CHIRAL FERROCENE PHOSPHINES AS LIGANDS IN ENANTIOSELECTIVE REDUCTIONS

Abstract: The present invention refers to new chiral phosphine derivatives of formula (I), wherein R1, R2, R3 and R4 are identical or different and are selected from the group consisting of hydrogen, a linear or branched C1-7 alkyl, a C5-7 cycloalkyl optionally substituted by a C1-4 alkyl, a trifluoromethyl, a halogen, a hydroxyl or an alkoxy, a phenyl optionally substituted by a C1-4 alkyl, a trifluoromethyl, a halogen, a hydroxyl or an alkoxy. The invention relates also to a process of asymmetrical synthesis for their preparation and to the use of these new chiral phosphine derivatives in asymmetric catalysis, more specifically in asymmetric hydrogenation.

Description: CHIRAL FERROCENE PHOSPHINES AS LIGANDS IN ENANTIOSELECTIVE REDUCTIONS The present invention pertains to new compounds of formula (I) , chiral phosphine derivatives, and their use in asymmetric catalysis, more specifically in asymmetric hydrogenation. The compounds of formula (I) are defined as below: R 2 ) wherein Rl, R2 , R3 and R4 are identical or different and are selected from the group consisting of hydrogen, a linear or branched Cι -7 alkyl, a C5- cycloalkyl optionally substituted by a Cι -4 alkyl, a trifluoromethyl, a halogen, a hydroxyl or an alkoxy, a phenyl optionally substituted by a C 1 -4 alkyl, a trifluoromethyl , a halogen, a hydroxyl or an alkoxy. The invention also covers all the optical active forms of the compounds of formula (I) . The synthesis of optically active functionalised compounds such as, for example, the amino acids, the mono- or dicarboxylic acids, presently presents an important industrial activity. There is therefore a requirement for catalytic systems for the synthesis of these alcohols and amines which are increasingly competitive in terms of both cost and efficacy. Known from the European patents "EP 612 758" and "EP 646 590", published by Ciba-Geigy, are catalytic systems combining a rhodium or iridium complex selected from the group consisting of [Ir(l,5- cyclooctadiene) Cl] 2/ {Rh (norbornadiene) 2 C1] 2 , or [Rh(norbornadiene) 2 ] BF 4 with an enantiomerically pure organic ligand such as, for example, acetamidocinnamic acid (or de alkyl ester) , itaconic acid (or the alkyl ester) , acetyl acetic acid (or the alkyl ester) into corresponding chiral compounds . Also, the United Kingdom patent GB 2289855 discloses catalysts compositions comprising compounds of generic formula R 5 6 P-Q-CHR Θ -PR 7 R 8 wherein Q is a 1,2 ferrocenyl bridging group and wherein R 9 could be an hydrogen atom. In order to illustrate that these compounds of generic formula R 5 R 6 P-Q-CHR 9 -PR 7 R 8 are well known, the GB 2289855 patent refers to the Ciba Geigy European's patent EP 564406. Nevertheless, EP 564406 patent only discloses compounds of formula R R P-Q-CHR 9 - PR 7 R 8 wherein R 9 is always different from an hydrogen atom, in such a way that the intermediary carbon atom between the ferrocenyl cycle and the phosphate atom is always a stereogenic carbon atom, in the form of their racemates and diastereoisomers or mixtures of diastereoisomers . The compounds of formula (I) are not disclosed by the EP 564406 patent, contrary to the affirmation made by GB 2289855 patent. Thus, an object of the present invention is the introduction of new ligands of the