FR2838441A1 - New catalysts used to facilitate SN2 and more particularly SNAr substitutions on aromatic substrates, useful for effecting exchanges between fluorine and a higher halogen or pseudo-halogen - Google Patents

Abstract

Catalyst of specific formula is used as a catalyst for nucleophilic substitution reactions preferably aromatic substitution reactions. Catalyst of formula (I) is used as a catalyst for nucleophilic substitution reactions preferably aromatic substitution reactions. R1, R2, R3, R4, R5 and R6 = hydrocarbyl radicals; Pn (preferably the same) = metalloid group V elements of a period higher than N; and Z = group V metalloid preferably distinct from Pn, and preferably N(N, P, As, Sb). Independent claims are also included for: (1) compositions including the catalysts (I); and (2) preparation of compounds (I).

Description

is 552 in mass.

R1i R4 R2 n = Z = Pln-R5 R3 R6

  COMPOUNDS HAVING A CATALYTIC ROLE

  IN NUCLEOPHILIC SUBSTITUTION EXCHANGES

  AND METHOD FOR SYNTHESIS OF THESE COMPOUNDS

  The present invention relates to a family of compounds having a marked catalytic role in the exchange of nucleophilic substitutions, in particular the nucleophilic substitutions of order 2 and the aromatic nucleophilic substitutions which pass through a so-called Meisenheimer intermediary. This family of compounds has the formula:

R2 \ /

  Pn = Z = Pn R3 R6 or: - R ', R2, R3, R4, R5, and R6, identical or different, are chosen from hydrocarbon radicals; - Pn, advantageously the same, are chosen from the metallode elements of column V with a period greater than that of nitrogen; - Z is a metallode element of column V, advantageously distinct from Pn; preferably nitrogen (N. P. As, Sb); - Said hydrocarbon radicals R ', R2, R3, R4, R5, and R6, are generally chosen from: alkyls; optionally substituted aryls; amino and imino groups advantageously in which the nitrogen linked to a Pn does not carry hydrogen, preferably N, N-dialkoylamino N, N-diarylamino, N-aryl, N-alkylamino; alkyllimino groups, and in particular mono- and diarylketimino, trialcoyl-, dialcoyl aryl-, diarylalkoyl- and triaryl-phophinimino; hydrocarbyloxyls;

the arm of a polymer.

  on the one hand This family of compounds includes new and particularly interesting subfamilies. On the other hand the synthesis of these compounds is often difficult, especially when the compounds are not symmetrical around the atom Z. l This is why one of the aims of the invention, in addition to that of having provided a new family of catalysts, is to define subfamilies at a time

  original and with a marked catalytic character.

  Another object of the present invention is to provide a process for the synthesis of the compounds used or usable as a nucleophilic substitution catalyst of order 2 and in particular of nucleophilic substitution called SNa ,. These aims have been achieved by compounds of formula I in which the number of alkyl substituents is at most equal to 2 and whose total number of carbons is at least equal to 14, preferably to 16 per positive charge carried by the molecule. It should also be pointed out that it is particularly interesting to have molecules which are not completely symmetrical around one of the Z atoms, but also around a

Pn atoms.

  Thus, it can be indicated that the sum of the carbons of the radicals R., R2, R3, R4, R5 and R6 is greater than 12, preferably at least equal to 14,

  advantageously at least equal to 16.

  We can also express the condition on alkyls by indicating that at most 2, preferably at most one of R, R2, R3, on the one hand eVou R4, R5

  and R6 on the other hand represent an alkyl group.

  Finally, when symmetry is not desired, we can express the absence of symmetry with respect to Z by indicating that the set constituted by R., R2 and R3 must be different, at least for one of these elements , of the set R4, R5, R6. As regards the non-symmetry around one of the Pn when it is desired, this lack of symmetry can be expressed in the following manner: at least one of the R4, R5 and R6 must be different from the radical consisting of (R) (R2) (R3) pn = N-. The limitation on the number of alkyl derivatives is linked to the fact that, according to the present invention, it has been shown that it is desirable that the substituents R to R6 above all exhibit a donor character by mesomeric effect in order to better delocalize the positive charge. However, alkyl oaks with a carbon number greater than 5 may be of interest for the compatibility of the catalyst with solvents of low polar character, that is to say the solvents

  which are not miscible in all proportions with water.

  According to the present invention, the targeted compounds can be synthesized by the action of iminode of formula (R,) (R2) (R3) Pn = ZH or its derivatives on

  suitable substrates, namely trivalent compounds of Pn.

