascorbate dropwise (4 equivalents per branch, IM in aqueous solution) to obtain a THF / water mixture: 1 / 1. The solution is stirred for 24 hours at 25 ° C. under a nitrogen atmosphere. After evaporating the THF under vacuum, dichloromethane and aqueous ammonia solution are added. The mixture is stirred again for 10 minutes to remove all Cu ¹¹ encapsulated in the dendrimer in the form [Cu (NH ₃ ) ₆ ] ⁺ . The organic phase is washed twice with water, dried over sodium sulfate, then all the solvent is evaporated under vacuum. The product is precipitated with a MeOH / ether mixture in order to remove the excess dendron.

* Characterizations of the dendrimer functionalized with PEG short dendron 19:

¹ H NMR (CDCl _3, 250MHz): 7.44 (CH-triazole), 7.11 and 6.85 (CH-arom intern.), 6.57, 4.60 (triazo Ie-CH ₂ -O), 4.45 ((CH-arom extern.) O-CH ₂ -arom extern), 4.11 (CH ₂ O-arom, extern and Si-CH ₂ -triazole), 3.63 (OCH ₂ CH ₂ O), 3.35 (CH ₃ O), 1.59 (CH ₂ CH ₂ CH ₂ Si), 1.10 (CH ₂ CH ₂ CH ₂ Si), 0.59 (CH ₂ CH ₂ CH ₂ Si), 0.0 3 (Si (CH ₃ ) ₂ ). ¹³ C NMR (CDCl _3, 62 MHz): 151.61 (CH, extern arom.), 144.48 (C _q of triazole), 132.74 (Cq, arom core.), 132.28 (Cq, arom extern.), 123.52 (CH of triazole and arom.core), 106.22 (CqCH ₂ O), 70.93 (OCH ₂ CH ₂ O), 63.53 (triazole-CH ₂ -O), 58.00 (CH ₃ O), 53.38 (OCH 2-aromener), 43.77 (CH ₂ CH ₂ CH ₂ Si), 42.7 (SiCH ₂ -triazole), 40.93 (C 1-4 arom), 17.58 (CH ₂ CH ₂ CH ₂ Si), 15.18 (CH ₂ CH ₂ CH ₂ Si), - 3.91 (Si (CH ₃ ) ₂ ). IR: disappearance of the azide and alkyne bands. SEC: retention time: 1281.6 seconds.

* Characterizations of the dendrimer functionalized with the long PEG dendron 20: (See: E. Boisselier, A. K. Diallo, L. Salmon, J. Ruiz, D. Astruc, Common Chem., 2008, DOI: 10.1039 / <B808987F>)

¹ H NMR (CDCl _3, 250MHz): 7.41 (27H, CH-triazole), 6.97 (144Η, CH-arom intern.), 6.56 (54Η, CH-arom extern.), 4.62 (54Η, triazole-CH ₂ - 0), 4.43 (54Η, O-CH ₂ -arom extern), 4.13 (126Η, CH ₂ O-arom, extern and Si-CH ₂ -triazole), 3.64 (1242Η, OCH ₂ CH ₂ O), 3.37 ( 81Η, CH ₃ O), 1.59 (54Η, CH ₂ CH ₂ CH ₂ Si), 1.09 (54H, CH ₂ CH ₂ CH ₂ Si), 0.57 (54H, CH ₂ CH ₂ CH ₂ Si), 0.06 (216Η,

If (CH ₃ ),)

¹³ NMR (CDCl ₃ , 62 MHz): 152.60 (CH, extern arom.), 144.48 (C _q of triazole), 137.79 (Cq, core arom), 133.75 (Cq, external arom), 123.52 (CH of triazole and arom.core), 107.23

(CqCH ₂ O), 70.66 (OCH ₂ CH ₂ O), 63.53 (triazole-CH ₂ -O), 58.99 (CH ₃ O), 53.38 (OCH 2 -bromine), 43.77 (CH ₂ CH ₂ CH ₂ Si). ), 42.7 (SiCH ₂ -triazole), 40.93 (Cq-arom.intern), 17.82

(CH ₂ CH ₂ CH ₂ Si), 14.90 (CH ₂ CH ₂ CH ₂ Si), -4.84 (Si (CH ₃ ) ₂ )

IR: disappearance of the azide and alkyne bands.