ferrocene phosphine type of formula (I) , characterized by high performance in terms of activity and enantioselectivity for the synthesis of chiral compounds. For this purpose, the ligands of formula (I) , according to the invention are prepared from the compound of formula (II) , partially according to the procedure described . in the article J.Org.Chem. 1997, 62, p.6733 by the authors O. Riant, O . Samuel , T. Flessner, S.Taudien and H.B.Kagan. The compounds of formula (II) are defined as below: wherein R3 and R4 have the same meanings as in the formula (I) . Figure 1 shows the complete process of asymmetrical synthesis of compounds of formula (I) from compound of formula (V) . Another object of the present invention is a process of asymmetrical synthesis for preparation of ferrocene phosphines of formula (I) from the compound of formula (V) , comprising the steps of: a) quantitative conversion reaction of the ferrocenylcarboxaldehyde of formula (V) by heating it in methyl-orthoformiate within a catalytic amount of APTS to obtain a dymethyl acetal derivative of formula (VI) , b) transacetylation reaction of the dymethyl acetal derivative of formula (VI) with an optically active butane-1, 2 , 3-triol followed by a methylation reaction of the obtained primary alcohol within THF by the use of sodium hydride and iodomethane to obtain the derivative of formula (VII) , c) diastereoselective ortholithiation reaction of the compound of formula (VII) obtained at step (b) within an ether solution at -78 °C with tertiobutyl-lithium followed by a substitution reaction with an R3R4-chlorophosphine to obtain the compound of formula (VIII) , wherein R3 and R4 have the save meanings as in formula ( I ) , d) hydrolysis reaction of the compound of formula (VIII) obtained at step (c) within mild conditions by means of a treatment with a catalytic amount of APTS within a mixture of water/dichloromethane to obtain the 2-R 3 R 4 - phosphinoferrocenecarboxaldehyde derivative of formula (ID , e) reduction reaction of the 2-R 3 R - phosphinoferrocene carboxaldehyde of formula (II) obtained at step (d) with a borohydrure, to obtain the primary alcohol derivative of formula (III) wherein R3 and R4 have the save meanings as in formule ( I) and f) acetylation reaction of the primary alcohol derivative of formula (III) obtained at step (e) within acetic anhydride followed by a condensation reaction with a disubstituted RiR 2 -phosphine to obtain the ferrocene phosphines of formula (I) . wherein Rl , R2 , R3 and R4 have the save meanings as previously. The compound of formula (II) is reduced by a hydride so as to obtain compound (III) defined as below: wherein R3 and R4 have the same meanings as in formula (I) . The compound of formula (III) then has its hydroxyl group substituted so as to produce the compounds of formula (I) . Another object of the present invention is the use of derivatives of formula (I) as ligands in an enantiomeric reduction process for unsaturated compounds bearing groups of formula (IV) . Said unsaturated compounds are more specifically enamides or compounds with a carbon-carbon double bond. The compounds of formula (IV) are represented below: z II (IV) wherein R 5 and R 6 are different, with R 5 selected among the group consisting of an Cι- 5 alkyl, an aryl group, an aryl group substituted by a Cι- 4 alkyl, a C-i- 4 alkoxy