  Thus, the invention relates to a process for synthesizing a compound of general formula l: R1 R4 R2 \ pn = z = Pn

/ + -R5

  R3 R6 o: - R ', R2, R3, R4, R5, and R6, identical or different, are chosen from hydrocarbon radicals; the Pn, advantageously the same ones, are chosen from the metallode elements of column V with a period greater than that of nitrogen; - Z is a metallode element of column V, advantageously distinct from Pn; preferably nitrogen (N. P. As, Sb); comprising a stage in which a trivalent compound of Pn is reacted successively or simultaneously; To an iminode of formula (R,) (R2) (R3) Pn = ZM, where m represents a hydrogen or advantageously a cation giving a well dissociated salt, in particular chosen from quaternary ammoniums, quaternary phosphoniums and advantageously from alkalis, preferably lithium; To and if necessary a reagent capable of giving a positive halogen without

water release.

  According to one of the preparation methods, the action of the iminode is carried out in hydrogenated form, or of an advantageously alkaline salt, on a trivalent derivative of Pn [halogen> Pn-X where X represents a leaving group] carrying an advantageously halogen leaving group (preferably bromine or chlorine); The iminode anlon replaces the leaving group giving a sequence Pn = Z Pn <. The final product can be obtained by quaternization of the Pn remaining trivalent by means of a compound chosen from R4-X ', R5-X' or R6-X 'where X' is an advantageously halogen leaving group, preferably of rank at least equal to

  that of chlorine; and in particular Brome and iodine.

  The reaction can be written as follows: R2 Pn = N + \ I R2 Pn = N-P / R6-X 'IR1 l

R3 X R3 \ R3 R6

  The quaternization reaction occurs last and there can be between

  reaction times to introduce the radicals R4 and R5.

  For example, several iminode groups can be grafted: 2 R2 Pn = N R5: p X R2- Pn = N - Pn R6 X R2 P N + l -N = In R2

R3 X R3 1 R3 R6 R3

R1 / N R2 Pn R3

R1 X R1 R6-X 'R1 R1

  3 R2 Pn = N + Pn 2 Pn = N Pn R2 Pn = N + Pn N = Pn-R2]

R3 X R3 R3 R6 R3

  Usually in this way we condense the iminode with a phosphine

  already carrying two of the final substituents, here R4 and R5.

R1 IR4 R1 R4 R6-X 'R1 IR4

  R2 Pn = N + R5 -Pn R2 Pn = N - Pn-R5 R2-Pn = N = Pn-R5

R3 X R3 R3 R6

  Here too, one of the Pn, preferably both, is advantageously P. Z is advantageously nitrogen. According to another mode of action, the anlon of the iminode is transformed into a cation by oxidation, advantageously by means of a positive halogen (commonly noted in the case of bromine by Br +) or molecular, most often bromine, and is brought into contact with a trisubstituted Pn (R4) (R5) (R6) Pn; thus directly giving a compound according to the present invention. This technique is developed further: R1 RR4 Pn RS R1 R4 R3 or X R3R3 R6 R2-in = N + R5-4n2 _ R2- 4n = N + = Pn-R5 X 1 1or X 1

R3 XR3 R6

  Here too, one of the Pn is advantageously P., preferably both.

Z is advantageously nitrogen.

  The reactivity and versatility of (R) (R2) (R3) Pn = ZH and its alkaline salts (if necessary in the presence of molecular halogen, most often bromine) and especially those of (R ') (R2) (R3) P = NLi make it possible to carry out numerous syntheses of catalysts whether the molecules are already known or not. Its use constitutes an interesting access route for the compounds used

  as a catalyst in the present invention. The reactions of the examples below

after are paradigms.

  According to another embodiment of the present invention, the synthesis can be carried out by reacting a trisubstituted phosphinimine compound with a halophosphonium halide, which phosphonium carries three

hydrocarbon substituents.

  The halophosphonium halide: R4 \ R5 p R6 / X can be produced in situ by the action of a halogen on a phosphine. The reaction can be written as below where the condensation of a phophinimine with an

  triphenylphosphine in the presence of bromine.

  In this case, the synthesis of phosphiniminophosphonium bromide can be carried out by reacting phosphinimines with the dibromophosphoranes corresponding to the desired salt. The phosphinimines are obtained by deprotonation of the corresponding aminophosphonium salt in the presence of a

  strong base such as sodium amide.

  The reaction can be written as below: PIPBr2 / a2a2 PP = NH [PbP = NPP] + Br a) Br b) pp In this equation, the R 'can for example correspond to R, R2 and R3

  and the Rs can correspond to R4, R5 and R6 or vice versa.

  As far as the procedure is concerned, two options are possible, one reacting the phosphinimine with the preformed dibromophosphorane, another making the same phosphinimine react with bromine and then with phosphine

adequate.