SEC: retention time: 1170 seconds.

DOSY: D = 5.94 (± 0.1) x ^10-11 m 7s, Rh = 9.7 (± 0.7) nm (D: diffusion coefficient, Rh: hydrodynamic radius)

Light scattering: Rh = 9.1 (± 0.6) nm.

f) Synthesis of the dendrimer with 243 chains (short-chain dendron Y) 21 and Synthesis of the dendrimer with 243 chains (long-chain dendron Z) 22 In both cases, the synthesis by "click" chemistry proceeds according to the same protocol - after. The 81-azide dendrimer (1 eq) and the alkyne dendron (1.5 eq per branch) are dissolved in THF. At 0 ^° C., the addition of CuSO 4 is carried out (2 eq per branch, IM in aqueous solution), followed by the addition of a freshly prepared solution of sodium ascorbate dropwise (4 eq per branch). , IM in aqueous solution) in order to have a THF / water mixture: 1 / 1. The solution is stirred for 12 hours at 25 ° C. under a nitrogen atmosphere. After evaporating the THF under vacuum, dichloromethane and aqueous ammonia solution are added. The mixture is stirred again for 10 minutes to remove all Cu ¹¹ encapsulated in the dendrimer in the form [Cu (NH ₃ ) e] ²⁺ . The organic phase is washed twice with water, dried over sodium sulfate and all the solvent is evaporated under vacuum. The product is precipitated with a MeOH / ether mixture in order to remove the excess dendron.

* Characterizations of the dendrimer functionalized with the short PEG dendron 21:

¹ H NMR (CDCl _3, 250MHz): 7.44 (CH-triazole), 7.13 and 6.87 (CH-arom intern.), 6.56, 4.59 (triazo Ie-CH ₂ -O), 4.44 ((CH-arom extern.) O-CH ₂ -arom extern), 4.11 (CH ₂ O-arom, extern and Si-CH ₂ -triazole), 3.63 (OCH ₂ CH ₂ O), 3.34 (CH ₃ O), 1.56 (CH ₂ CH ₂ CH ₂ Si), 1.09 (CH ₂ CH ₂ CH ₂ Si), 0.58

(CH ₂ CH ₂ CH ₂ Si), 0.05 (Si (CH ₂ ) ₂ ).

¹³ C NMR (CDCl _3, 62 MHz): 152.49 (CH, extern arom.), 144.48 (Q of triazole), 137.67 (Cq, arom core.), 132.28 (Cq, arom extern.), 123.52 (CH of triazole and arom.core), 107.16

(CqCH ₂ O), 70.55 (OCH ₂ CH ₂ O), 63.53 (triazole-CH ₂ -O), 58.95 (CH ₃ O), 53.38 (OCH 2 -bromine), 43.77 (CH ₂ CH ₂ CH ₂ Si). ), 42.7 (SiCH ₂ -triazole), 40.93 (internal Cq-arom), 17.58

(CH ₂ CH ₂ CH ₂ Si), 15.18 (CH ₂ CH ₂ CH ₂ Si), -3.91 (Si (CH ₃ ) ₂ ).

IR: disappearance of the azide and alkyne bands.

* Characterizations of the dendrimer functionalized with the long PEG dendron 22: (See: E. Boisselier, A. K. Diallo, L. Salmon, J. Ruiz, D. Astruc, Common Chem., 2008, DOI: 10.1039 / <B808987F>)

¹ H NMR (CDCl _3, 250MHz): 7.41 (81H, CH-triazole), 7.09 (117Η, CH-arom intern.), 6.56 (234Η, CH-arom extern.), 4.61 (162Η, triazole-CH ₂ - 0), 4.44 (234Η, O-CH ₂ -aryng extern), 4.11 (396Η, CH ₂ O-arom, extern and Si-CH ₂ -triazole), 3.64 (3726Η, OCH ₂ CH ₂ O), 3.37 ( 243Η, CH ₃ O), 1.59 (234Η, CH ₂ CH ₂ CH ₂ Si), 1.09 (234H, CH ₂ CH ₂ CH ₂ Si), 0.54 (234H, CH ₂ CH ₂ CH ₂ Si), 0.06 (702Η,