or a halogen, a carboxylic acid, a carboxylic ester, a Cι- 4 alkyl carboxylic acid, a Cχ. 4 alkyl carboxilate, with R6 selected from among an amide, an aryl, an aryl substituted by a C ι - 4 alkyl, a Cι-4 alkoxy or a halogen, in which Z is represents an - NR 7 , -NOR 7 or -C(R 7 ) 2 group, with R 7 selected from the group consisting of hydrogen, a C 1 - 5 alkyl, an aryl group optionally substituted by a Cι -4 alkyl or a halogen or an alkoaxyalkyl, a heteroaryl group optionally substituted by a Cι -4 alkyl or halogen or an alkoxy-alkyl . In the implementation of the catalytic system, the transition metal is preferably Rhodium and the complexes are selected from the group consisting of [Rh (formula) (I) ) COD) ]BF 4 , [Rh(formula (I))COD]PF 6 or [Rh (formula (I) ) (Cl)COD] . The catalytic quantity of the rhodium complex in relation to the quantity of formula (IV) substrate is from 1 to 50,000, preferably from 100 to 20,000 and specially preferably from 1000 to 10,000. As the examples to be presented below will show, these new formula (I) ligands exhibit high performance in terms of catalytic activity. Experimental part-Preparation of the ligand Example 1 : (S FC ) -1-dicyclohexylphosphinomethyl-2 - diphenylphosphinoferrocene . Example 1A: (SFC) -1-hydroxymethy1-2 -diphenylphosphino ferrocene. Into a flask equipped with a reflux condenser, one places under argon 6,37 g of (S Fc ) -2- diphenylphosphinoferrocene carboxaldehyde (M= 398,24); 16 mmol) and 0,38 g of sodium borohydride (M=37,83; 10 mmol) in solution in 150 ml of degassed absolute ethanol an one heats for four hours at 45°C; the colour passes from red to orange. After returning to ambient temperature, the ethanol is evaporated and the product is taken up with ether. Hydrolysis is performed by addition of 50 ml of water, followed by extraction with ether and washing with water. After drying over MgS0 4 , filtration and elimination of the solvents, one obtains 6,4 g of an orange product. Over this crude product, one adds 120 ml of hexane and 60 ml of ether. The mixture is brought to reflux until obtaining a clear solution and then slowly brought to ambient temperature and placed at -24 °C. The crystals formed are filtered and rinsed with 100 ml of hexane. After this first recrystallisation; one recovers 5,14 g of product. The mother liquors are concentrated and then purified by flash chromatography on a small height of silica gel. By eluting with a hexane/ethyl acetate mixture (3:1), one isolates a majority fraction (0,86 g) . A second recrystallisation is performed on this fraction with 10 ml of hexane and 3 ml of ether which enables isolation of 0,76 g of orange crystals. One obtains a total mass of recrystallized product of 5,9 g (14,7 mmol) which corresponds to a yield of 92%. m.p. = 102-103 °C [α] D = -282 (c = 1,00 ; CHCl 3 ) X H RMN (250 MHz, CDCl 3 ) : δ 7,51-7,46 (m, 2H, Ph) ; 7,38-7,36 (m, 3H, Ph) ; 7,26- 7,17 (m, 5H, Ph) ; 4,50 (m, 2H, Cp subst . + CH 2 ) ; 4,40 (m, 1H, CH 2 ) ; 4,28 ( , 1H, Cp subst . ) ; 4,07 (s, 5H, Cp) ; 3,72 (m, 1H, Cp subst.) ; 1,41 (t, 1H, OH) . 13 C RMN (63 MHZ, CDC1 3 ) : δ 139,4 (d,lC, " PC = 9,7 Hz, Ph) ; 136,6 (d, 1C, Jp C = 8,3 Hz, Ph) ; 134,5 (d, 2C, J C = 20,8 Hz, Ph) ; 131,9 (d, 2C, -Jpc = 17,9 Hz, Ph) ; 128,9 (1C, Ph) ; 128,0 (d, 2C, Jpc = 4,7 Hz, Ph) ; 127,8 (2C, Ph) ; 127,7 (1C, Ph) ; 92,3 (d, 1C, J " PC = 23,4 Hz, Cp subst.) ; 75,3 (d,lC, Jpc = 7,4 Hz, Cp subst.) ; 71,2 (1C, Cp subst.) ; 71,1 (1C, Cp subst.) ; 69,3 (1C, Cp subst.) ; 69,1 (5C, Cp) ; 59,3 (d,lC, J PC = 9,8 Hz, CH 2 ) . 