FR2993557A1 - SYNTHESIS OF METHYL PROPANE DIOL FROM ALLYL ALCOHOL - Google Patents

Abstract

The subject of the present invention is a process for the synthesis of 2-methyl-propane-1,3-diol (MPD) from allyl alcohol (2-propen-1-ol), comprising a first step of hydroformylation of allyl alcohol followed by a second reduction step of 2-methyl-3-hydroxy-propanaldehyde obtained in the first step, said process being preceded by a preliminary step of synthesis of allyl alcohol by dehydration of glycerol, said dehydration can be direct or indirect. The process according to the invention is characterized by the use of a selective hydroformylation catalyst consisting of a rhodium complex associated with a diphosphine ligand having a specific bite angle of less than or equal to 90 °, preferably of between 75 and 90 °.

Description

TECHNICAL FIELD The present invention relates to a process for the synthesis of 2-methyl-propane-1,3-diol (MPD) from allyl alcohol (2-propen-1-o1). It also relates to a method for synthesizing 2-methyl-propane-1,3-diol (MPD) including the above process but preceded by a preliminary step of synthesis of allyl alcohol by dehydration of glycerol, said dehydration can be direct or indirect with a dehydration of glycerol acrolein and hydrogenation to lead to allyl alcohol. 2-methyl-propane-1,3-diol is a raw material used in industry. It is used for the production of polyesters, polyurethanes, coatings, adhesives, coatings or elastomers. It can also be used as an emulsifier or as a moistening agent. STATE OF THE ART The most well-known methods for the synthesis of 2-methyl-propane-1,3-diol use 2-methylene-propane-1,3-diol-diacetate as a raw material (Bayer process, US 4,036,895 ), propylene oxide (Lyondell process) or acrolein. In the Bayer process, described in US Pat. No. 4,036,895, the feedstock of 2-methylenepropane-1,3-diol diacetate is in a first step reacted with a light aliphatic alcohol in the presence of a base to yield 2- methylene-propane-1,3-diol whose double bond is, in a second step, hydrogenated to 2-methylpropane-1,3-diol. In the ARCO / Lyondell process for the manufacture of 1,4-butanediol, the reaction is carried out. basic first is propylene oxide. The latter is, in a first step, converted by isomerization to allyl alcohol (2-propen-1-ol) of formula C1-1, - = - CH-CH2OH which is then, in a second step, subjected to a catalytic hydroformylation by CO + H2, resulting in the formation of aldehydes: 4-hydroxybutanal (about 80%) and 3-hydroxy-2-methyl-propanal (about 10%). The latter are in a last step hydrogenated in the same proportions to the corresponding diols 1,4-butanediol and 2-methyl-propane-1,3-diol. The processes using acrolein as raw material have been the subject of many studies. These are summarized in the publications of Ohgomori et al. J. Mol. Cafe A: ChemicaL 1995, 96, 25 and Ind. Eng. Chem. Res. 1995, 34, 971, These methods are based on a hydroformylation reaction of acrolein. They have two variants: a direct method and an indirect method. In the direct process, acrolein is subjected to hydroformylation in the presence of a rhodium catalyst resulting in a linear and branched dialdehyde monomer which is then hydrogenated to form the corresponding cliols. The results are unsatisfactory because it is difficult to control the reaction to stop dialdehyde stage resulting in the formation of significant by-products. In the indirect method, acrolein is first reacted with 2-methyl-propane-1,3-cliol (MPD) to form the corresponding acetal, 2-vinyl-5-methyl- 1,2-propanediol (VMD) which is subjected to hydroformylation leading to a mixture of cyclic acetal aldehydes, one linear and the other branched, which are then reduced by hydrogenolysis / hydrogenation and then hydrolyzed to form 1,4-butanediol (BDO) and 2-methyl-propane-1,3-diol (II / 1PD). In these various processes, the hydroformylation of olefins which has been known since the end of the 1930s is used. It consists in reacting the CO 2 + 2 mixture on the double bond of the olefin to lead to the formation of an aldehyde with addition of a carbon to the initial olefin. This reaction is conducted in the liquid phase under relatively severe temperature and pressure conditions in an organic solvent using homogeneous catalysis. The catalysts used are generally cobalt or rhodium complexes. The aldehyde formed is generally subsequently subjected to a reduction reaction to form an alcohol, to a reductive amination to give an amine, an oxyesterification reaction to give an ester or an oxyclaton to give an acid. The study of the hydroformylation of unsaturated alcohols and in particular of allyl alcohol (CH2 = CH-CH2OH) has