  Obviously, the technique is performed under an inert and dry gas sky. The starting phosphonimines are generally obtained by the action of an equivalent of n-butyllithium as base on an aminophosphonium halide in general of bromide. Some phosphinimines are commercial. Dibromophosphorane is prepared beforehand by simple

  addition of a st_chiometric quantity of dibrome on the adequate phosphine.

  As indicated in the paradigmatic equation below: \ + Br 1 equiv. BuLi \ \ R3P-Nl12, R3p = Nd \ + Br

(4 + R3P = N = PR3

  1 equiv Br2 / W p ') p, PPBr2 In this equation, the R' can for example correspond to R., R2 and R3 and the R can correspond to R4, R5 and R6 or vice versa. According to a variant already mentioned above of the present invention, the synthesis of these symmetrical or asymmetrical compounds is carried out by means of an intermediate called the phosphonium azayldiide. This reaction can be schematized as below, it being understood that in this example, the phenyls can be replaced by R., R2, R3 and Ar3 can be replaced by R4, R5 and R6 Equation N 3 Br2 (excess, 2 equi Ar3P + Ph3P = N-Li [Ph3P = N-Br] Ph3P = N = PAr3 Br3 The described method of accessing tri-brominated derivatives Using a single bromine equivalent (instead of 2), the salts are synthesized directly mono brominated. Br2 (1 equi R3P + R'3P = N-Li [R'3P = N-Br] - R'3P = N = PR3 Br In this equation, the R 'can for example correspond to R, R2 and

  R3 and the Rs can correspond to R4, R5 and R6 or vice versa.

  This simple method makes it possible to obtain, in the only reaction medium (R3PNLi is prepared in situ by the action of 2 equivalents of BuLi on the corresponding aminophosphonium salt) the phosphiniminophosphonium salts

  desired in very mild conditions and very quickly.

  Of course, other salts than those of lithium can be used, but it is the one which is the easiest to manufacture from butyllithium. The reactions are carried out in usual solvents, in general possibly cyclic ethers like TH F or chlorinated derivatives like d ichloromethane, the temperature usually used is between -30 C and the temperature

  amblante, more generally between -20 C and the amblante.

  The following nonlimiting examples illustrate the invention.

  Exe mp le 1 - Synthesis of [Ph3P = N = P Bu3 -

  To a solution of 14 mmol of aminotriphenylphosphonium bromide in 125 ml of anhydrous THF, cooled to -15 ° C., 28 mm of n-BuLi (in commercial solution of hexane: Aldrich) are added dropwise over fifteen minutes. The mixture is left under constant stirring at this temperature for one hour (the diylide thus generated can be analyzed by phosphorus NMR taking the precaution of taking the sample under nitrogen). Under these conditions, 14 mmol (1 equivalent) of bromine previously dried by acid washing (H2SO4 36%) is added. The reaction mixture is then kept stirring for 2 h at a temperature of 0 to 5 C. To this solution, 14 mmoles of tributylphosphine are finally added. The mixture obtained is

  left under constant agitation for a dozen hours (one night).

  The solution obtained is filtered and the filtrate concentrated to dryness under pressure

  scaled down. 34 P NMR analysis shows the majority of the expected product.

  The residue thus recovered is taken up in dichloromethane and washed with a solution of distilled water. The organic phase is dried over MgSO4 and then concentrated to dryness. The product is redissolved in a minimum of d ichloromethane and purified by adding a large volume of ether. The recovered product undergoes an ion exchange using a Nal sodium iodide solution in order to facilitate its purification a}. After this treatment, the residue is taken up in 20 ml of ether and left cold for 3 hours (4 ° C.). The iodized product precipitates and is recovered pure by simple filtration. The product in its brominated form will be obtained by simple ion exchange first of all with a solution of AgNO3 and then with a solution of NaBr b). The oil obtained is left in the open air for several days in order to obtain a crystalline solid. a) General purification procedure by exchange of Br or Br3 with I The non-pure brominated residue recovered is taken up in dichloromethane and washed successively with 3 aqueous solutions of Nal of concentration (2.5 eq; 1.5 eq; 0, 5 eq). The organic phase is then dried over MgSO4 and

  dry concentrated for various treatments.

  b) General procedure for passing from I to Br The pure iodide obtained is redissolved in dichloromethane and washed with an aqueous solution of silver nitrate (2eq). The organic phase is then washed with a solution of distilled water in order to remove the remains of suspended silver iodide. The organic phase will then undergo 3 washes with an aqueous NaBr solution (2.5 eq; 1.5 eq; 0.5 eq). The organic solution is finally dried over MgSO4 and then concentrated to dryness under pressure.

  reduced, thus making it possible to isolate the pure brominated compound.