31 P RMN (101 MHz ; CDC1 3 ) : δ - 22,80 (s, IP) MS (IE 70eV) : m/z 402 (6 %, M+2) ; 401 (32 %, M+l) ; 400 (100 %, M) ; 399 (50 %, M-H) ; 262 (46 %, M-FeCp-OH) . HRMS (IE 70 eV) : Calculated 400,0679 ; Found 400,0679. Elementary Analysis Calculated : C, 69,02 % ; H, 5,29 % ; P, 7,74 % Measured : C, 68,51 % ; H, 5,32 % ; P, 7,91 %. Example IB: (S Fc ) -1-dicyclohexylphosphinomethyl-2- diphenylphosphinoferrocene . Into a three-neck flask equipped with a reflux condenser, one places under argon 2g of (S Fc ) -1- hydroxymethyl-2 -diphenylphosphinoferrocene (M=400,26 g; 5 mmol.) and then one injects 15 ml of degassed acetic anhydride. Heating to 80°C, the alcohol dissolves and acetylation is continued for 52 hours. The solution is then brought to ambient temperature and one adds 8 ml of toluene. By azeotropic distillation, the solvents are very rapidly evaporated under the vacuum of the still where the drying is continued for one night. This forms the acetate which is directly employed in the next step. The acetate is a compound which can be isolated according to example 1C. The system is again placed under argon and one adds 30 ml of methanol and 10 g of dicyclohexylphosphine (M=198,29; 50,4 mmol). The reaction mixture is brought to reflux for one night during which it turns black. After a return to ambient temperature and concentration under vacuum of the still for 3 hours, an oil is formed. This oil is purified by chromatography over alumina (200 g) under a slight pressure of argon ( (5 KPa (50 mbar) ) . A first elution with hexane enables elimination of the excess of dicyclohexylphosphine which is directly destroyed at the column outlet over a large volume of javel water solution. After elution of at least one litter, the hexane is replaced by toluene which enables distillation of a single product and isolation of 1,43 g of orange oil. Recrystallisation is performed by heating at reflux in 80 ml of degassed absolute ethanol and then cooling at -24 °C. the yellow crystals formed are filtered and rinsed in ethanol. One obtains l,30g (2,24 mmol) of (S Fc ) -1- dicyclohexylphosphinomethyl-2 - diphenylphosphinoferrocene with a yield of 45%. m.p. = 115 °C [α] D = -160 (c = 1,00 ; CHC1 3 ) λ H RMN (250 MHz, CDC1 3 ) : δ 7,57-7,50 (m, 2H, Ph) ; 7,37-7,34 (m, 3H, Ph) ; 7,23- 7,14 (m, 5H, Ph) ; 4,52 (s, 1H, Cp subst.) ; 4,19 (m, 1H, Cp subst.) ; 3,94 (s, 5H, Cp) ; 3,69 (s, 1H, Cp subst.) ; 2,68 (dd, 1H, J " AB = 15,5 Hz et Jp H = 2,3 Hz, CH 2 ) ; 2,58 (dd, 1H, J AB = 15,5 Hz et J PU = 2,2 Hz, CH 2 ) ; 1,76-1,00 (m, 22H, Cy) . 31 P RMN (101 MHz ; CDCl 3 ) : δ - 1,81 (d, IP, Jp P = 4,5 Hz, P-Cy) ; -23,41 (d, IP, Jp P = 4,5 Hz, P-Ph) . MS (IE 70eV) : m/z 580 (4 %, M) ; 497 (100 %, M-Cy) ; 414 (6 %, M-2Cy) ; 121 (7 %, FeCp) ; 83 (11 %, Cy) ; 56 (20 %, Fe) . HRMS (IE 70 eV) : Calculated 580,211 ; Found 580,211. Elementary Analysis: Calculated: C, 72,41 % ; H, 7,30 % ; P, 10,67 % Measured : C, 72,11 % ; H, 7,21 % ; P, 10,71 %. Example 1C: (S Fc ) -1-acetoxymethyl-2-diphenylphosphino ferrocene. In a Schlenk tube equipped with a reflux condenser under argon one reacts at 80°C for 2 hours 800 mg of the compound of example 1A (2 mmol) with 8 ml of degassed acetic