been the subject of numerous works since the end of the 1970s, mainly by the companies KURARAY, ARCO and more. recently LYONDELL. One of the main objectives of this work was the synthesis of 1,4-butanediol. Mention may be made in this regard of French Pat. Nos. 79 14186 (Pub. 2428021) and its corresponding US Pat. No. 4,238,419, US Pat. No. 4,215,077 and US Pat. No. 4,306,087, all filed in the name of KURARAY, which relate in particular to the use of phosphines associated with a rhodium complex. With respect to ARCO, US Pat. Nos. 5,290,743; 6,127,584 and 6,225,509 which describe the catalysts used based on rhodium and phosphine ligands, such as alkylphosphines (US 6,127,584) or diphosphines (US 6,225,509), and the operating conditions of temperature, pressure, H2 / CO ratios, etc., as well as As for the reaction and the resistance of the catalyst, LYONDELL, which exploits the ARCO process, has more recently filed a claim W008 / 121194 which claims for the reaction of synthesis of 1,4-butanediol the use in the hydraformylation step of a specific phosphine ligand associated with the rhodium complex to obtain a very high selectivity of 4-hydroxybutanaldehyde and thus 1,4-butanediol. The dehydration of glycerol to allyl alcohol has been the subject of much earlier academic work, including the article by Oliver Kamm and CS Marvel (Organic Syntheses, Col / 1941, Vol 1, p. 2-step reaction in which the formic acid is reacted under heat (temperature between 195 and 260 ° C.) on the glycerol which leads to the transient formation of the mono-formate decomposed into allyl alcohol with formation of CO2 and H 2 O More recently, a team from the University of California (Berman et al.) Has resumed work on this type of process, a reaction of formic acid with glycerol, working in an inert atmosphere (patent application VVO 2008 / 092 115). For processes of this type, mention may be made of recent work on the direct catalytic dehydration of glycerol to allyl alcohol which has been made per Liu et al. who published an article in Journal of the Royal Society of Chemistry, Chem. Commun., 2010, 46, 1238-1240, entitled "From .glycerol to allyl alcohol Iron oxide catalyzed dehydration and subsequent hydrogen transfer", which describes the direct dehydration of glycerol in the presence of an iron catalyst (Fe 2 O 3) followed by a transfer of hydrogen according to the following process: CH 2 OH -CHOH-CH 2 OH (-2 H 2 O) 4 CH 2 = CH-CHO + 2 HI-1 CH 2 = CH-CH 2 0 1 -1, I-1 The symbol H signifies that it is In addition, in the context of a thesis supported by A. Ülgen at the University of Aachen available on the internet under the reference: http://darwin.bth.rwthaachen.de / oo Ivolitexte / 2010/3078 / pdf / 3078..pct. the latter has described the direct dehydration of glycerol to ally alcohol at a temperature between 260 and 320 ° C, in the presence of a supported mixed oxide molybdenum-tungsten on TiO 2 catalyst. The mechanism proposed for this reaction, simpler than the previous one, is the following: CH 2 OH -CHOH-CH 2 OH (-H 2 O, -1/202) CH 2 = CH-CH 2 OH. 10 Finally, we can find the article of Satoshi Sato and a /. "Selective dehydration of diors to allylic alcohols catalyzed by ceria" published in Catalysis Communications 2003, 4, 77-81 which describes the dehydration of linear diols to allylic alcohols at high temperature (300 to 400 ° C.) in the presence of cerium oxides. possibly associated with another meta-oxide. As can be seen, the various prior art PDM synthesis methods have disadvantages. The Bayer process, for example, uses a "sophisticated" and therefore expensive raw material. Processes based on the hydroformylation of acrolein are either inefficient with the formation of by-products in large quantities (the direct route), or complicated (the indirect way! By multiplying the steps to protect (then protect) During the course of the hydroformylation of the aldehyde function, which entails a considerable additional cost, the ARCO / Lyondell industrial scale process is dedicated to the synthesis of 1,4-butanediol and the selectivity to 2-methylpropane. 1,3-diol is particularly weak since it is only a co-product of the basic process, and in addition all these processes systematically use raw materials, whereas for many years it has been recommended to The applicant has decided to overcome these various disadvantages and for this has been directed towards the development of a process for synthesizing 2-m. ethyl-propane-1,3-diol from allyl alcohol .permettan '. It will result in high conversion rates of allyl alcohol while maintaining a high selectivity to 2-methyl-1,3-propanediol relative to 1,4-butanediol.