  3 CH3 C30H42BrNP2 / 558.520 g.mol 'Ph. B + Light yellow solid Ph-P = N = P ,, CH3 Yield 55% 31P NMR ....... (ppm) (CDCI3): 41.14 (S (a) P); 17.28 (S. (b) p) H NMR .. (ppm) (CDCI3,): 7.7- 7.58 (m, 15H, aromatics); 1.98 (m, 6H, 1CH2); 1.31 (m, 12H, 2CH2 3CH2); 0.79 (t, 9H, CH3) (ppm) (CDCI3): 133.18 (d, J4PC = 2.83 HZ, C6H5P C); 131.31 (d, J3PC = 1 1.16 HZ, C6H5 m-C); 128, 14 (d, J2PC = 13.01 HZ, C6H5 13c o-C NMR); 128.14 (d, J2PC = 13.01 HZ, C6H5 O-C); 127.69 (dd, J1 PC = 107.3 HZ, J3PaC = 1.54 HZ, C6H5 ipso-C); 26.30 (d, J1PC = 63.47 HZ, CH2); 23.09 (d, J2PC = 15.88 HZ, CH2); 23.11 (d, J3PC = 4.57

HZ, CH2); 12.99 (S. CH3)

  Mass: FAB + M-Br: 478 [NBA matrix] Exp .: C: 65.05%; H: 7.70% P: 10.50% microanal Y Y Theo .: C: 64.45%; H: 7.51%; P: 11.10%; Br: 14.31%;

  Example 2 - Synthesis of [Ph3P = N = P (o-C6H40Me) 3] -

  a) Synthesis of [Ph3P = N = P (o-C6H40Me) 3lÉ3-

  To a solution of 14 mmol of aminotriphenylphosphonium bromide in 125 ml of anhydrous THF, cooled to -15 ° C., 28 mmol of n-BuLi (in commercial solution of hexane: Aldrich) are added dropwise over fifteen minutes. . The mixture is left under constant stirring at this temperature for one hour (the diylide thus generated can be analyzed by phosphorus NMR taking the precaution of taking the sample under nitrogen). Under these conditions, 35 mmol (2.5 equiv.) Of a bromine solution previously dried by an acid wash (H2SO4 36%) are added. The reaction mixture is then kept stirring for 2 h at a temperature of 0 to 5 C. To this solution, 14 mmol of tri-o-anisylphosphine are finally added. The mixture obtained is left under stirring

  constant for a dozen hours (one night).

  The solution obtained is filtered and the precipitate purified by simple washing, firstly with a solution of 30 ml of ethanol and then with a solution of 50 ml.

  of ether. We obtained the tribrominated salt of the expected product.

  _ MeO C3gH36Br3NO3P2 Ph b 3 + a 3 OMe 868.569 g.moli Ph-P = N = P White solid Ph MeO, 3J Yield 65% 3'PRMN ... (ppm) (CH2CI2) 19.62 (d, (a ) p, J2pp = 16.04 Hz); 15.06 (s, (b) p J2p p _16.04 Hz) H NMR - (ppm) (C D Cl3,): 7.66- 6.74 (m, 27H, aromatics); 3.16 (m, (ppm) (CD Cl3): 160.90 (d, J2PC = 2.98 Hz, C6H4 oC-OMe);, 39 (d, Ar); 134.12 (d, Ani); 133.19 (d, Ani); 132.03 (d, 3C NMR Ar); 128.93 (d); 128.03 (dd, J1PC = 111.27 Hz, J3PC = 2.05 Hz, ipso-C-Ar); 121.13 (d, J3PC = 13.77 Hz, Ani); 115.12 (dd, J PC = 116.50 Hz, J3PC = 2.05 Hz, ipso-C-Anisyl); 111.97 (d, J3PC = 7, 07 Hz, Ani); 55.25 (s, OMe) Mass: FAB + M-Br: 628 [NBA matrix] Exp .: C: 53.19%; H: 4.13%; N: 1.72% Microanal se Y Theo .: C: 53.88%; H: 4.14%; N: 1.61% b) Br3 reduction to Br The tribrominated salts obtained are taken up in a dichloromethane solution and washed with an aqueous solution of sodium sulfite (2 eq). The discoloration of the organic phase is then quickly observed, a characteristic sign of the reduction of the trihalides. The organic phase is dried over MgSO4, then concentrated to dryness under reduced pressure. Phosphorus, proton and carbon spectra are good but microanalysis does not correspond

  neither monobromé nor tribromé.