anhydride. After returning to ambient temperature, one adds 4 ml of toluene and the solution is concentrated under the vacuum of the still for one night so as to obtain an orange solid. This solid is dissolved in 5 ml of dichloromethane and filtered over a small height of silica which is rinsed with a hexane /ethyl acetate mixture. (4:1). After evaporation of the solvents, one recrystallizes without heating the product obtained (710 mg) in 12 ml of hexane and 3 ml of dichloromethane by simple cooling at -18 °C. The crystals formed are filtered and rinsed with hexane so as to obtain 290 mg of product. The mother liquors are concentrated for a second recrystallisation (10 ml of hexane + 2 ml of dichloromethane) which yields 260 mg. With a total of 550 mg (1,24 mmol), one obtains the recrystallized acetate with a yield of 62%. m.p. = 139 °C [α] D = "225 (c = 1,00 ; CHC1 3 ) l E RMN (250 MHz, CDCl 3 ) : δ 7,54-7,35 (m, 5H, Ph) ; 7,24-7,14 (m, 5H, Ph) ; 5,14 (dd, 1H, J AB = 11,9 Hz et J " PH = 2,3 Hz, CH 2 ) ; 4,94 (d, 1H, AB = 11,9 Hz, CH 2 ) ; 4,51 (m, 1H, Cp subst.) ; 4,30 (m, 1H, Cp subst.) ; 4,05 (s, 5H, Cp) ; 3,75 (m, 1H, Cp subst.) ; 1,57 (s, 3H, CH 3 ) . 13 C RMN (63 MHz, CDCl 3 ) : δ 170,2 (1C, CO) ; 139,4 (d,lC, J " PC = 10,2 Hz, Ph) ; 136,7 (d, 1C, Jpc = 9,2 Hz, Ph) ; 134,7 (d, 2C, J " PC = 20,8 Hz, Ph) ; 132,2 (d, 2C, J " PC = 18,3 Hz, Ph) ; 128,9 (1C, Ph) ; 128,0 (d, 2C, J " PC = 7,6 Hz, Ph) ; 127,7 (d, 2C, Jp C = 6,4 Hz, Ph) ; 127,76 (1C, Ph) ; 86,0 (d, 1C, J P C = 24,1 Hz, Cp subst.) ; 77,3 (1C, Cp subst.) ; 72,8 (d,lC, J " c = 3,4 Hz, Cp subst.) ; 72,0 (d,lC, J " P = 3,8 Hz, Cp subst.) ; 69,8 (1C, Cp subst.) ; 69,4 (5C, Cp) ; 61,5 (d,lC, J " PC = 9,6 Hz, CH 2 ) ; 20,2 (1C, CH 3 ) . 31 P RMN (101 MHz ; CDC1 3 ) : δ - 22,89 (s, IP) MS (IE 70eV) : m/z 444 (8 %, M+2) ; 443 (34 %, M+l) ; 442 (91 %, M) ; 377 (10 %, M-Cp) ; 317 (24 %, M-Cp-AcOH) ; 262 (73 %, M-FeCp-AcO) ; 261 (46 %, M-FeCp-AcOH) ; 121 (17 %, FeCp) ; 59 (16 %, AcO) ; 56 (22 %, Fe) ; 43 (100 %, Ac) . HRMS (IE 70 eV) : Calculated 442,0785 ; Found 442,0785. Elementary Analysis : Calculated : C, 67,89 % ; H, 5,25 % ; P, 7,00 % Found : C, 67,11 % ; H, 5,11 % ; P, 6,71 %. Example 2 : (S Fc ) - l -diphenylphosphino-2 - diphenylphosphinomethylf errocene . General procedures according to example 1 with: 1,20 g of the compound of example 1A (M=400,26; 3 mmol) ; 10 ml of degassed acetic anhydride; 5 ml of diphenylphosphine (M=186,20; d=l,07;28,7 mmol); 30 ml of methanol . After passage of the crude product over an alumina column, one obtains 0,63 g (1,11 mmol) of (S Fc ) - 1-diphenylphosphino-2 -diphenylphosphinomethyl ferrocene (yellow solid) . The yield of the synthesis is 37%. m.p. = 92 °C [α] D = -178 (c = 1,00 ; CHC1 3 ) X H RMN (250 MHz, CDC1 3 ) : δ 7,62-7,50 (m, 2H, Ph) ; 7,43-7,19 (m, 18H, Ph) ; 4,13 (m, IH, Cp subst.) ; 4,06 (s, IH, Cp subst.) ; 3,96 (s, 5H, Cp) ; 3,75 (s, IH, Cp subst.) ; 3,35 (s, 2H, CH 2 ) . 13 C RMN (63 MHz, CDC1 3 ) : δ 139,9 (d,lC, Jp C = 9,1 Hz, Ph) ; 139,1 (d, 1C, J- pc = 16,5 Hz, Ph) ; 138,8 (d, 1C, J " PC = 16,2 Hz , Ph) ; 137,8 (d, 1C, Jpc = 8,4 Hz, Ph) ; 135,0 (d, 2C, J " PC = 21,3 Hz, Ph) ; 133,4 (d, 2C, J " PC = 19,7 Hz , Ph) ; 132,3 (d, 2C, J " pc = 17,4 Hz, Ph) ; 132,0 (d, 2C, Jp C = 18 Hz, Ph) ; 128,8 (d, 2C, J " PC = 18,4 Hz, Ph) ; 128,3 (1C, PH) 128,2 (2C, Ph) ; 128,1 (1C, Ph) ; 128,0 (2C, Ph) 127,9 (2C, Ph) ; 127,7 (d, 2C, J " PC = 15,4 Hz, Ph) 90,4 (dd, 1C, J " pc = 26,9 et 16,7 Hz, Cp subst.) ; 75,6 (dd, 1C, J PC = 6,5 et 3,7 Hz, Cp subst.) ; 71,7 (dd,lC, J PC = 7,3 et 3,8Hz , Cp subst.) ; 70,5 (d,lC, Jp C = 3,6 Hz, Cp subst.) ; 69,8 (5C, Cp subst.) ; 68,9 (1C, Cp subst.) ; 28,8(dd,lC, J " PC = 15,5 et 10,6 Hz, CH 2 ) . 