Catalysts for nucleophilic substitution, synthesis thereof, composition containing them and use thereof

Abstract

The invention concerns novel catalysts for aromatic nucleophilic substitution. Said catalysts are compounds of the general formula (I), wherein: R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 , identical or different, are selected among hydrocarbon radicals; the Pn's, advantageously the same, are selected among metalloid elements of column V of a period higher than nitrogen; Z is a metalloid element of column V, advantageously distinct from Pn; preferably a nitrogen (N, P, As, Sb). The invention is applicable to organic synthesis.

1 - 21 . (canceled)  
     
     
         22 . A process for the preparation of a fluoroaromatic compound according to an aromatic substitution process comprising the steps of: 
 a) reacting a fluoride as nucleophilic agent and an aromatic substrate of general formula (III):      Ar-(Ξ)  (III)  wherein Ar is an aromatic radical wherein the nucleus bearing Ξ is electron-poor either because it comprises at least one hetero atom in its ring, or because the sum of the up of its substituents, besides the Ξ, is at least equal to 0.2, optionally 0.5; and    is a leaving group, optionally in the form of an anion Ξ − ,      in a polar aprotic solvent, in the presence of a catalyst which is a compound of general formula (I):                          wherein: 
 R 1 , R 2 , R 3 , R 4 , R 5  and R 6 , which are identical or different, are hydrocarbon-based radicals;  
   the Pn are phosphorus, and    Z is nitrogen    
     
     
         23 . The process as claimed in  claim 22 , wherein the compounds of formula (I) are neutral.  
     
     
         24 . The process as claimed in  claim 22 , wherein the compounds of formula (I) are cationic compounds and are optionally introduced in the form of a salt of formula (II):  
       
         
           
           
               
               
           
         
       
       wherein X −  is a counterion which is an anion or a mixtures of anion, optionally a monovalent anion.  
     
     
         25 . The process as claimed in  claim 22 , wherein said hydrocarbon-based radicals R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are: 
 alkyls,    optionally substituted aryls,    amino and imino groups, optionally in which the nitrogen linked to a Pn does not bear hydrogen,    hydrocarbyloxy groups, or    a polymer arm.    
     
     
         26 . The process as claimed in  claim 22 , wherein each of the radicals R 1 , R 2 , R 3 , R 4 , R 5  and R 6  contains not more than 20 carbon atoms.  
     
     
         27 . The process as claimed in  claim 22 , wherein the compound of formula (I) or (II) contains in total not more than 100 carbon atoms, optionally not more than 60 carbon atoms.  
     
     
         28 . The process as claimed in  claim 22 , wherein R 1 , R 2  and R 3  are identical.  
     
     
         29 . The process as claimed in  claim 22 , wherein R 4 , R 5  and R 6  are identical.  
     
     
         30 . The process as claimed in  claim 22 , wherein R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are identical.  
     
     
         31 . The process as claimed in  claim 22 , wherein R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are phenyl groups.  
     
     
         32 . The process as claimed in  claim 22 , wherein at least 3, optionally all of the radicals R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are linked to the Pn via aromatic carbon atoms and/or a nitrogen atom of a peralkylated amine or imine function.  
     
     
         33 . The process as claimed in  claim 22 , wherein not more than two of the radicals R 1  to R 3  and/or not more than two of the radical R 4  to R 6  are alkyls and in that it contains more than 12 carbon atoms.  
     
     
         34 . The process as claimed in  claim 33 , wherein the counterions X −  are anions or mixtures of anions which are sparingly nucleophilic.  
     
     
         35 . The process as claimed in  claim 34 , wherein the counterions X −  are Cl −  or Br −   
     
     
         36 . The process as claimed in  claim 22 , wherein the molar ratio between the catalyst and the nucleophilic agent being not less than 0.1%.  
     
     
         37 . The process as claimed in  claim 36 , wherein said molar ratio is not less than 0.5%.  
     
     
         38 . The process as claimed in  claim 22 , wherein the nucleophilic agent is alkali metal or alkaline-earth metal fluoride.  
     
     
         39 . The process as claimed in  claim 38  wherein said nucleophilic agent is sodium or potassium fluoride.  
     
     
         40 . The process as claimed in  claim 22  wherein Ar bears at least 1 leaving group other than Ξ.  
     
     
         41 . The process as claimed in  claim 22  wherein Ξ represents an iodine, chlorine or bromine atom or a pseudohalogen.  
     
     
         42 . The process as claimed in  claim 41  wherein Ξ represents a chlorine or bromine atom.  
     
     
         43 . The process as claimed in  claim 22  wherein Ar bears at least a non-leaving withdrawing substituent.  
     
     
         44 . The process as claimed in  claim 43  wherein the withdrawing substituent is: 
 an halogen atom    NO 2      SO 2 Alk    SO 3 Alk    Rf    CF 3      CN    CHO    COAlk    COΞ′, wherein Ξ′ is as above defined    COOAlk    Phosphone, or    phosphonate    with the symbol Alk representing a hydrogen, a linear or branched, optionally C 1  to C 4  alkyl group.    
     
     
         45 . The process as claimed in  claim 44  wherein said substituents are halogen atoms or nitro group.  
     
     
         46 . The process as claimed in  claim 44  wherein the electron withdrawing substituent(s) is (are) located in an ortho and/or para position relative to the leaving group (s) Ξ.  
     
     
         47 . The process as claimed in  claim 22  wherein the aromatic substrate is: para-chloronitrobenzene, 2,4-dichloronitrobenzene, 1,3,5-trichlorobenzene.  
     
     
         48 . The process as claimed in  claim 22  wherein the ratio between said nucleophilic agent and said aromatic substrate is between 1 and 1.5.  
     
     
         49 . The process as claimed in  claim 48  wherein the said ratio is in the region of 5/4 relative to the exchange stoichiometry.  
     
     
         50 . The process as claimed in  claim 22  wherein the solvent has a dielectric constant epsilon at least equal to about 10 and less than or equal to 100.  
     
     
         51 . The process as claimed in  claim 50  wherein the solvent has a dielectric constant epsilon greater than or equal to 25.  
     
     
         52 . The process a claimed in  claim 51  wherein the solvent has a donor index between 10 and 50.  
     
     
         53 . The process as claimed in  claim 52  wherein the solvent is DMSO or sulfolane.  
     
     
         54 . The process as claimed in  claim 22  wherein the reaction is performed at a temperature ranging from about 150 to about 250° C.