  c) Synthesis of [Ph3P = N = P (o-C6H40Me) 3EB To a solution of 14 mmol of aminotriphenylphosphonium bromide in 125 ml of anhydrous THF, cooled to -15 ° C., is added dropwise for about fifteen minutes 28 mmol of n-BuLi (in commercial hexane solution: Aldrich). The mixture is left under constant stirring at this temperature for one hour (the diylide thus generated can be analyzed by phosphorus NMR taking the precaution of taking the sample under nitrogen). Under these conditions, 14 mmol (1 equivalent) of bromine previously dried by acid washing (H2SO4 36%) is added. The reaction mixture is then kept stirring for 2 h at a temperature of 0 to 5 C. To this solution, 14 mmoles of tri-anisylphosphine are finally added. The mixture obtained is left under constant stirring

  for a dozen hours (one night).

  The solution obtained is filtered and the filtrate concentrated to dryness under reduced pressure. 31p NMR analysis shows the majority of the expected product. The residue thus recovered is taken up in dichloromethane and washed with a solution of distilled water. The organic phase is dried over MgSO4 and then concentrated to dryness. The product is redissolved in a minimum of dichloromethane and purified by adding a large volume of ether in which it precipitates. _ MeO C3gH36BrNO3P2 \ b + a / OMe 708.569 9 mol Ph-P = N = P 1 /

  White solid PhMeO3 Yield 55% 31p NMR ..... (ppm) (CH2CI2): 20.17 (d, (a) p, J2pp = 16.15 Hz); 15.54 (s, (b) p, J2p p = 16.15 Hz) H NMR (ppm) (CDCI3,): 7.67-.75.75 (m, 27H, aromatics); 3.19 (m, (ppm) (CDCI3): 54.9 ppm (s, OCH3 Ani); 111.6 ppm (d, 3Jp_ c = 67 Hz, CH Ani); 114.8 ppm (d, 1JP c = 112.1 Hz, ClvAni) ; 120.8 ppm (d, 3JPC = 13.8 Hz, CH Ani); 127.1 ppm (d, 1JPc = 3CRMN 115.9 Hz, ClV Ph); 128.9 ppm (d, 3JPC = 13. 4 Hz, CH Ph); 131.8 ppm (d , 2Jpc = 11.5 Hz, CH Ph); 133.2 ppm (d, 4JPC = 2.06 Hz, CH Ph); 133.9 ppm (d, 2Jpc = 10.05 Hz, CH Ani); 135.4 ppm (apparent, 4JPC O Hz; CH Ani); 161.2 ppm (s, C-OMe Ani) Mass: FAB + M-Br: 628 [NBA matrix] Exp .: pending Microanal se Y Theo .: C: 66, -11%; H: 5, 12 %; Br: 11.28% Example 3 - Synthesis of [(Me223-p = N = p- (NMe2-3lÉ Note:

  In this case we used as limino starting substrate

  tris (dimethylamino) phosphorane [(CH3) 2N] 3P = NH. We therefore add a single equivalent of n-BuLi to generate the corresponding azayldiide. To a solution of 14 mmol dimino-tris (dimethylamino) phosphorane [(CH) 2N] 3P = NH in 125 ml of anhydrous THF, cooled to -15 C, 14 mmol of n- are added dropwise for fifteen minutes. BuLi (in commercial hexane solution: Aldrich). The mixture is left under constant stirring at this temperature for one hour (the diylide thus generated can be analyzed by phosphorus NMR taking the precaution of taking the sample under nitrogen). Under these conditions, 14 mmoles are added

  (1 equivalent) of bromine previously dried by an acid wash (36% H2SO4).

  The reaction mixture is then kept stirring for 2 h at a temperature of 0 to 5 C. To this solution, 14 mmol of tris (dimethylamino) phosphine are finally added. The mixture obtained is left under stirring

  constant for a dozen hours (one night).

  The reaction mixture is filtered and the precipitate containing the expected product recovered. This is taken up in a minimum of dichloromethane to which

  add a few drops of ethanol until the slight haze disappears completely.

  Adding a large volume of ether will remove much of the impurities. The ethereal phase is then concentrated to dryness, taken up in ether and left at low temperature overnight. The product in monobrominated form is recovered pure by simple filtration and the solid dried over P2O5 overnight

desiccator.