31 P RMN (101 MHz ; CDCl 3 ) : δ - 14,83 (d, IP, Jp P = 8 Hz, CH 2 PPh 2 ) ; -23,35 (d, IP, Jp P = 8 Hz, FcPPh 2 ) . MS (IE 70eV) : m/z 570 (9 %, M+2) ; 569 (36 %, M+l) ; 568 (71 %, M) ; 491 (17 %, M-Ph) ; 383 (100 %, M-PPh 2 ) ; 306 (23 %, M- PPh 2 -Ph) ; 226 (12 %, FeCpPPh) ; 121 (10 %, FeCp) . HRMS (IE 70 eV) : Calculated 568,1172 ; Found 568,1172. Elementary Analysis Found: C, 73,95 % ; H, 5,32 % ; P, 10,90 % ; Fe, 9,83 % Measured : C, 74,18 % ; H, 5,22 % ; P, 10,87 % ; Fe, 9,65 %. Examples 3 : (S Fc ) -l-dicyclopentylphosphinomethyl-2- diphenylphosphinoferrocene . General procedure according to example 1 with: l,60g of the compound of example 1A (M=400,26; 3 mmol); 10 ml of degassed acetic anhydride; 5 g of dicyclopentylphosphine (M=170,23; 29,4 mmol). 20 ml of methanol . After chromatography with toluene over alumina and an evaporation one obtains 1,15 g (2,08 mmol) (S Fc ) -l-dicyclopentylphosphinomethyl-2-diphenyl phosphinoferrocene (impure oil) , corresponding to a yield of 52%. X H RMN (250 MHz, CDC1 3 ) : δ 7,62-7,53 (m, 2H, Ph) ; 7,38-7,36 (m, 3H, Ph) ; 7,25- 7,21 (m, 5H, Ph) ; 4,58 (s, IH, Cp subst.) ; 4,24 (m, IH, Cp subst.) ; 3,95 (s, 5H, Cp) ; 3,77 (s, IH, Cp subst.) ; 2,76 (s, 2H, CH 2 ) ; 1,82-1,3 (m, 18H, Cp) . 31 P RMN (101 MHz, CDC1 3 ) : δ -3,10 (s,lP, P-Cp) ; -23,81 (s, IP, P-Ph) . General hydrogenation process. The catalytic complexes for hydrogenation were prepared in situ by adding the calculated quantity of the compound of formula (I) to the rhodium complex [Rh(VCOD) 2 ]BF 4 formed from the complex [Rh (COD) 2 acac) ] and ammonium hexafluorophosphate . The chlorinated rhodium complexes were also prepared in situ by adding the calculated quantity of the compound of formula (I) to the rhodium complex [Rh(Cl) (COD)] 2 . The catalysts can also be isolated as described in example 4. Example 4 [ (S Fc ) -l-dicyclopentylphosphinomethyl-2- diphenylphosphino ferrocene] cycloocta-1, 5-dienerhodium hexafluorophosphate . Into a Schlenk tube under argon, one places 190 mg of [ (S Fc ) -1-dicyclopentyl phosphinomethyl-2- diphenylphosphino ferrocene] (M= 552,49; 0,34 mmol.), 105 mg of [Rh (COD) (acac) ] (M= 301,23; 0,34 mmol) and 200 mg of NH 4 PF S (M=163,00; 1,2 mmol). One covers this mixture with 5 ml of dichloromethane and 3 ml of water. After 2 hours of agitation, the aqueous phase is eliminated and the organic phase is washed twice with water; the solvent is then evaporated. On the crude oil, one adds 6 ml of benzene, which is heated to reflux, with the complex remaining insoluble. After returning to ambient temperature and decantation, the supernatant is eliminated with a pipette. This operation is repeated twice, which results in 250 mg (0,27 mmol) of catalysts with a yield of 80%. m.p. = 178 °C [α] D = + 15 (c = 0,39 ; CHC1 3 ) X H RMN (250 MHz, CDCl 3 ) : δ 8,34-8,27 (m, 2H, Ph) ; 7,75-7,69 (m, 3H, Ph) ; 7,43- 7,24 (m, 5H, Ph) ; 5,25 (s, IH, COD) ; 5,09 (s, IH, COD) ; 4,71 (s, IH, Cp subst.) ; 4,36 (s, IH, COD) ; 4,32 (s, IH, Cp subst.) ; 4,25 (s, IH, Cp subst.) ; 3,65 (S, 5H, Cp) ; 3,41 (s, IH, COD) ; 3,07 (m, IH, COD) ; 2,50-1,23 (m, 27H, CH 2 + 2xCp + COD) . 