If (CH ₃ ),) C NMR (CDCl ₃ , 62 MHz): 151.60 (CH, extern arom.), 144.48 (Q of triazole), 136.80 (Cq, core arom), 132.78 (Cq, external arom), 123.52 (CH of triazole) and arom. core), 106.23 (CqCH ₂ O), 68.73 (OCH ₂ CH ₂ O), 63.53 (triazole-CH ₂ -O), 57.39 (CH ₃ O), 53.38 (OCH 2 -bromine), 43.77 ( CH ₂ CH ₂ CH ₂ Si), 42.7 (SiCH ₂ -triazole), 40.93 (C 1-4 arom), 17.82 (CH ₂ CH ₂ CH ₂ Si), 14.90 (CH ₂ CH ₂ CH ₂ Si), -4.84 (Si (CH ₃ ) ₂ ) (see spectrum on page 23) IR: disappearance of the azide and alkyne bands. SEC: retention time: 1111 seconds. Light scattering: Rh = 10 (± 1) nm.

Example 2 Preparation of N, N-diallylbenzamide 4 (Scheme 4)

Benzoyl chloride (1 equiv) is added to a solution of diallyl amine (2 equiv), triethyl amine (5 equiv) and in dichloromethane (0.5 M). The reaction mixture is stirred at ambient temperature for 20 minutes and then diluted with dichloromethane. This solution is washed with 1N HCl and then dried over Na ₂ SO 4. After evaporation of the dichloromethane, the product obtained is purified by chromatography on silica gel using EtOAc / hexane 1/1 as eluent. 4 yellow yellow oil is obtained. The yield of the reaction is 94%.

¹ H NMR (CDCl ₃ , 300MHz) δ _ppm : 7.45-7.36 (m, 5H), 5.88 (br s, 1H), 5.75 (br s, 1H), 5.26-5.19 (m, 4H), 4.15 (brs). , 2H), 3.85 (brs, 2H).

Figure 4

Example 3: Preparation of N, N'-diallyl-4-methylbenzenesulfonamide 2 (Scheme 5).

A solution of toluenesulfonamide (5 g, 29 mmol) in THF (10 ml) is added to a suspension of NaH (1.39 g, 58 mmol) in THF (130 ml) at 0 ^° C. The reaction medium is allowed to return to room temperature, then it is heated to 60 ⁰ C until a white foam is obtained, then cooled to room temperature and stirred for 15 minutes. minutes. A solution of allyl bromide (7.5 ml, 87 mmol) in THF (10 ml) is added to the reaction medium. After 24 hours of reaction at 60 ^° C., water is added. The organic phase is separated from the aqueous phase and then dried over Na ₂ SO 4. The solvent is evaporated and the product is purified by chromatography on silica gel using as eluent. EtOAc / Hexane (1/4). We obtain 2 with a yield of 20%.

¹ H NMR (CDCl ₃ ) δ _ppm : 7.70 (d, 2H), 7.28 (d, 2H), 5.67 (m, 2H), 5.15 (d, 4H), 3.80 (d, 4H), 2.41 (s, 3H); ).

Example 4: Preparation of enynes

General method for the synthesis of enynes (H. Clavier, S.P. Nolan, Chem.Europ.J., 2007, 13, 8029-8036):

In a suspension of sodium hydride (NaH) in anhydrous DMF, a solution of ynol and distilled and degassed THF are added dropwise at 0 ^° C. After stirring for 15 minutes, the allyl bromide is added and the reaction is left at room temperature for 2 hours. Water is added and the product is extracted with ethyl acetate. The organic phase is washed with saturated aqueous solutions of Na ₂ CO ₃ and NaCl and is then dried with sodium sulfate. The solvent is evaporated and the product obtained is purified by chromatography column on silica gel. a) Synthesis of 2- (allyloxy) but-3-yn-2-yl) benzene 9:

The reagents, namely sodium hydride (11 mmol, 264 mg), 2-phenyl-3-butyn-2-ol (10 mmol, 1.46 g) and allyl bromide (11 mmol, 1 ml ) are mixed using the general method above. The product was purified by silica gel chromatography column using pentane / ethyl ether (98: 2) as eluant, and a product was obtained as a colorless oil (1.71 g, 92%).