SUMMARY OF THE INVENTION AND DESCRIPTION OF EMBODIMENTS The subject of the present invention is a process for the synthesis of 2-methyl-propane-1,3-diol from allyl alcohol (CH2 = CH-CH2OH) consisting in a first step: to subject the allyl alcohol to selective hydroformylation in the presence of a rhodium-based catayser associated with at least one diphosphine ligand having a bite angle less than or equal to 90 °, leading to the formation of 2 -methyl-3-hyciroxy-propanaldehyde which in a second step is reduced by hydrogenation of the aldehyde double bond to form 2-methyl-propane-1,3-diol. The process of the invention is essentially characterized by the use of a rhodium complex catalyst associated with a diphosphine ligand having a specific bite angle of less than or equal to 90 °, preferably between 75 and 90 ° and preferably between 80 and 85 °. The definition of bite angles of bidentate ligands is given in "DesigningLigands with the Right Bite", Chemtech, September 1998, pp 27-33. The reaction scheme 1 of the process, wherein L is the phosphine ligand, is as follows. CH 2 OH-CH = CH 2 + H 2 / CO (Rh-L) CCH-CH (CH 3) -CH 2 OH [) CH-CH (CH 3) -CH 2 OH + H 2 "- CH 2 O -CH (CH 3) -CH 2 OH The first step of the process is carried out under the following operating conditions. The reaction is conducted in a liquid phase in a solvent. Any type of organic solvent can be used in the hydroformylation according to the invention, provided that it does not disturb this reacor-i. The starting compounds (allyl alcohol), the product aldehydes and their condensation products may be solvents for the reaction. Other suitable solvents are, for example, aromatic hydrocarbons such as benzene, toluene, xylene and dodecylbenzene, tetralin, diphenyl ether, alicyclic hydrocarbons such as cyclohexane, ethers such as clibutyl ether, ethylene glycol dimethyl ether, and the like. , diethylene glycol ether, triethylene glycol dimethyl ether, tetrahydrofuran, oxane, and enteras such as diethyl phthalate and dioctyl phthalate, ethyl acetate, ethyl formate, nitriles such as propionitrile. acetonitrile, alcohols such as methanol, ethanol and isopropanol, ketones such as acetophenone, halogenated hydrocarbons such as chlorobenzene, dichloroniethane, 4-chloroanisole, 2-chloroanisole, 4-bromoanisole, 2-bromoanisole. 1,2-dichlorohenzene, 1,2,4-trichlorobenzene, dibromonaphthalene, bis (2-chloroethyl) ether, chloroform, the reaction is conducted in the liquid phase preferably in a solvent medium such as toluene, ethanol or phthalates. The reaction temperature is between 20 and 150 ° C., preferably between 40 and 140 ° C. and more preferably between 60 and 120 ° C. The reaction is carried out under a pressure of between 1 and 300 bar, preferably between 3 and 70 bar, and even more preferred between 3 and 30 bar. Maintaining as low a pressure as possible has a favorable effect on the performance of the process. The ratio in molar equivalents [Ligand diphosphite Ilrhodium] will generally be between 1 and 20 and preferably between 2 and 5. The use of a slight excess of ligand will promote the hydroformylation reaction, however having the disadvantage of a substantial additional cost, because of the price of these products The ratio [Substrate] i [Rn] in molar equivalents is generally between 50 to 50000, preferably between 500 to 10000, preferably between 200 and 2000 and even more preferred between 500 and 1000.