31 P RMN (101 MHz ; CDC1 3 ) : δ 46,09 (dd, IP, Jp P = 32,8 Hz et J " PRh = 144 Hz, P-Cp) ; 19,16 (dd, IP, Jp P = 32,8 Hz et Jp Rh = 144,6 Hz, P-Ph) ; -143,78 (m, IP, Jp F = 711 Hz, PF 6 ) . Example 5 Bis (cycoocta-1 , 5-diene) rhodium tetra fluoroborate Into an Schlenk tube under argon, one places 212 mg of chlorocycloocta-1 , 5-diene rhodium dimmer (M= 493,08; 0,43 mmol) and 177 mg of silver tetrafluoroborate (M= 194,68; 0,91 mmol) in solution in 15 ml of dichloromethane; one then adds 111 μl of cycloocta-1, 5-diene (M= 108,18; d=0,882; 0,91 mmol) and agitation is implemented for 2 hours. An abundant precipitation of silver chloride appears. One decants the medium and transfers, via a filtration tube, the maroon supernatant solution into another Schlenk tube before eliminating the solvent. The crude product is washed with 5 ml of THF and then dried on the still to obtain 290 mg (0,71 mmol) of the complex with a yield of 83% m.p. : 204 °C X H RMN (250 MHz, CDC1 3 ) : δ 5,32 (s, 8H, 8xCH) ; 2,68-2,35 (m, 16H, 8XCH 2 ) . Hydrogenation process The substrate is introduced into an autoclave that one connects to a glass filter pump and a bottle of hydrogen which enables purging of the system. Under a hydrogen atmosphere, one adds via a syringe the catalytic solution prepared under argon in a Schlenk tube by mixing for 10 minutes 1% of [Rh(COD) 2 ]BF and 1,3% of ligand in 10 ml of methanol . The reactor is then filed at the desired pressure and intense agitation is continued for 12 hours. After the reaction, the methanol is evaporated. In the table below, we present the results obtained with the unsaturated enamides, acids an esters . The enantiomeric excesses (e.e.) were measured by HPLC on the chiral phase. Rh: [Rh (cyclooctadiene) 2 C1] 2 RH+ : [Rh (cyclooctadiene) 2 ] BF 4 Substrate/catalysts: 100 Hydrogen pressure: 101,325 KPa (1 atmosphere) Substrate 1: (Z) -alpha-acetamidocinnamic acid. Substrate 2: methyl (Z) -alpha-acetamidocinnamate. Substrate 3: (E) -N- (1-phenyl-l-propenyl) -acetamide . Substrate 4 : Itaconic acid -C0 5 H X C0 s H Substrate 5 : dimethyl itaconate Substrate 6: atropic acid Temperature : 25 °C Ligand/Rh= 1,3 Substrate/catalyst = 100

Claims: Claims 1. The ferrocene phosphines according to formula (I) below : wherein R l t R 2 , R 3 and R 4 are identical or different and are selected among the group consisting of a hydrogen, a linear or branched Cι- alkyl, a C 5-7 cycloalkyl optionally substituted by a Cι- 4 alkyl, a trifluoromethyl, a halogen, a hydroxyl or an alkoxy, a phenyl optionally substituted by a Cχ- 4 alkyl, a trifluoromethyl , a halogen, a hydroxyl or an alkoxy. 2. A process of asymmetrical synthesis for preparation of ferrocene phosphines of formula (I) from the compound of formula (V) , comprising the steps of : a) quantitative conversion reaction of the ferrocenylcarboxaldehyde of formula (V) by heating it in methyl -orthoformiate within a catalytic amount of APTS to obtain a dymethyl acetal derivative of formula (VI) , b) transacetylation reaction of the dymethyl acetal derivative of formula (VI) with an optically active butane-1, 2 , 3-triol followed by a methylation reaction of the obtained primary alcohol within THF by the use of sodium hydride and iodomethane to obtain the derivative of