¹ H NMR (CDCl ₃ , 250 MHz) δ _ppm : 7.66-7.62 (m, 2H, CH ^Ar ), 7.42-7.37 (m, 2Η, CH ¹ *), 7.35-7.31 (m, 1H, CH ^* ) , 5.97 (ddt, 1Η, CH =CH ₂ ), 5.32 (dq, 1H, CH ₂ = CH), 5.17 (dq, 1H, CH ₂ = CH), 4.12 (ddq, 1H, CH ₂ O), 3.70 ( ddq, 1Η, CH ₂ O), 2.77 (s, 1Η, CHC), 1.80 (s, 3Η, CH ₃ ).

b) Synthesis of 1- (allyloxy) prop-2-yn-1,1-diylbibenzene 10:

The reagents, namely sodium hydride (11 mmol, 264 mg), 1,1-diphenyl-2-propyn-1-ol (10 mmol, 2.08 g) and allyl bromide (11 mmol, mL) are mixed using the general method above. The product is purified by column chromatography on silica gel using pentane / ethyl ether (98: 2) as eluent. The product is obtained in the form of a colorless oil (2.21 g, 89%).

¹ H NMR (CDCl _3, 250 MHz) Ap _pm: 7.62 (d, 4H, CH ^*), 7.36 (t, 4H, CH * ^1), 7.38 (t, 2H, CH ^*), 6.09-5.99 ( m, 1H, CH = CH ₂ ), 5.41 (d, 1H, CH ₂ = CH), 5.17 (d, 1H, CH ₂ = CH), 4.09 (d, 2H, CH ₂ O), 2.93 (s, Η; CHC).

Example 5: General procedure for the metathesis reaction: RCM or ROMP of olefins under an inert atmosphere.

In a Schlenk tube containing a diallyl compound, 0.1% of Grubbs catalyst ^2nd generation, 2.5 wt% dendrimer 17 and an amount of water well degassed to have a concentration of 0.1M. After a few hours of vigorous stirring under a nitrogen atmosphere, the aqueous solution is filtered with a millipore filter, and the reaction product is then extracted with ethyl ether. The dendrimer remains in the aqueous phase because it is not soluble in ethyl ether. The Grubbs catalyst, which has been stuck on the walls of the Schlenk, can be reused.

The product obtained is characterized either by gas chromatography or NMR Η.

0.1 mole% of Grubbs catalyst ^2nd generation at room temperature for 3h. f ^e 0.1 mol% of Grubbs catalyst ^2nd generation at room temperature for 8h. The products are characterized by H-NMR or by chromatography in gas phase: CPG chromatography apparatus used: HEWLETT PACKARD 5890 SERIES II Programming:

¹ H NMR (CDCl ₃ , 300 MHz). Product 5: δ _ppm : 5.67 (s, 2H), 1.99 (m, 4H), 1.60 (m, 4H).

¹ H NMR (CDCl ₃ , 300MHz). Product 7: δ _ppm : 5.61 (s, 2H), 4.26 (m, 4H), 3.02 (s, 4H), 1.29 (m, 6H).

Using 0.04% catalyst for 72 hours with the substrate 3, the other conditions being identical, the product 7 is obtained with a yield of 66%.

Example 6: General Procedure for the Metathesis Reaction: RCM or Olefin RMP in an Atmosphere of Air

In a Schlenk tube containing compound 3, 0.2% of

Grubbs ^2nd generation, 2.5 wt% dendrimer 17 and an amount of water not degassed so as to obtain a having a concentration of 0.1 M. After 24 h of vigorous stirring in air, the aqueous solution is filtered with a filter millipore, and the product of reaction 7 is then extracted with ethyl ether.

The yield of the reaction is 98%.

Using a catalyst amount of 0.04%, 44% product was obtained.