The ratio H2 / CO is preferably between 0.1 and 10, preferably 0.5 and 5 and more preferably between 0.5 and 1.5. The reaction system may also include inert gases such as nitrogen, helium, argon, methane, ethane, propane, butane and carbon dioxide. Rhodium complexes useful as catalytic precursors in the process of the invention are well known to those skilled in the art. Any rhodium source capable of forming a soluble rhodium carbonyl complex in the reaction medium may be suitable. This compound of Rh may thus be, by way of non-limiting examples, hexarhodium hexadecylcarbonyl (Rh6 (CO) 16), simple salts such as Rh (III) trishalides such as RhI3, RhBr3, RhCl3 and their hydrated salts , Rh (NO3) 3, or Rh (acac) 3 (acac = acetylacetonate), or complexes such as Rh (CO) 2 (acac), [RhCl (cyclooctadiene) 1, [RhCl (norbornadiene) 212. use rhodium acetylacetonate dicarbonyl rh (CO) 2 (acac).

By way of nonlimiting examples of diphosphine ligands that can be used in the process of the invention, mention may be made of 1,2-bis (diphenylphosphino) ethane (dppe), 1,2-bis (dimethylphosphino) ethane (dmpe), 1,2-bis (dicyclohexylphosphino) ethane (dope), 1,2-bis (di (pentafluorophenyl) phosphino) ethane (dfpe), 1,2-bis (diphenylphosphino) benzene (dpp-benzene), 2-bis (dimethoxyphosphino) ethane (PomPom). Ph2P PPh2 Me2P P e Cy2P PCy2 (C6F5) 2P P (C6F5) 2 Ph2P PPh2 Dppe Dmpe Dcpe Dfppe Dpp-benzene Ph2P PP112 (IVIe0) 2P P (OWle) 2 OPPm PornPom The temperature conditions selected also depend on the solvent used and procedures for separating the product hydroxyaldehyde before it is sent to the next hydrogenation stage. The procedures for separating the hydroxydehyde (hydroxyaldehydes) may take a number of different forms such as distillation, distillation under reduced pressure, liquid-liquid extraction depending in particular on the solvent and / or the catalyst used. The temperature in the distillation separation step is 50 ° C to 200 ° C. Reaction temperatures above 150 ° C and distillation temperatures greater than 200 ° C or even 100 ° C may cause a reduction in catalyst activity and / or thermal decomposition of the catalyst and / or degradation of the aldehydes. products. In the case where the aldehydes produced have boiling points which are relatively lower than that of the solvent, they may be separated by distillation, possibly under reduced pressure, the distillation residue containing the catalyst components being returned to the hydroformylation step. .

In the case where the produced aldehydes have boiling points relatively higher than that of the solvent, they can be driven by liquid-liquid extraction, the. residue containing the catalyst components being returned to the hydroformylation step. In the case of thermally unstable products such as hydroxyaldehydes derived from allyl alcohol, it is advantageous to separate the products by extraction with a solvent. It is for example recommended not to operate at a temperature above 90 ° C, the products may then degrade rapidly. An appropriate method of separation is by water extraction and recycation of the catalyst-containing residue in the hydroformylation step. It may then be desirable to subject this residue to a catalytic activation step prior to a new reaction cycle. The amount of water used in the extraction step is preferably between 0.5 and 1.5 times the volume of reaction mixture from the hydroformyl. The water used may also contain other inert substances for the downstream stages, such as butanediol-1,4 (BDO) or 2-methyl-1,3-propanediol (rIPD). Water can largely be replaced by these diols.