  Br C, 2H36BrN7P2 [(CH3) 2N P = N-P tN (CH3) 2] 3,420.31 5g.mol, Solid baige; Yield 43% 3'P NMR ...... (ppm) (CDCI3): 19.62 (s, 2P equivalent) H NMR ...... (ppm) (CDCI3): 7.36- 6.74 (t, 36H equivalent) 13C NMR (ppm) (CDCI3): 36.50 (t, J2PC = 4.78 Hz) 2nd order system Mass: FAB M-Br: 340 [NBA matrix] Exp .: C: 34.29%; H: 8.64%; N: 23.00%; Br: 19.16% microanalse Y Theo .: C: 34.26%; H: 8.51%; N: 23.31%; Br: 19.03%; Example 4 - Synthesis of [(Me23-P = N = PBu3l To a solution of 14 mmol of tributylphosphine in 70 ml of anhydrous dichloromethane, 14 mmol of a dibroma solution previously diluted in 10 ml of dichloromethane is added dropwise -5 C. The mixture is left under stirring for 1 hour at a temperature of 0 to

-5OC in situ jormation of Bu3PBr2).

  After adding 1.5 equivalents of triethylamine, 14 mmol of the imino-

  tris (dimethylamino) phosphorane [(CH3) 2N] 3P = NH in 14 ml of THF are then added to the solution of dibromotributylphosphorane Bu3PBr2. The mixture

  resulting is left stirring overnight at room temperature.

  The solution obtained is evaporated to dryness under reduced pressure. The residue recovered is taken up in ether, then filtered. The pasty, semisolid product is taken up in dichloromethane and washed with a solution of distilled water. The organic phase is dried over MgSO4, filtered and then concentrated to dryness. The product is

  ensu ite m is suspended in ether and left u ne it at low tem peratu re.

  The pasty solid contained in the ethereal phase is triturated in a cold alcohol bath at -70 ° C. and the solution is filtered. The pure product is finally dried with

desiccator on P2Os.

  CH3 Br JJ ClgH4sBrN4P2 (CH3) 2NIP = NP, CH3 459,432g.mol 1 Light brown solid Yield 48.8% CH3 31p NMR .... (ppm) (CDCI3): 29.62 (d, Jpp = 30.65 Hz); 23.18 (d, J'pp =, 65 Hz) (ppm) (CDCI3,): 2.6 (dd, 18H); 2 to 1.8 (m, 1CH2, 6H); 1.55 to 1 H NMR 1.3 (m, 2CH2-3CH2, 12H); 0.87 (t, CH3, 9H) AT (ppm) (CDCI3): 36.76 (d, J2pC = 4.47 Hz, MeN); 26.85 (dd, 13c NMR J1PC = 66.24 Hz, J3PC = 1.49 Hz, CH2); 23.36 (d, J2pc = 11.54 Hz, CH2); 23.18 (s, CH2CH3); 13.20 (s, CH3) Mass: FAB + M-Br: 380 [NBA matrix] Exp .: C: 45.66%; H: 9.73%; N: 11.70%; P: 12.90% microanal se Y Theo .: C: 47.01%; H: 9.79%; N: 12.18%; P: 13.40%; Example 5 - Synthesis of [(Me23-P = N = PPh3] É To a solution of 14 mmol of triphenylphosphine in 70 ml of anhydrous dichloromethane, 14 mmol of a solution of dibroma previously diluted in 10 ml of is added dropwise dichloromethane at -5 ° C. The mixture is left under stirring for 1 hour at a temperature of 0 to

-5 C In situ formation of Ph3PBr2).

  After adding 1.5 equivalents of triethylamine, 14 mmol of the imino-

  tris (dimethylamino) phosphorane [(CH3) 2N] 3P = NH in 14 ml of THF are then

  added to the solution of dibromotriphenylphosphorane Ph3PBr2.

  After stirring overnight at room temperature, the reaction mixture is concentrated to dryness under reduced pressure. The solid residue is taken up in ether and then filtered. The precipitate recovered is dissolved in 150 ml of dichloromethane and washed twice with 20 ml of distilled water. The organic phase is dried over MgSO4 and then evaporated to dryness. The white solid obtained is suspended in 50 ml of ether and left stirring for 30 minutes. The pure product is obtained by simple filtration and dried in a desiccator overnight on P2O5 C24H33BrN4P2 Br 519.4 g.mol '[(CH) NP N PPh White solid Yield 67% 31p NMR ....... (ppm) ( CH2Cl2): 26.48 (d, J2pp = 37.3 Hz); 13.45 (d, J2pp = 37.3 Hz) H NMR .... (ppm) (CDCI3,): 2.52 (d, CH3, 18H, J3PH = 10.35 Hz); 7.57 to 7.44 (m, aromatic, 15H) At (ppm) (CDCI3): 152.72 (d, J4PC = 3.01Hz); 150.92 (d, J3PC = 13c NMR 11.06 Hz) 148, 68 (d, J2PC = 13.20 Hz); 147.21 (dd, J PC = 108.64 Hz, J3PC = 2.54 Hz); 56, 25 (d, J2pc = 4.52 Hz, MeN) Mass: FAB + M-Br: 439 [NBA matrix] Exp .: C: 45.66%; H: 9.73%; N: 11.70%; P: 12.90% microanal se Y Theo .: C: 47.01%; H: 9.79%; N: 12.18%; P: 13.40%; Example 6 - Synthesis of Bu3-P = N = PBu3 + Br This example shows the advantage of the synthesis technique, although the product

  is not among the preferred products.