formula (VII) , c) diastereoselective ortholithiation reaction of the compound of formula (VII) obtained at step (b) within an ether solution at -78°C with tertiobutyl-lithium followed by a substitution reaction with an R3R4-chlorophosphine to obtain the compound of formula (VIII) , wherein R 3 and R 4 have the save meanings as in claim 1, d) hydrolysis reaction of the compound of formula (VIII) obtained at step (c) within mild conditions by means of a treatment with a catalytic amount of APTS within a mixture of water/dichloromethane to obtain the 2-R 3 R 4 - phosphinoferrocenecarboxaldehyde derivative of formula (ID , e) reduction reaction of the 2-R 3 R 4 - phosphinoferrocene carboxaldehyde of formula (II) obtained at step (d) with a borohydrure, to obtain the primary alcohol derivative of formula (III) wherein R3 and R4 have the save meanings as in claim 1 and f) acetylation reaction of the primary alcohol derivative of formula (III) obtained at step (e) within acetic anhydride followed by a condensation reaction with a disubstituted RιR 2 -phosphine to obtain the ferrocene phosphines of formula (I) . wherein R x and R 2 have the save meanings as in claim 1 3 The use of the ferrocene phosphines defined in claim 1 as ligands in an enantioselective reduction process of unsaturated compounds bearing functional groups of formula (IV) below: z II (IV) wherein R 5 and R 6 are different, R 5 is selected among the group consisting of a Cι -5 alkyl, an aryl group, an aryl group substituted by a Cι- alkyl, a C 1-4 alkoxy or a halogen, a carboxylic acid, a carboxylic ester, a Cχ- 4 alkyl carboxylic acid, a Cι- 4 alkyl carboxilate, ; R 6 is selected among the group consisting of an amide, an aryl, an aryl substituted by a Cι-4 alkyl, a C1-4 alkoxy or a halogen, in which Z is represented by an -NR , -NOR7 or -C(R 7 ) 2 group, and R 7 is selected among the group consisting of a hydrogen, a C1- 5 alkyl, an aryl group optionally substituted by a Cι_4 alkyl or a halogen or an alkoaxyalkyl, a heteroaryl group optionally substituted by a Cι_ 4 alkyl or halogen or an alkoxyalkyl. 4) Enantioselective reduction process for the unsaturated compounds bearing functional groups of formula (IV) as defined in claim 3, characterized in that: a) one mixes a ferrocene phosphine of formula (I), with an unsaturated compound bearing functional groups of formula (IV) in the presence of a transition metal complex, b) the mixture is brought to a temperature between 20°C and 100°C and c) one recovers the optically active hydrogenated compound bearing functional groups of formula (IV) as defined in claim 3. 5) A process according to claim 4 characterized in that the transition metal complex is rhodium and in that, advantageously, said complex is selected among the group consisting of [Rh (COD) (acac) ] , [Rh(COD)]BF 4 or [Rh (Cl) COD] 2 . 6) A process according to claim 4 or 5 characterized in that the quantity of the unsaturated compound bearing functional groups of formula (IV) in relation to the quantity of the transition metal complex is from 1 to 50,000, preferably from 100 to 20,000 and more preferably from 1000 to 10,000.

Inventors: ARGOUARCH GILLES, KAGAN HENRI, SAMUEL ODILE, ARGOUARCH, GILLES, KAGAN, HENRI, SAMUEL, ODILE
Applicants: PPG SIPSY S C A, PPG-SIPSY S.C.A.
Application year: 2000
Main classification: C07F17
IPC codes: B01J31, C07F17