In the case where the rhodium catalyst is preferentially soluble in the aqueous fraction, recovery means such as adsorbent resins can be used to limit rhodium losses, in a preferred embodiment of the process of the present invention. In the invention, it will be possible to proceed to the end of the first step to a separation of the two aldehydes 3-hydroxy-2-methyl-propanaldehyde and 4-hydroxybutyraldehyde, formed during this step in order to avoid that the separation must take place at the alcohol stage. ulterior. The two hydroxyaldehydes can be separated by distillation under reduced pressure. The calculated boiling point (ACD-Lab method) for 4-hydroxybutyraiddehyde is 196 ° C at atmospheric pressure and therefore about 90 ° C at 20 mm Hg. The boiling point calculated for 3-hydroxybutyrate 2-methylpropanaldehyde is 162 ° C. at atmospheric pressure and therefore about 50 ° C. at 20 mmHg. The second step of the process for the reduction by hydrogenation of the aldehyde function is carried out in a conventional manner in the presence of a catalyst. hydrogenation such as nickel, palladium, platinum, cobalt, etc. The reduction can be carried out by hydrogenation in aqueous solution of the hydroxyaldehydes using conventional methods. Suitable hydrogenation catalysts include Raney nickel, nickel supported on alumina, copper, copper chromite, cobalt, palladium, platinum and other well known catalysts. The hydrogenation reaction is carried out at a pressure between 10 and 50 bar and at a temperature between 40 and 200 ° C. In this regard, reference can be made to the documents Chem. Systems Report 86-3-1, December 1987, entitled "1,4-Butanediol from any! alcohol "and its references as well as Process Economics Report 96B" polybutylene terephthalate and butanediol "October 1997 (PEPI95 96B). With regard to the type of reactors to be used in the process, there is a wide choice.

For example, a so-called slurry reactor or a multitubular fixed bed reactor can be used. The process of the invention also relates to a process for the synthesis of 2-methylpropane-1'3-diol by hydroformylation of allylic alcohol containing a preliminary allylic alcohol synthesis by dehydration of glycerol. .

It is known that the dehydration of glycerol generally leads to acrolein. However, it has been mentioned above that dehydration of glycerol could lead directly to allyl alcohol according to the following reactions CH 2 OH -CHOH-CH 2 O 1 (- The applicant has discovered that this reaction can be directly carried out in the presence of selective dehydration catalysts, avoiding and / or limiting the formation of acrolein. This glycerol dehydration reaction is carried out under the following conditions: Temperature between 250 and 400 ° C., preferably between 280 and 350 ° C., pressure: between 0.5 and 5 bar absolute and preferably between 1 and 3 bar The glycerol concentration of the aqueous solution is between 30 and 100% by weight, and preferably between 50 and 95% by weight.

The partial pressure of glycerol in the vapor phase is between 4 and 20%. The catalysts are selected from oxides and mixed basic oxides and having a redox function, oxides in bulk or supported form. Possible supports that can be used include alumina, titania, zirconia, hydrotalcites and hydroxyapatites. The metal oxides that can be used include those of Nickel, Iron, Cuba, Copper, Molybdenum, Rhenium, Tin, Antimony, Bismuth, or metals such as Palladium, Ruthenium, etc. Preferably, Ni / Al 2 O 3, Co-Mo / Al 2 O 3, Pd / Al 2 O 3, La 2 O 3 / ZrO 2, TiO 2, Mo / TiO 2, W-Mo / TiO 2, Fe 2 O 3 and CeO 2 will be used. This reaction can also be carried out optionally in the absence of catalyst and then preferably at a high temperature above 350 ° C. The process of the invention is illustrated by Examples 1 to 16 below.

Examples 1 to 12 Operating conditions A 15 ml stainless steel reactor is charged with 15 mmol of allyl alcohol in 4 ml of an organic solvent: toluene, a Rh (acac) (CO) 2 rhodium complex and a diphosphinic ligand. chosen from those mentioned above. The reaction is carried out at a pressure of 20 bar with a H 2 / CO ratio of 1/1, with the exception of Example 6 which has been carried out at a pressure of 4 bars with a H2 / CO ratio of 1/1. .