  Thus, to a solution of 14 mmol of tributylphosphine in 70 ml of anhydrous dichloromethane, 14 mmol of a solution of dibroma previously diluted in 10 ml of dichloromethane at 5 ° C. is added dropwise. The mixture is left under stirring for 1 hour at a temperature of 0 to

  -5 C (formation in s / tu of Bu3PBr2).

  After adding 1.5 equivalents of triethylamine, 14 mmol Bu3P = NH (prepared by the action of 1 equivalent of BuLi on [Bu3PNH2] + Br) in 14 ml of

  THF are then added to the dibromotributylphosphorane solution Bu3PBr2.

  After overnight reaction, the reaction mixture is concentrated to dryness and the residue recovered taken up in 40 ml of THF. The solution is filtered and the organic phase containing the expected salt evaporated to dryness. This is not entirely pure, because the residue contains approximately 25% of the starting aminophosphonium salt which we have not managed to separate by recrystallization (based on the NMR of the Phosphorus). The precipitate is then heated at 160 ° C. for 5 hours until the residual starting salt has disappeared. Recrystallization of the residue

  in CCI then makes it possible to obtain the expected product with a yield of 52%.

  C24H54BrNP2 Br 498.549 g.mol, BU3P = N = PBU3 Yellow oil Yield 52% 3'P {1H} NMR (CH2CI: 36.3 ppm (Bu3PNPBu3, Br) (57.2 ppm (Bu3PNH2, Br)) H NMR ( CDCI3,): 0.93 ppm (t, 18H, CH3): 1.45 ppm (m, 24H, CH2-CH2); 2.03 ppm (m, 12H, -CH2-P) (CDCI3J: 13.66 ppm (s, CH3); 23.88 ppm (d, 2Jp = 15.6 Hz, 3C NMR CH2 O; 24.02 ppm (d, 3Jp = 4.5 Hz, CH2; 27.15 ppm (d / d, Jp c = 65. 5 Hz, 3Jp 0.4 Hz, CH Mass: FAB + M-Br: 418 [NBA matrix] microanalysis In progress The reactivity and versatility of (R,) (R2) (R3) Pn = ZH, and its alkaline salts (if necessary in the presence of halogen molecular, most often bromine) and especially those of (R,) (R2) (R3) P = N Li makes it possible to carry out numerous synthesis of catalysts whether the molecules are already known or not. Its use constitutes an access route interesting for the compounds used as catalyst in the present invention. The reactions below are

examples.

  Example of catalysts The reaction of Ph3P = NLi on PCI3 leads quantitatively to the synthesis of protonated triphosphinimine 3. The synthesis of this compound is carried out by intermediate passage through the corresponding triphosphinimine (Ph3P = N) 3P, the latter having a doublet free on the phosphorus atom whose electronic density is considerably increased by the triple donor effect of the three groups Ph3P = N-. This triphosphinimine then becomes basic enough to protonate in a few minutes at 20 C, probably attacking the protons of THF, and precipitating in this solvent in the form of a salt.

phosphonium [(Ph3P = N) P-H] + Cl-.

  This availability of the doublet makes this compound an interesting intermediary

  for later quaternization and form a compound according to the invention.

  Procedure: To a solution of Ph3P = NLi (4.2 mmol, 3 equivalents) in 50 ml of THF to C is added suddenly with the syringe trichlorophosphine (1.4 mmol, 1 equivalent). The mixture is left to stir at this temperature for minutes, a white precipitate of N, N ', N "- (phosphinlo) tristriphenylphosphinimine then forms in the medium. This precipitate is filtered, rinsed with THF, and obtained

pure with a yield of 95%.

  Cl THF 20 C 30 min Ph. P = N 3 Ph3P = NL '+ P-Cl' ', Ph3P = N-, PH Cl Cl Ph3P = N (Ph3P = N) 3P is observed in 34P NMR after action of n- butyllithium on a solution of salt isolated 3 in dimethylsulfoxide at 20 C. Triphosphinimine, very sensitive to humidity and oxygen, could not be isolated. After the deprotonation, then recovery of elementary sulfur is obtained a mixture of starting phosphonium salt (12%) and oxidized triphosphinimines (Ph3P = N) 3P = 0

  (52%) and sulfur (Ph3P = N) 3P = S (24%).