Example 7: General procedure for the metathesis reaction: RCM of enynes under an inert atmosphere.

In a Schlenk tube containing 9 or 10 was added 2% of Grubbs catalyst ^2nd generation, 2.5 wt% dendrimer branches 27 PEG 18 and an amount of water not degassed so as to obtain a concentration equal to 0.1 M After stirring vigorously for 24 hours in air, the aqueous solution is filtered with a millipore filter, and the reaction product is then extracted with ethyl ether. Cycle closure metathesis reactions with 2% cat. Grubbs ^2nd generation and 2.5% by weight of dendrimer having branches 27 polyethylene glycol long chain 25 ⁰ C for 24 hours under nitrogen

Example 8: General procedure for the metathesis reaction: CM of olefins under an inert atmosphere.

In a Schlenk tube containing 9-decen-l-ol (1.12 mmol) and methyl acrylate (3 equiv., 3.36 mmol) was added 2% of Grubbs catalyst ^2nd generation, 2.5 wt% dendrimer (see below) and a quantity of well degassed water to have a concentration equal to 0.1 M. After 24 hours of vigorous stirring under a nitrogen atmosphere, the aqueous solution is filtered with a millipore filter. The product of the reaction is then extracted with ethyl acetate and then purified by chromatography column on silica gel using pentane / ethyl ether (90:10) as eluent. A product is obtained in the form of a colorless oil (0.158 g, 66%).

For the catalysis, two types of dendrimers were used: the dendrimer comprising 27 long chain polyethylene glycol branches 18, and the dendrimer comprising 81 short chain polyethylene glycol branches 19. The yield obtained was 66% in both cases.

¹ H NMR of the product (CDCl ₃ , 250 MHz) δ _ppm : 6.96 (m, 1H, CH = CH), 5.84 (dd, 1Η, O ₂ CCH), 3.72 (s, 3Η, CH ₃ O), 3.63 (t, 2Η, CH ₂ OH), 2.18 (q, 2H, CH ₂ CH), 1.30 (m, 12H, CH ₂ CH ₂ ).

Example 9 Kinetics of the metathesis reaction with the substrate 3 (same conditions as in Example 5)

Example 10: Study of the proportion of catalyst on the RCM metathesis reaction with the substrate 3:

Metathesis ring closure reactions of the substrate 3 with 2.5% by weight of dendrimer comprising 27 branches of polyethylene glycol at 25 ^° C. for 24 hours under a nitrogen atmosphere.

Table III

EXAMPLE 11 Study of the Recycling of the Catalyst and the Dendrimer on the RCM Metathesis Reaction with the Substrate 3 (Same Conditions as in Example 5)

Once the catalysis reaction is complete, the amount of catalyst adhered to the walls of the Schlenk tube and the millipore filter is recycled. By extracting the reaction product with ethyl ether, the polyethylene glycol dendrimer remains in water and is recycled. The catalyst and the dendrimer were recycled three times.

Claims

1. Use of at least one amphiphilic dendrimer, water-soluble, and at least one ruthenium catalyst, for the implementation of metathesis reactions of olefins or enynes, in aqueous medium, without organic solvent.

The use of claim 1, wherein said dendrimer and said catalyst are not covalently associated.

Use according to claim 1 or 2, wherein the ruthenium catalyst is insoluble in water and / or said olefins or enynes are insoluble in water.

4. Use according to one of claims 1 to 3, wherein said metathesis reaction is carried out under an inert atmosphere, in particular under nitrogen, or in an atmosphere consisting of air.

5. Use according to one of claims 1 to 4, wherein said metathesis reaction is carried out in a temperature range of about 20 ⁰ C to about 65 ° C, preferably 40 ⁰ C to 60 ⁰ C, including from 20 ^° C. to 40 ^° C., in particular from approximately 20 ° to 25 ° C.

6. Use according to one of claims 1 to 5, wherein said ruthenium catalyst is a catalyst of Grubbs 1 or 2, or Hoveyda-Grubbs 1 or 2, in a proportion of about 0.01 mol% to 5% in mole.