The reaction is carried out at a temperature of 100 ° C with the exception of Examples 1 (120 ° C) and 7 and 9 (70 ° C). The reaction time is 24 hours. The operating conditions specific to each test are specified in Table 1 below. Examples 12 and 13 are comparative examples with phosphines emerging from the invention.

Results In Table 1, compound 1 denotes allyl alcohol, compound 2 denotes 4-hydroxybutyraldehyde, compound 3 denotes 2-methyl-3-hydroxy-propanaldehyde and C3 denotes by-products, which are essentially products in C3.30 Table 1 Angle test of [1] / [Rh] [Ly [Rh] Conv. Yield [%] [al Ligand bite l [a) (L) [O] F / 0] 2 C3 1 dppm 72 5000 10 100 12 8 80 2 dppm 72 5000 10 65 12 8 45 dppe 85 5000 62 5 39 18 4 dppe 85 1000 5 100 58 33 dppe 85 500 2 100 11 66 23 b r- 500 2 42 1 33 8 O dppe 7 dppe 2 40 26 9 8c dppe 85 500 2 100 79 12 9C dppe 85 500 2 35 4 27 4 dfppe 88 500 2 100 10 42 48 11 dpo-benzene 83 500 2 100 11 64 25 12 Xantphos 107 500 2 100 81 O 19 130 Xantphos 107 500 2 100 82 6 12 a conversion and yields of products determined by 1H NMR and GLC condition EXAMPLE 12: The results obtained with the process according to the invention are compared with those of Examples 12 and 4, respectively, at 4 bars of CO / H 2 (1/1). 13, illustrate the high selectivity of branched compound. Examples 7 and 9 conducted at lower temperature retain the high selectivity even though the conversion of the allyl alcohol is lower. Example 6 leads to lower pressure shows excellent selectivity in connected product (ratio connected / linear), even if the conversion of allyl alcohol is also lower. EXAMPLE 14 This example illustrates the preliminary step of selectively dehydrating glycerol to allyl alcohol. The reaction is carried out under the following operating conditions. In a fixed-bed reactor, 10 g of catalyst are charged, and the operation is carried out with an hourly volume velocity of 2000. mi / h / mi catalyst. The gas flow rates are established under normal conditions of pressure and temperature. Reaction temperature 350 ° C. Pressure upstream of the reactor: 1.5 bar absolute Glycerol concentration of the aqueous solution 50% by weight Glycerol partial pressure in the vapor phase: 12%. Dilution gas: Nitrogen. The catalyst used consists of a nickel oxide on alumina (15% Ni / Al 2 O 3).

After 1 hour of reaction, the yield of allyl alcohol, measured by gas chromatography is 10% relative to the treated glycerol load. EXAMPLE 15 This example illustrates the hydrogenation step of the aldehydes produced by hydroformylation of the allyl alcohol leading to the MPD and BDO. The hydrogenation step is carried out in a stainless steel reactor of 50 ml in which the mixture is introduced. of aldehydes resulting from the hydroformylation of the allyl alcohol (example 4 of Table 1) in 10 ml of an organic solvent such as toluene. A Raney nickel-activated Ni / Al catalyst activated in water suspension is used for this reaction. The reaction is carried out under the following operating conditions: - Aldehyde and by-product mixture obtained as in Example 4 of Table 1: 400 mg - 10% Raney Ni solution in water: 2 ml - Temperature 100 ° C - Pressure: 40 bars absolute of H2 After 24 hours of reaction at 100 ° C, the conversion of aldehydes to alcohols is 40%.

EXAMPLE 16 This example also illustrates the hydrohalogenation step of the hydroformylation products derived from allyl alcohol in MPD and BDO.