  The pKa of the couple [(Ph3P = N) 3P-H] + / (Ph3P = N) 3P is between that of Ph3P = NH / Ph3P = NLi and that of the couple n-butane / n-butyllithium, that is- to say between

28 and 43.

Example 8

  Addition on N-diphenylphosphino-triphenylphosphinimine 1 of an equivalent of chlorodiphenylphosphine to lead to a phosphinimine at

sequence P = N-P-P 2.

Ph THF, 20 C, 12h Ph. P = N ± P-P 'CI-

  Ph3P = N-PPh2 + Ci-F 3 1 2 To a solution of N-diphenylphosph inotriphenyl phosphi ni mine (4 m mol) in THF is added dropwise at 20 C, Ph2PCI (4 mmol). The solution is stirred for 12 hours at this temperature. Compound 2 precipitates over time. The solution is then filtered, the white solid collected is then recrystallized from acetonitrile and is obtained with a yield of 73%. Its structure is

  confirmed by pF., mass spectrometry, 34 P NMR, IR.

  This compound was once described in 1969 by Madersteig (Mardersteig, H.G.;

  Meinel, L .; Noth, H. Z. Anorg. Alig. Chem. 1969, 368, 254-261 or Z. Anorg. Alig.

  Chem. 1970, 375, 272-280) from Ph3P = NSiMe3 and two equivalents from Ph2PCI.

Claims (6)

  1. Cationic compound useful as a nucleophilic substitution catalyst of general formula l: R1 R4 R2 \ pn = z = Pn / + l -R5 R3 R6 o: - R., R2, R, R4, R5, and R6, identical or different, are chosen from hydrocarbon radicals; the Pn, advantageously the same ones, are chosen from the metallo elements of column V of a period greater than that of nitrogen; - Z is a metalloid element of column V, advantageously distinct from Pn; preferably nitrogen (N. P. As, Sb); characterized by the fact that at most two of R to R3 and / or at most two R4 to R6 are alkyls and by the fact that it contains more than 12 carbon atoms. 2. Process for the synthesis of compound of general formula l: R1 R4 R2 \ /   Pn = Z = Pn R3 R6 o: - R., R, R3, R4, R5, and R6, identical or different, are chosen from hydrocarbon radicals; the Pn, advantageously the same ones, are chosen from the metallo elements of column V of a period greater than that of nitrogen; - Z is a metalloid element of column V, advantageously distinct from Pn; preferably nitrogen (N. P. As, Sb); characterized by the fact that it comprises a step in which one reacts successively or simultaneously: To a trivalent compound of Pn; To an iminoid of formula (R,) (R2) (R3) Pn = ZM, where m represents a hydrogen or advantageously a cation giving a well dissociated salt, in particular chosen from quaternary ammoniums, quaternary phosphoniums and advantageously from alkalis, preferably lithium; To and if necessary a reagent capable of giving a positive halogen without release of water.   3. Method according to claim 2, characterized in that the reactive led it capable of giving a positive halogen without release of water is a   molecular halogen, preferably bromine.   4. Method according to claims 2 and 3, characterized in that said   iminoid is subjected to the action of a halogen (X2) before or during contact with the trivalent compound of formula P (R4) (R5) (R6) to give one of the following reaction sequences: R1 X R1R4 -I n-R5 R1 R4 R2 Pn = N 2 R2Pn = NX R2Pn = N-Pn-Rs X R3 or X R3 R3 R6 R1 R4 X R1 R4   R2 Pn = N + R5 in 2 + R2 Pn = N ± Pn-Rs X 1 1 or X 1 R3 X R3 R6   5. Method according to claims 2 and 3, characterized in that said   trivalent compound of Pn is a phosphine of formula P (R4) (R5) (R6) and is subjected to the action of a halogen, advantageously bromine (Br2), to form at least temporarily a halogenophosphonium halide of formula: R4 R5 \, X   R6 X before or during the contact with the iminode or advantageously a   of its salts and o R1, R2, R3, R4, R5 and R6 are defined above.   6. Method according to claim 2, characterized in that said trivalent derivative of Pn is halogenated and that one does not add a reagent capable of giving a positive halogen without dogagement of water. so as to meter one of the following reactions: R1 IR4 R1 R4 R6-X 'R1 R4 R2Pn = N + R5 Pn R2 Pn = N - Pn-R5 R2 Pn = N - Pn-R5 R3 X R3 R3 R6