7. Use according to one of claims 1 to 6, wherein said catalyst is used in a proportion of about 0.04 mol% to about 0.2 mol%, preferably about 0.1 mol%, or in a proportion of about 0.1 mole% to about 0.3 mole%, preferably about 0.15 mole% to about 0.25 mole%, particularly about 0.2 mole%, or in a proportion of about 1 mole% to about 3 mole%, preferably about 1.5 mole% to about 2.5 mole%, particularly about 2 mole%, or about 1 mol% to about 3 mol%, preferably about 2 mol% to about 3 mol%, more preferably about 2 mol%, or about 1 mol% to about 5 mol% preferably from about 3 mol% to about 5 mol%, in particular about 2 mol%, or from about 3 mol% to about 5 mol%, preferably from about 4 mol% to about 5 mol%. about 5 mol%, especially about 5 mol%.

8. Use according to claim 1 to 7, wherein said catalyst and the dendrimer are reusable, at the end of the first metathesis reaction, for a subsequent metathesis reaction, in particular in at least one subsequent metathesis reaction to about ten subsequent metathesis reactions, preferably in at least one to about

5, especially in at least one to three.

9. Use according to one of claims 1 to 8, wherein said dendrimer is in a proportion of about 0.01 mol% to about 0.1 mol%, preferably about 0.01 mol% to about 0.05%, more preferably from about 0.01 mol% to about 0.03 mol%, even more preferably from about 0.015 mol% to about 0.025 mol%, particularly about 0.02 mol%. % in mole.

The use according to claim 9, wherein said dendrimer has the following general formula (I):

A - [(L) _r B] _x (I) in which A corresponds to a hydrophobic core, L corresponds to an optionally present spacer, and B corresponds to an amphiphilic part comprising a dendron consisting of amphiphilic terminations, x corresponds to a number integer from 2 to 6, i corresponds to an integer from 0 to 1, and said dendrimer having a molecular weight of from 5000 to 90000, preferably from 7212 to 76509, more preferably from 8787 to 28153, still more preferably from 8787 to 23349 and a hydrophilic balance lipophilic (HLB) of from 14 to 20, in particular from 15.59 to 17.41.

The use according to claim 10, wherein said dendrimer has the following general formula (II):

A- [CL] ₁ -B] ₃ (H)

in which :

A represents a hydrophobic core of general formula III:

in which (X) m represents:

L represents a spacer, of general formula (IV)

in which (X) m 'represents

where m 'is an integer equal to 1, 2 or 3, and k is an integer equal to 0, 1 or 2 and when m

= 1, then k = 2; when m = 2, k = 1 and when m = 3, k = 0,

(IV) being bonded to (X) m, p = 1 to 1θ, especially 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and in particular 1 or 2, i = 0 or 1

- B represents: a group comprising a triazole connected to a dendron having a ring, in particular aromatic, on which are grafted amphiphilic molecules, preferably located at the end of said dendron, which amphiphilic molecules consist in particular of PEG.

12. Use according to claim 10 or 11, wherein said hydrophilic molecules consist of 9 to 243 PEG, preferably 27 to 81.

13. Use according to one of claims 10 to 12, wherein the number of dendrons is from 9 to 27 and the number of PEG per dendron is 1, 2 or 3, in particular 3, said dendrons comprising a chain:

Y (or short):

, or Z (or long):

14. Use according to one of claims 10 to 13, wherein the dendrimer is selected from the following molecules:

excluding the following dendrimers:

15. Dendrimer of the following general formula (I):

A - [(L) _r B] _x (I) in which A corresponds to a hydrophobic core, L corresponds to an optionally present spacer, and B corresponds to an amphiphilic part comprising a dendron consisting of amphiphilic terminations, x corresponds to a number integer ranging from 2 to 6, i corresponds to an integer from 0 to 1, and said dendrimer having a molecular weight of from 5000 to 90000, preferably from 7212 to 76509, more preferably from 8787 to 28153, still more preferably from 8787 to 23349 and a hydrophilic-lipophilic balance (HLB) of from 14 to 20, in particular from 15.59 to 17.41; excluding dendrimers following: - 27 PEG dendrimer long chain: C4i4H ₇ 4iOi53N27Si9