The reaction is carried out, according to the same protocol as that of Example 15, under the following operating conditions Aldehyde and by-product mixture, obtained as in Example 4 of Table 1: 1.0 g - Ni solution Raney at 10% in water: 2.0 ml - Temperature: 120 ° C - Pressure 40 bars absolute of H2 After 24 hours of reaction at 120 ° C, the conversion of aldehydes to alcohols is 100%. 10

Claims (14)

CLAIMS1) Process for the synthesis of 2-methyl-propane-1,3-diol from allyl alcohol (CH2 = CH-CH201-1) consisting in a first step of subjecting the allyl alcohol to selective hydroformylation in the presence of a catalyst based on of rhodium combined with at least one diphosphine ligand having a bite angle less than or equal to 90 °, leading to the formation of 2-eiétely1-3- hydroxy-propanaldehyde which in a second step is reduced by hydrogenation of the double bond aldehyde to form 2-methyl-propane-1,3-diol. 2) Method according to claim 1 cari-2, cténsé in that the diphospnîn ligand has a bite angle included erlre 75 and 90 ° and preferably between 80 and 85 °. 3) Method according to one of claims 1 or 2 characterized in that the ratio of 15. molar equivalents [Ligand diphosphineHrhodiuml is between 1 and 20 and preferably between 2 and 5, 4) Process according to any one of the preceding claims, characterized in that the rhodium complex is chosen from hexarhodium hexadecylcarbonyl (Rhe (CO) 16) simple salts such as trishalides of Rh (III) such as Rh !. 3, RhBr3, RhCl3 and their hydrated salts, Rh (NO3) 3. Rh (acac) 3, complexes such as Rh (CO) 2 (acac), [RhCl (cyclooctadiene) 2] 2 and, [RhCl (norbornadiene) 1. 5) Process according to any one of the preceding claims, characterized in that the ligand dlellosphine is selected from 1,2-bis (diphenylphosphino) ethane (dope), 1,2-bis (dimethylphosphino) ethane (dmpe), 1 2-bis (dicyclohexylphosphino) ethane (dope), 1,2-bis (di (pentafluorophenyl) phosphino) ethane (dfpe), 1,2-bis (diphenylphosphino) benzene (dpp-benzene), and 1, 2- bis (dimethoxypho-10) ethane (PomPom). 30 6) Process according to any one of the preceding claims characterized in that the hydroformylation reaction is carried out at a temperature between 40 and 140 ° C and preferably between 60 and 120 ° C and at a pressure of between 3 and 70 bars preferably between 3 and 30 bars .. 7) Process according to any one of the preceding claims characterized in that the ratio [Substratii [Rhi in molar equivalents is between 200 and 20000 and preferably between 500 and 1000. 8) Process according to one conque of the preceding claims characterized in that the reaction is carried out with a H2 / CO molar ratio between 0.1 and 10 and preferably between 0.5 and 1.5. 9) Process according to any one of the preceding claims characterized in that the reaction is conducted in the liquid phase in a solvent such as toluene, ethanol, phthalates. 10 10) Process according to any one of the preceding claims, characterized in that the hydrogenation reaction of the aldehyde function is carried out in the presence of a hydrogenation catalyst such as nickel, palladium, platinum or cobalt. a temperature of between 40 and 200 ° C. and at a pressure of between 10 and 50 bars. 15 11) Process for the synthesis of 2-methyl-propane-1,3-diol by hydroformylation of allylic according to the method of any one of the claims pi comprising a preliminary step of synthesis of allyl alcohol by catalytic dehydration of glycerol. 12) Process according to claim 11 characterized in that the dehydration reaction of glycerol is carried out with a catalyst selected from oxides and mixed oxides basic and / or having a function redox, mass or supported oxides. 13) Process according to claim 12 characterized in that the catalyst is selected from Ni / Al 2 O 3, Co-Mo / Al 2 O 3, Pd / Al 2 O 3, La 2 O 3 / ZrO 2, TiO 2, TiO 2 / TiO 2, W-Mo / TiO 2. Fe2O3 and CeO2. 14) Process according to any one of claims 11 to 13 characterized in that the dehydration reaction is carried out at a temperature between 250 and 400 ° C and preferably between 280 and 350 ° C, and under a pressure between 0 , 5 to 5 bars absolute and preferably between 1 and 3 bars absolute.