16. Dendrimer according to claim 15, of the following general formula (II):

A - [(L) _r B] ₃ (H)

in which :

A represents a hydrophobic core of general formula III:

in which (X) m represents:

L represents a spacer, of general formula (IV)

in which (X) m 'represents

(IV) being bound to (X) m,

P = 1 to 10, especially 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and in particular 1 or 2, i = 0 or 1

B represents: a group comprising a triazole linked to a dendron comprising a ring, in particular an aromatic ring, on which are grafted amphiphilic molecules, preferably located at the end of said dendron, which amphiphilic molecules consist in particular of PEG, said dendrimer having a molecular weight from 5000 to 90000, preferably from 7212 to 76509, more preferably from 8787 to 28153, still more preferably from 8787 to 23349 and a hydrophilic-lipophilic balance (HLB) of from 14 to 20, especially from 15.59 to 17, 41.

17. Dendrimer according to claim 15 or 16, wherein said hydrophilic molecules consist of 9 to 243 PEG, preferably 27 to 81.

18. Dendrimer according to one of claims 15 to 17, wherein the number of dendrons is from 9 to 27 and the number of PEG by dendron is 1, 2 or 3, in particular 3, said dendrons comprising a chain:

n being 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, in particular n = 5 between said ring of said dendron and the imidazole of said dendrimer, the cycle bonding of said dendron being effected on the right of the said chain.

19. Dendrimer according to one of claims 15 to 18, selected from the following molecules: - dendrimer 27 PEG short chain: C ₃₄₂ HsC) ₇ O ₁₁₇ N ₂₇ SIg

20. Process for carrying out metathesis reactions of olefins or enynes comprising a step of contacting a dendrimer, as defined in claims 15 to 19, and a ruthenium catalyst with an olefin initial or an initial enyne, in aqueous medium, without organic solvent, to form a final olefin, said catalyst and said dendrimer being optionally recovered after formation of the final olefin.

21. The process according to claim 20, wherein the proportion of dendrimer is from about 0.01 mole% to about 0.03 mole%, preferably from about 0.015 mole% to about 0.025 mole%, particularly about 0.02 mol%.

22. The method of claim 20 or 21, wherein the ruthenium catalyst is insoluble in water and / or said olefins or enynes are insoluble in water.

23. Method according to one of claims 20 to 22, wherein said metathesis reactions are performed under an inert gas or in an atmosphere consisting of air.

24. Method according to one of claims 20 to 23, wherein the temperature range is from about 20 ⁰ C to about 65 ° C, preferably from about 40 ⁰ C to about 60 ⁰ C, including about 20 ⁰ C to about 40 ⁰ C, in particular from about 20 ⁰ C to about 25 ° C.

25. The method according to one of claims 20 to 24, wherein the metathesis reaction is a RCM, consisting of the following steps: a. contacting a dendrimer, as defined in claims 15 to 19, with a ruthenium catalyst in an amount of from about 0.04 mole% to about 0.2 mole%, particularly about 0 , 1 mol%, with an initial olefin selected from dienes, contained in a non-airtight container, b. adding a quantity of degassed water to the above container to obtain an olefin, catalyst and dendrimer mixture in the water, and c. agitating the aforesaid mixture in water, under a nitrogen atmosphere at room temperature for a time necessary for the cyclization and complete disappearance of said diene.

26. Method according to one of claims 20 to 24, wherein the metathesis reaction is a RCM, consisting of the following steps: at. contacting a dendrimer, as defined in claims 15 to 19, with a ruthenium catalyst in an amount of from about 0.1 mol% to about 0.3 mol%, preferably from about From 0.15 mol% to about 0.25 mol%, in particular about 0.2 mol%, with an olefin selected from dienes, contained in a container in contact with air, b. adding a quantity of non-degassed water to the above container to obtain an initial olefin mixture, catalyst and dendrimer in water, and c. agitating the aforesaid mixture in water, in an atmosphere consisting of air at room temperature for a time necessary for the cyclization and complete disappearance of said diene.

27. Method according to one of claims 20 to 24, wherein the metathesis reaction is a RCM, consisting of the following steps: a. contacting a dendrimer, as defined in claims 15 to 19, with a catalyst in an amount of from about 1 mol% to about 3 mol%, preferably about 1.5 mol% at about 2.5 mol%, especially about 2 mol%, with an initial enyne contained in a non-airtight container, b. adding a quantity of degassed water to the above container to obtain an initial enyne mixture, catalyst and dendrimer in water, and c. stirring said mixture in water, under a nitrogen atmosphere at room temperature for a time necessary for the cyclization and disappearance of said initial enyne.

28. Method according to one of claims 20 to 24, wherein the metathesis reaction is a RCM, consisting of the following steps: the contacting of a dendrimer, as defined in claims 15 to 19, and of a catalyst in an amount of from about 1 mole% to about 3 mole%, preferably from about 2 mole% to about 3 mole%, particularly about 2 mole%. at. with an initial enyne contained in a container in contact with the air, b. adding a quantity of non-degassed water to the above container to obtain an initial enyne mixture, catalyst and dendrimer in water, and c. agitating said mixture in water, in an atmosphere consisting of air at room temperature for a time necessary for the cyclization and disappearance of said initial enyne.

29. Method according to one of claims 20 to 24, wherein the metathesis reaction is a ROMP, consisting of the following steps: a. contacting a dendrimer, as defined in claims 15 to 19, with a catalyst in an amount of from about 0.04 mole% to about 0.2 mole%, particularly about 0.1 mole mole%, with an initial olefin, selected from cyclic olefins, contained in a container not in contact with air, b. adding a quantity of degassed water to the above container to obtain an initial olefin mixture, catalyst and dendrimer in water, and c. agitating said mixture in water under a nitrogen atmosphere at room temperature for a time necessary for opening and complete disappearance of said cyclic olefin.

30. The method according to one of claims 20 to 24, wherein the metathesis reaction is a ROMP, consisting of the following steps: a. contacting a dendrimer, as defined in claims 15 to 19, with a catalyst in an amount of from about 0.1 mole% to about 0.3 mole%, preferably about 0, From about 15 mole% to about 0.25 mole%, especially about 0.2 mole%, with an initial olefin selected from cyclic olefins contained in a container in contact with air, b. adding a quantity of non-degassed water to the above container to obtain an initial olefin mixture, catalyst and dendrimer in water, and c. agitating the aforesaid mixture in water under an atmosphere consisting of air at room temperature for a time necessary for opening and the complete disappearance of said cyclic olefin.

31. The method according to one of claims 20 to 24, wherein the metathesis reaction is a CM, consisting of the following steps: a. contacting a dendrimer, as defined in claims 15 to 19, with a catalyst in an amount of from about 1 mol% to about 5 mol%, preferably from about 3 mol% to about 5 mol%, in particular about 2 mol%, with a mixture of two identical initial olefins, in particular allyl alcohol or 9-decenoic acid, or different, in particular 9-decen-l-ol and methyl acrylate, or 4-vinylcyclohexene-1,2-epoxide and butyl acrylate, contained in a container not in contact with air, b. adding a quantity of degassed water to the above container to obtain an initial olefin mixture, catalyst and dendrimer in water, and c. stirring of the above mixture in water, under a nitrogen atmosphere at about 60 ⁰ C for a time necessary for the formation of the final olefin.

32. The method according to one of claims 20 to 24, wherein the metathesis reaction is a CM, consisting of the following steps: a. contacting a dendrimer, as defined in claims 15 to 19, with a catalyst in an amount of from about 3 mol% to about 5 mol%, preferably from about 4 mol% to about 5 mol%, in particular about 5 mol%, with a mixture of two identical initial olefins, in particular allyl alcohol or 9-decenoic acid, or different, in particular 9-decen-1-ol and methyl acrylate, or 4-vinylcyclohexene-1,2-epoxide and butyl acrylate, contained in a container in contact with air, b. adding a quantity of non-degassed water to the above container to obtain a mixture of initial olefins, catalyst and dendrimer in water, and c. stirring of the above mixture in water under an atmosphere consisting of air at about 60 ^° C. for a time necessary for the formation of the final olefin.